MPLS Command Reference for Cisco ASR 9000 Series Routers

backoff

To configure the parameters for the Label Distribution Protocol (LDP) backoff mechanism, use the backoff command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

backoff initial maximum

Syntax Description


`initial`	Initial backoff delay, in seconds. Range is 5 to 2147483 .
`maximum`	Maximum backoff delay, in seconds. Range is 5 to 2147483 .

Command Default

initial : 15

maximum : 120

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.0	No modification.
Release 3.3.0	No modification.
Release 3.4.0	No modification.
Release 3.5.0	No modification.
Release 3.6.0	No modification.
Release 3.7.0	No modification.
Release 3.7.2	This command was introduced.
Release 3.8.0	No modification.

Usage Guidelines

The LDP backoff mechanism prevents two incompatibly configured label switch routers from engaging in an unthrottled sequence of session setup failures. If a session setup attempt fails (due to incompatibility), each Label Switching Router (LSR) delays the next attempt, increasing the delay exponentially with each successive failure until the maximum backoff delay is reached.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to configure the initial backoff delay to 30 seconds and the maximum backoff delay to 240 seconds:


RP/0/RP0RSP0/CPU0:router:hostname# configure
RP/0/RP0RSP0/CPU0:router:hostname(config)# mpls ldp
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# backoff 30 240

Related Commands


Command	Description
show mpls ldp backoff	Displays information about the configured session setup backoff parameters and LDP peers.
show mpls ldp parameters	Displays current LDP parameter settings.

clear mpls ldp forwarding

To clear (or reset) the MPLS Label Distribution Protocol (LDP) forwarding rewrites, use the clear mpls ldp forwarding command in EXEC modeXR EXEC mode.

clear mpls ldp [vrf vrf-name] [ipv4 | ipv6] forwarding [prefix/length ]

Syntax Description


vrf `vrf-name`	(Optional) Clears the VRF information for the specified VRF.
ipv4	(Optional) Specifies IP version 4 address family.
ipv6	(Optional) Specifies IP version 6 address family.
`prefix`	(Optional) Destination prefix, written in A.B.C.D format.
`length`	(Optional) Network mask length, in bits. Range is 0 to 32.

Command Default

No default behavior or values

Command Modes

EXEC modeXR EXEC mode

Command History


Release	Modification
Release 4.0.1	This command was introduced.
Release 5.0.0	This command was introduced.
Release 5.1.1	The vrf and ipv4 keywords were added.
Release 5.3.0	The ipv6 keyword was added.

Usage Guidelines

This command resets LDP installed forwarding state for all prefixes or a given prefix. It is useful when installed LDP forwarding state needs to be reprogrammed in LSD and MPLS forwarding.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

This example shows how to clear (or reset) the MPLS LDP forwarding rewrites using the clear mpls ldp forwarding command:



RP/0/RP0RSP0/CPU0:router:hostname# clear mpls ldp forwarding

Related Commands


Command	Description
show mpls ldp forwarding	Displays the LDP forwarding state installed in MPLS forwarding.
show mpls forwarding	Displays the contents of the MPLS Label Forwarding Information Base (LFIB).
graceful-restart (MPLS LDP)	Configures the LDP graceful restart feature.
show mpls ldp bindings	Displays the contents of LDP LIB.

clear mpls ldp msg-counters neighbor

To clear the Label Distribution Protocol (LDP) message counters, use the clear mpls ldp msg-counters neighbor command in EXEC modeXR EXEC mode.

clear mpls ldp [vrf vrf-name] msg-counters neighbor [lsr-id | ldp-id]

Syntax Description


vrf `vrf-name`	(Optional) Clears the VRF information for the specified VRF.
`lsr-id`	LSR ID of neighbor in A.B.C.D format.
`ldp-id`	LDP ID of neighbor in A.B.C.D: format.

Command Default

No default behavior or values

Command Modes

EXEC modeXR EXEC mode

Command History


Release	Modification
Release 3.0	No modification.
Release 3.3.0	No modification.
Release 3.4.0	No modification.
Release 3.5.0	No modification.
Release 3.6.0	No modification.
Release 3.7.0	No modification.
Release 3.7.2	This command was introduced.
Release 3.8.0	No modification.

Usage Guidelines

Use the clear mpls ldp msg-counters neighbor command to clear the statistics on message counters for a specific neighbor (IP address) or for all neighbors. These message counters count the number of LDP protocol messages sent to and received from LDP neighbors.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to clear message counters for neighbor 10.20.20.20:


RP/0/RP0RSP0/CPU0:router:hostname# clear mpls ldp msg-counters neighbor 10.20.20.20

Related Commands


Command	Description
show mpls ldp statistics msg-counters	Displays statistics about the type and count of the messages sent and received from neighbors.

clear mpls ldp neighbor

To force Label Distribution Protocol (LDP) session restart, use the clear mpls ldp neighbor command in EXEC modeXR EXEC mode.

clear mpls ldp [vrf all] [vrf vrf-name] neighbor [ip-address | ldp-id]

Syntax Description


vrf all	(Optional) Clears all LDP configured VRF neighbors.
vrf `vrf-name`	(Optional) Clears the VRF information for the specified VRF.
`ip-address`	(Optional) Neighbor IP address.
`ldp-id`	(Optional) Neighbor LDP ID in A.B.C.D: format.

Command Default

No default behavior or values

Command Modes

EXEC modeXR EXEC mode

Command History


Release	Modification
Release 3.4.0	No modification.
Release 3.5.0	No modification.
Release 3.6.0	No modification.
Release 3.7.0	No modification.
Release 3.7.2	This command was introduced.
Release 3.8.0	No modification.
Release 3.9.0	No modification.
Release 5.1.1	The vrf and vrf all keywords were added.

Usage Guidelines

Use the clear mpls ldp neighbor command to restart a single LDP session or all LDP sessions (without restarting the LDP process itself).

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to force an unconditional LDP session restart:


RP/0/RP0RSP0/CPU0:router:hostname# clear mpls ldp neighbor 10.20.20.20

Related Commands


Command	Description
show mpls ldp neighbor	Displays information about LDP neighbors.

clear mpls ldp nsr statistics neighbor

To clear the nonstop routing (NSR) statistics, use the clear mpls ldp nsr statistics neighbor command in EXEC modeXR EXEC mode.

clear mpls ldp [vrf vrf-name] nsr statistics neighbor [lsr-id | ldp-id]

Syntax Description


vrf `vrf-name`	(Optional) Displays the VRF information for the specified VRF.
`lsr-id`	(Optional) LSR ID of neighbor in A.B.C.D format.
`ldp-id`	(Optional) LDP ID of neighbor in A.B.C.D: format.

Command Default

No default behavior or values

Command Modes

EXEC modeXR EXEC mode

Command History


Release	Modification
Release 5.1.1	This command was introduced.

Task ID


Task ID	Operation
mpls-ldp	read

Examples

The following example shows how to clear NSR statistics for neighbor 10.20.20.20:


RP/0/RP0RSP0/CPU0:router:hostname#clear mpls ldp nsr statistics neighbor 10.20.20.20

debug mpls ldp rsi

To enable the display of MPLS LDP router space infrastructure (RSI) debugging events, use the debug mpls ldp rsi command in EXEC modeXR EXEC mode. To disable the display of MPLS LDP RSI debugging information, use the no form of this command.

debug mpls ldp rsi [location node-id]

Syntax Description


location `node-id`	(Optional) Displays location information for the specified node ID.

Command Default

No default behavior or values

Command Modes

EXEC modeXR EXEC mode

Command History


Release	Modification
Release 5.1.1	This command was introduced.

Task ID


Task ID	Operation
mpls-ldp	read

Examples

The following example shows how to enable MPLS LDP RSI debugging events:



RP/0/RP0RSP0/CPU0:router:hostname# debug mpls ldp rsi

debug mpls ldp vrf

To enable the display of MPLS LDP virtual routing and forwarding (VRF) debugging events, use the debug mpls ldp vrf command in EXEC modeXR EXEC mode. To disable the display of MPLS LDP VRF debugging information, use the no form of this command.

debug mpls ldp vrf [location node-id]

Syntax Description


location `node-id`	(Optional) Displays location information for the specified node ID.

Command Default

No default behavior or values

Command Modes

EXEC modeXR EXEC mode

Command History


Release	Modification
Release 5.1.1	This command was introduced.

Task ID


Task ID	Operation
mpls-ldp	read

Examples

The following example shows how to enable MPLS LDP VRF debugging events:



RP/0/RP0RSP0/CPU0:router:hostname# debug mpls ldp vrf

default-route

To enable Multiprotocol Label Switching (MPLS) switching for IP default route by allocating and advertising non-null label, use the default-route command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

default-route

Syntax Description

This command has no arguments or keywords.

Command Default

Allocates null (implicit or explicit) local label for IP default route prefix 0.0.0.0/0.

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.4.0	No modification.
Release 3.5.0	No modification.
Release 3.6.0	No modification.
Release 3.7.0	No modification.
Release 3.7.2	This command was introduced.
Release 3.8.0	No modification.
Release 3.9.0	No modification.

Usage Guidelines

When the IP default route 0.0.0.0/0 is configured on an egress router, it is advertised through Interior Gateway Protocol (IGP) to other routers to enable default IP forwarding. When MPLS LDP is configured and establishing label switch paths (LSPs) for other prefixes, you can emulate default forwarding and switching for MPLS in the same way as IP forwarding. To do so, allocate a non-null local label and advertise this label to its peers.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to enable default MPLS switching for default prefix:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# default-route

Related Commands


Command	Description
show mpls ldp bindings	Displays LDP label bindings.
show mpls ldp forwarding	Displays LDP installed forwarding state.

default-vrf implicit-ipv4 disable

To disable the implicitly enabled IPv4 address family for default VRF, use the default-vrf implicit-ipv4 disable command in MPLS LDP configuration mode.

default-vrf implicit-ipv4 disable

This command has no keywords or arguments.

Command Default

No default behavior or values

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 5.3.0	This command was introduced.

Task ID


Task ID	Operation
mpls ldp	read, write

Examples

The following example shows how to disable the implicitly enabled IPv4 address family for default VRF:


RP/0/0/CPU0:ios#configure
RP/0/0/CPU0:ios(config)#mpls ldp
RP/0/0/CPU0:ios(config-ldp)#router-id 5.5.5.5
RP/0/0/CPU0:ios(config-ldp)#default-vrf implicit-ipv4 disable

discovery hello

To configure the interval between transmission of consecutive Label Distribution Protocol (LDP) discovery hello messages and the holdtime for a discovered LDP neighbor, use the discovery hello command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

discovery hello {holdtime seconds | interval seconds}

Syntax Description


holdtime	Sets the time, in seconds, a discovered LDP neighbor is remembered without receipt of an LDP hello message from the neighbor. Default is 15.
interval	Sets the time, in seconds, between consecutive hello messages. Default is 5.
`seconds`	Time value, in seconds. Range is 1 to 65535 (65535 means infinite).

Command Default

holdtime : 15

interval : 5

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.0	No modification.
Release 3.3.0	No modification.
Release 3.4.0	No modification.
Release 3.5.0	No modification.
Release 3.6.0	No modification.
Release 3.7.0	No modification.
Release 3.7.2	This command was introduced.
Release 3.8.0	No modification.
Release 3.9.0	No modification.

Usage Guidelines

No specific guidelines impact the use of this command.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to configure the link hello holdtime to 30 seconds:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# discovery hello holdtime 30

The following example shows how to configure the link hello interval to 10 seconds:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# discovery hello interval 10

Related Commands


Command	Description
	Configures targeted-hello messages.

discovery instance-tlv disable

To disable transmit and receive processing for Type-Length-Value (TLV), use the discovery instance-tlv disable command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

discovery instance-tlv disable

Syntax Description

This command has no arguments or keywords.

Command Default

No default behavior or values

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.5.0	No modification.
Release 3.6.0	No modification.
Release 3.7.0	No modification.
Release 3.7.2	This command was introduced.
Release 3.8.0	No modification.
Release 3.9.0	No modification.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to disable transmit and receive processing for TLV:


RP/0/RP0RSP0/CPU0:router:hostname# configure
RP/0/RP0RSP0/CPU0:router:hostname(config)# mpls ldp
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# discovery instance-tlv disable

Related Commands


Command	Description
	Configures targeted-hello messages.

discovery targeted-hello

To configure the interval between transmission of consecutive Label Distribution Protocol (LDP) discovery targeted-hello messages, the hold time for a discovered targeted LDP neighbor, and to accept targeted hello from peers, use the discovery targeted-hello command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

discovery targeted-hello address-family {ipv4 | ipv6} {accept | [from acl] | holdtime seconds | interval seconds}

Syntax Description


accept	Accepts targeted hellos from any source.
ipv4	Specifies IP version 4 address family.
ipv6	Specifies IP version 6 address family.
from `acl`	(Optional) Accepts targeted hellos from LDP peers as permitted by the access-list.
holdtime	Configures the time a discovered LDP neighbor is remembered without receipt of an LDP hello message from a neighbor.
interval	Displays time between consecutive hello messages.
`seconds`	Time value, in seconds. Range is 1 to 65535.

Command Default

accept : Targeted hello messages are not accepted from any source (neighbor).

holdtime : 90

interval : 10

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.0	No modification.
Release 3.3.0	No modification.
Release 3.4.0	No modification.
Release 3.5.0	No modification.
Release 3.6.0	No modification.
Release 3.7.0	No modification.
Release 3.7.2	This command was introduced.
Release 3.8.0	No modification.
Release 3.9.0	No modification.
Release 5.3.0	The ipv6 keyword was added.

Usage Guidelines

LDP supports IPv4 standard access lists only.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to configure the targeted-hello holdtime to 45 seconds:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# discovery targeted-hello holdtime 45

The following example shows how to configure the targeted-hello interval to 5 seconds:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# discovery targeted-hello interval 5

The following example shows how to configure acceptance of targeted hellos from all peers:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# discovery targeted-hello accept

The following example shows how to configure acceptance of targeted hello from peers 10.1.1.1 and 10.2.2.2 only:


RP/0/RP0RSP0/CPU0:router:hostname(config)# ipv4 access-list peer_acl_10
RP/0/RP0RSP0/CPU0:router:hostname(config-ipv4-acl)# permit 10.1.1.1
RP/0/RP0RSP0/CPU0:router:hostname(config-ipv4-acl)# permit 10.2.2.2
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# discovery targeted-hello accept from peer_acl_10

Related Commands


Command	Description
show mpls ldp discovery	Displays LDP discovery information.
show mpls ldp parameters	Displays LDP parameters information.

discovery transport-address

To provide an alternative address for a TCP connection, use the discovery transport-address command in MPLS LDP interface configuration mode. To return to the default behavior, use the no form of this command.

[vrf vrf-name [interface type interface-path-id]] address-family ipv4 | ipv6 discovery transport-address {ip-address | interface}

Syntax Description

vrf vrf-name

(Optional) Specifies the VRF name.

interface type

(Optional) Interface type. For more information, use the question mark (?) online help function.

interface-path-id

Physical interface or a virtual interface.

Note

Use the show interfaces command to see a list of all possible interfaces currently configured on the router.

For more information about the syntax for the router, use the question mark (?) online help function.

address-family ipv4

Specifies IP version 4 address family.

ipv6

Specifies IP version 6 address family.

ip-address

IP address to be advertised as the transport address in discovery hello messages.

interface

Advertises the IP address of the interface as the transport address in discovery hello messages.

Command Default

LDP advertises its LDP router ID as the transport address in LDP discovery hello messages.

Command Modes

MPLS LDP interface configuration

Command History


Release	Modification
Release 3.0	No modification.
Release 3.3.0	No modification.
Release 3.4.0	No modification.
Release 3.5.0	No modification.
Release 3.6.0	No modification.
Release 3.7.0	No modification.
Release 3.7.2	This command was introduced.
Release 3.8.0	No modification.
Release 3.9.0	No modification.
Release 5.1.1	The following items were added: The vrf keyword was added. The interface keyword was added. The address-family ipv4 keyword was added.
Release 5.3.0	The ipv6 keyword was added.

Usage Guidelines

Establishing an LDP session between two routers requires a session TCP connection. To establish the session TCP connection, each router must know the transport address (IP address) of the other router.

The LDP discovery mechanism provides the means for a router to advertise transport addresses. Transport address is implicit or explicit. Implicit addresses do not appear as part of the contents of the discovery hello messages sent to the peer. If explicit, the advertisement appears as part of the contents of discovery hello messages sent to the peer.

The discovery transport-address command modifies the default behavior described above. Using the interface keyword, LDP advertises the IP address of the interface in LDP discovery hello messages sent from the interface. Using the ip-address argument, LDP advertises the IP address in LDP discovery hello messages sent from the interface.

Note

When a router has multiple links connecting it to its peer device, the router must advertise the same transport address in the LDP discovery hello messages it sends on all such interfaces.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to specify an exiting address (10.10.3.1) as the transport address on an interface POS 0/1/0/0:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# interface POS 0/1/0/0 
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp-if)# address-family ipv4
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp-if-af)#discovery transport-address 10.10.3.1
  
RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp neighbor
  
  Peer LDP Identifier: 10.44.44.44:0
    TCP connection: 10.44.44.44:65520 - 10.10.3.1:646
    Graceful Restart: Yes (Reconnect Timeout: 15 sec, Recovery: 180 sec)
    State: Oper; Msgs sent/rcvd: 13/9
    Up time: 00:00:11
    LDP Discovery Sources: 
         POS 0/1/0/0
    Addresses bound to this peer:
      10.10.3.2       10.44.44.44

Related Commands


Command	Description
show mpls ldp discovery	Displays the status of the LDP discovery process.
show mpls ldp neighbor	Displays information about LDP neighbors.

downstream-on-demand

To configure MPLS Label Distribution Protocol (LDP) downstream-on-demand mode, use the downstream-on-demand command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

[vrf vrf-name session] downstream-on-demand with access-list

Syntax Description


vrf `vrf-name`	(Optional) Displays the VRF information for the specified VRF.
session	(Optional) Configures session parameters.
with	Displays access list of LDP peers.
`access-list`	IPv4 access-list name.

Command Default

No default behavior or values

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 6.0	This command was introduced.

Usage Guidelines

No specific guidelines impact the use of this command.

Task ID


Task ID	Operation
mpls-ldp	read, write

Examples

This is a sample output from the downstream-on-demand command:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# downstream-on-demand with access-list

entropy-label

To enable entropy label LDP signaling on the transit LSR in an MPLS network, use the entropy-label command in MPLS LDP configuration mode.

To remove this configuration, use the no form of the command.

entropy-label [ add-el ]

no entropy-label [ add-el ]

Syntax Description


add-el	(Optional) Specifies that the entropy label and indicator be added to the MPLS label stack. Enable the add-el keyword on the ingress router.

Command Default

None

Command Modes

MPLS LDP configuration mode.

Command History


Release	Modification
Release 6.6.2	This command was introduced.
Release 7.2.2	The add-el option was added as an ingress router configuration.

Usage Guidelines

Entropy labels are used by the transit LSR for efficient load balancing of traffic through the MPLS network. An entropy label is inserted on top of the MPLS label stack at the transit LSR . Entropy labels help the smooth operation of the transit LSRs by relieving them of the task of deep packet inspection.

The entropy-label command supports an orderly method for routers to signal entropy label capability (ELC) in the network. When enabled, the Cisco routers wait for the ELC signal from all downstream routers before passing their ELC to the next upstream routers in the chain. This eliminates the confusion that can occur when routers report their status randomly. If just one router in the chain does not support entropy label (EL), then the network will not use EL for load balancing. Random reporting could result in a lot of back and forth signaling before ELC is firmly established in the network.

Enable the add-el option on the ingress MPLS LDP router where the entropy label has to be added to the MPLS label stack. On the ingress router, use the show mpls ldp forwarding command to verify that the egress router has communicated its entropy label capability.

Examples

The following example shows how you can configure entropy label LDP signaling on transit LSR for load balancing.


RP/0/RP0RSP0/CPU0:router:hostname(config)# cef load-balancing fields mpls entropy-label
RP/0/RP0RSP0/CPU0:router:hostname(config)# mpls ldp
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# entropy-label
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# commit
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# end

This following example shows how to enable MPLS entropy label encapsulation on the ingress router.

Router(config)# mpls ldp entropy-label add-el
Router(config)# commit

explicit-null

To configure a router to advertise explicit null labels instead of implicit null labels, use the explicit-null command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

[vrf vrf-name] address-family {ipv4 | ipv6} label local advertise explicit-null [to peer-acl | for prefix-acl [to peer-acl]]

Syntax Description


vrf `vrf-name`	(Optional) Specifies the VRF name.
address-family ipv4	Specifies IP version 4 address family.
ipv6	Specifies IP version 6 address family.
label	Configures label control and policies.
local	Configures local label control and policies.
advertise	Configures outbound label advertisement control.
to `peer-acl`	(Optional) Specifies LDP peers for which explicit-null is advertised instead of implicit-null. Range is 1 to 99.
for `prefix-acl`	(Optional) Specifies prefixes for which explicit-null is advertised instead of implicit-null. Range is 1 to 99.

Command Default

Implicit null is advertised as default null label for routes, such as directly connected routes.

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.0	No modification.
Release 3.3.0	No modification.
Release 3.4.0	No modification.
Release 3.5.0	No modification.
Release 3.6.0	No modification.
Release 3.7.0	No modification.
Release 3.7.2	This command was introduced.
Release 3.8.0	No modification.
Release 3.9.0	No modification.
Release 5.0.0	This command was introduced.
Release 5.1.1	The vrf keyword was added. The adress-family ipv4 keyword was added. The label keyword was added. The local keyword was added. The advertise keyword was added.
Release 5.3.0	The ipv6 keyword was added.

Usage Guidelines

Normally, LDP advertises an implicit null label for directly connected routes. The implicit null label causes the previous hop router to perform next to last router hop popping.

The explicit-null command advertises the explicit-null labels in place of implicit null labels for directly connected prefixes.

LDP supports IPv4 standard access lists only.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following command shows how to advertise explicit null for all directly connected routes to all LDP peers:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# explicit-null

The following command sequence shows how to advertise explicit-null for directly connected route 192.168.0.0 to all LDP peers and implicit-null for all other directly connected routes:


RP/0/RP0RSP0/CPU0:router:hostname(config)# ipv4 access-list pfx_acl_192_168
RP/0/RP0RSP0/CPU0:router:hostname(config-ipv4-acl)# permit 192.168.0.0
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# explicit-null for pfx_acl_192_168

The following command sequence shows how to send explicit-null for all directly connected routes to peers 10.1.1.1 and 10.2.2.2 and implicit-null to all other peers:


RP/0/RP0RSP0/CPU0:router:hostname(config)# ipv4 access-list peer_acl_10
RP/0/RP0RSP0/CPU0:router:hostname(config-ipv4-acl)# permit 10.1.1.1
RP/0/RP0RSP0/CPU0:router:hostname(config-ipv4-acl)# permit 10.2.2.2
  
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# explicit-null to peer_acl_10

The following command shows how to advertise explicit-null for prefix 192.168.0.0 to peers 10.1.1.1 and 10.2.2.2 and advertise implicit-null for all other applicable routes to all other peers:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# explicit-null for pfx_acl_192_168 to peer_acl_10

Related Commands


Command	Description
show mpls ldp bindings	Displays the contents of LDP LIB.
show mpls ldp forwarding	Displays the contents of the LDP forwarding database.
show mpls ldp parameters	Displays current LDP parameter settings.

graceful-restart (MPLS LDP)

To configure graceful restart, use the graceful-restart command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

graceful-restart [reconnect-timeout seconds | forwarding-state-holdtime seconds]

Syntax Description


reconnect-timeout `seconds`	(Optional) Configures the time that the local LDP sends to its graceful restartable peer, indicating how long its neighbor should wait for reconnection in the event of a LDP session failure, in seconds. Range is 60 to 1800.
forwarding-state-holdtime `seconds`	(Optional) Configures the time the local forwarding state is preserved (without being reclaimed) after the local LDP control plane restarts, in seconds. Range is 60 to 1800.

Command Default

By default, graceful restart is disabled.

reconnect-timeout : 120

forwarding-state-holdtime : 180

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.0	No modification.
Release 3.3.0	No modification.
Release 3.4.0	No modification.
Release 3.5.0	No modification.
Release 3.6.0	No modification.
Release 3.7.0	No modification.
Release 3.7.2	This command was introduced.
Release 3.8.0	No modification.
Release 3.9.0	The maximum value for the seconds argument is 1800.

Usage Guidelines

Use the LDP graceful restart capability to achieve nonstop forwarding (NSF) during an LDP control plane communication failure or restart. To configure graceful restart between two peers, enable LDP graceful restart on both label switch routers (LSRs).

When an LDP graceful restart session is established and there is control plane failure, the peer LSR starts graceful restart procedures, initially keeps the forwarding state information pertaining to the restarting peer, and marks this state as stale. If the restarting peer does not reconnect within the reconnect timeout, the stale forwarding state is removed. If the restarting peer reconnects within the reconnect time period, it is provided recovery time to resynchronize with its peer. After this time, any unsynchronized state is removed.

The value of the forwarding state hold time keeps the forwarding plane state associated with the LDP control-plane in case of a control-plane restart or failure. If the control plane fails, the forwarding plane retains the LDP forwarding state for twice the forwarding state hold time. The value of the forwarding state hold time is also used to start the local LDP forwarding state hold timer after the LDP control plane restarts. When the LDP graceful restart sessions are renegotiated with its peers, the restarting LSR sends the remaining value of this timer as the recovery time to its peers. Upon local LDP restart with graceful restart enabled, LDP does not replay forwarding updates to MPLS forwarding until the forwarding state hold timer expires.

Note

In the presence of a peer relationship, any change to the LDP graceful restart configuration will restart LDP sessions. If LDP configuration changes from nongraceful restart to graceful restart, all the sessions are restarted. Only graceful restart sessions are restarted upon graceful restart to nongraceful restart configuration changes.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to configure an existing session for graceful restart:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# graceful-restart
  
RP/0/RP0RSP0/CPU0:router:hostname:Apr  3 10:56:05.392 : mpls_ldp[336]: %ROUTING-LDP-5-NBR_CHANGE : Nbr 172.16.0.1:0, DOWN 
RP/0/RP0RSP0/CPU0:router:hostname:Apr  3 10:56:05.392 : mpls_ldp[336]: %ROUTING-LDP-5-NBR_CHANGE : Nbr 192.168.0.1:0, DOWN 
RP/0/RP0RSP0/CPU0:router:hostname:Apr  3 10:56:09.525 : mpls_ldp[336]: %ROUTING-LDP-5-NBR_CHANGE : Nbr 192.168.0.1:0, UP 
RP/0/RP0RSP0/CPU0:router:hostname:Apr  3 10:56:11.114 : mpls_ldp[336]: %ROUTING-LDP-5-NBR_CHANGE : Nbr 172.16.0.1:0, UP 
  
RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp neighbor brief
  
  Peer              GR Up Time         Discovery Address
  ----------------- -- --------------- --------- -------
  192.168.0.1:0         Y  00:01:04                3       8
  172.16.0.1:0         N  00:01:02                2       5
  
RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp graceful-restart
  
    Forwarding State Hold timer : Not Running
    GR Neighbors                : 1
  
     Neighbor ID      Up  Connect Count  Liveness Timer      Recovery Timer    
     ---------------  --  -------------  ------------------  ------------------
     192.168.0.1          Y        1                -                   -

Related Commands


Command	Description
show mpls ldp forwarding	Displays the contents of the LDP forwarding database.
show mpls ldp graceful-restart	Displays information related to graceful restart.
show mpls ldp neighbor	Displays information about LDP neighbors.
show mpls ldp parameters	Displays current LDP parameter settings.
show mpls ldp summary	Displays summarized information regarding the LDP process.

session holdtime (MPLS LDP)

To change the time for which an Label Distribution Protocol (LDP) session is maintained in the absence of LDP messages from the session peer, use the session holdtime command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

session holdtime seconds

Syntax Description


`seconds`	Time, in seconds, that an LDP session is maintained in the absence of LDP messages from the session peer. Range is 15 to 65535.

Command Default

seconds : 180

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.0	No modification.
Release 3.3.0	No modification.
Release 3.4.0	No modification.
Release 3.5.0	No modification.
Release 3.6.0	No modification.
Release 3.7.0	No modification.
Release 3.7.2	This command was introduced.
Release 3.8.0	No modification.
Release 3.9.0	No modification.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to change the hold time of LDP sessions to 30 seconds:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# session holdtime 30

Related Commands


Command	Description
show mpls ldp parameters	Displays current LDP parameter settings.

hw-module label-allocation bvi-routes disable

To disable label allocation for prefixes whose next hop is over bridge-group virtual interface (BVI), use the hw-module label-allocation bvi-routes disable command in Admin Configuration modeSystem Admin Config mode. To enable label allocation over BVI, use the no form of this command.

hw-module label-allocation bvi-routes disable

This command has no keywords or arguments.

Command Default

Label allocation is enabled and LDP is configurable for BVI.

Command Modes

Admin Configuration modeSystem Admin Config mode

Command History


Release	Modification
Release 5.1.2	This command was introduced.

Usage Guidelines

Note

This configuration is required only when ASR 9000 Ethernet Line Cards are used as the MPLS-core facing cards. This configuration is not required on ASR 9000 Enhanced Ethernet Line Cards. MPLS LDP over BVI is not supported on ASR 9000 Ethernet Line Cards.

You need to unconfigure and reconfigure MPLS LDP for both the hw-module label-allocation bvi-routes disable and the no hw-module label-allocation bvi-routes disable configurations to take effect. The hw-module label-allocation bvi-routes disable configuration disables label allocation for BVI routes. The BVI routes should also be explicitly mentioned as static and dynamic. This configuration does not prevent labels being assigned to Recursive Static routes that point to the gateway on the BVI interface. Such recursive static routes have to be modified to include the BVI interface modifier to turn those into non-recursive routes.

When this configuration is committed, it will be present in the admin mode running configuration. However, labels already advertised need to be withdrawn by LDP. To withdraw the previously advertised routes, first unconfigure MPLS LDP and then reconfigure MPLS LDP (to advertise labels for non-BVI routes).

Note

The no hw-module label-allocation bvi-routes disable will not appear in the admin mode running configuration, once committed.

If LDP was enabled on BVI, it needs to be removed before unconfiguring/configuring MPLS LDP. Otherwise, LDP configuration will be rejected as the hw-module label-allocation bvi-routes disable configuration prevents LDP to be configured for BVI. When this command is configured, if the same route is reachable over ECMP paths and one of the paths is BVI, a label will not be allocated.

Task ID


Task ID	Operation
root-lr	read, write

Examples

This example shows how to disable label allocation for BVI routes:



RP/0/RP0RSP0/CPU0:router:hostname#admin
RP/0/RP0RSP0/CPU0:router:hostname(admin)#configure 
RP/0/RP0RSP0/CPU0:router:hostname(admin-config)#hw-module label-allocation bvi-routes disable

hw-module l3 feature mpls-over-udp-decap enable

To enable UDP decapsulation of UDP-encapsulated MPLS traffic on the ASR 9000 Series router, configure the hw-module l3 feature mpls-over-udp-decap enable command in Global Configuration modeXR Config mode. To return to the default behavior, use the no form of this command.

hw-module l3 feature mpls-over-udp-decap enable

This command has no keywords or arguments.

Command Default

UDP decapsulation function is disabled.

Command Modes

Global Configuration modeXR Config mode

Command History


Release	Modification
Release 7.0.1	This command was introduced.

Usage Guidelines

When you enable this command on a WAN edge ASR 9000 Series router, the UDP header is removed from UDP-encapsulated MPLS traffic. Based on the MPLS label, the traffic is forwarded towards the destination. If you don’t enable this function, the WAN edge router drops the UDP-encapsulated MPLS traffic it receives.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to configure UDP decapsulation function:


Router# configure
Router(config)# hw-module l3 feature mpls-over-udp-decap enable
Router(config)# commit

igp auto-config disable

To disable Label Distribution Protocol (LDP) auto-configuration, use the igp auto-config disable command in MPLS LDP interface configuration mode. To return to the default behavior, use the no form of this command.

igp auto-config disable

Syntax Description

This command has no arguments or keywords.

Command Default

No default behavior or values

Command Modes

MPLS LDP interface configuration

Command History


Release	Modification
Release 3.6.0	No modification.
Release 3.7.0	No modification.
Release 3.7.2	This command was introduced.
Release 3.8.0	No modification.
Release 3.9.0	No modification.

Usage Guidelines

IGP auto-configuration can be enabled on ISIS and OSPF. Configuration details are described in Cisco ASR 9000 Series Aggregation Services Router Routing Configuration Guide.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to disable LDP auto-configuration on POS 0/1/0/3:


RP/0/RP0RSP0/CPU0:router:hostname(config)# mpls ldp
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# interface pos 0/1/0/3
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp-if)# igp auto-config disable

Related Commands


Command	Description
show mpls ldp interface	Displays information about LDP-enabled interfaces.

igp sync delay

To enable Label Distribution Protocol (LDP) Interior Gateway Protocol (IGP) sync delay timer feature, use the igp sync delay command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

igp sync delay seconds

Syntax Description


`seconds`	Time, in seconds, that declaration of LDP sync state being up is delayed after session establishment upon link coming up. Range is 5 to 300.

Command Default

LDP does not delay declaration of sync up and notifies IGP as soon as sync up conditions are met for a link.

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.4.0	No modification.
Release 3.5.0	No modification.
Release 3.6.0	No modification.
Release 3.7.0	No modification.
Release 3.7.2	This command was introduced.
Release 3.8.0	No modification.
Release 3.9.0	No modification.

Usage Guidelines

By default, LDP declares LDP sync up as soon as all the requisite conditions are met, namely:
- LDP session is up.
- LDP has sent all its label bindings to at least one peer.
- LDP has received at least one label binding from a peer.
This minimizes traffic loss on link up but can still lead to substantial traffic loss under certain circumstances (for example, when interoperating with an LSR with ordered mode operation). It may be necessary to delay declaration of sync up after the session comes up by configuring a timeout period.
When the graceful-restart event is configured, the IGP sync delay timer does not take effect.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to configure LDP to delay declaration of sync-up to 30 seconds:


RP/0/RP0RSP0/CPU0:router:hostname# configure
RP/0/RP0RSP0/CPU0:router:hostname(config)# mpls ldp
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# igp sync delay 30

Related Commands


Command	Description
show mpls ldp igp sync	Displays LDP IGP sync information for link(s).

igp sync delay on-proc-restart

To delay the declaration of synchronization events to the Interior Gateway Protocol (IGP) when the label distribution protocol (LDP) fails or restarts, use the igp sync delay on-proc restart command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

igp sync delay on-proc restart seconds

Syntax Description


`seconds`	Time, in seconds, duration of process-level delay for synchronization events when the LDP fails or restarts. Range is from 60 to 600.

Command Default

This command is disabled by default.

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.9.0	This command was introduced.
Release 3.9.0	No modification.

Usage Guidelines

The igp sync delay on-proc restart command enables a process-level delay for synchronization events when the LDP fails or restarts. This delay defers the sending of sync-up events to the IGP until most or all the LDP sessions converge and also allows the LDP to stabilize. This allows the LDP process failure to be less stressful because IGPs receive all the sync-up events in bulk. This means that the IGP is required to run the shortest path first (SPF) and link-state advertisements (LSAs) only one time with an overall view of the sync-up events.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to configure LDP to delay the declaration of synchronization events to IGP by 60 seconds:


RP/0/RP0RSP0/CPU0:router:hostname# configure
RP/0/RP0RSP0/CPU0:router:hostname(config)# mpls ldp
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# igp sync delay on-proc restart 60

The following example shows the status following execution of the command:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp igp sync
  
  Process Restart Sync Delay: 60 sec, Gloal timer running (15 sec remaining)
  GigabitEthernet0/3/0/2:
  Sync status: Deferred
  ….

When the timer is not running, the output displays the following:

Process Restart Sync Delay: 60 sec, Global timer not running

Related Commands


Command	Description
show mpls ldp igp sync	Displays LDP IGP sync information for link(s).

implicit-null-override

To configure a router to advertise implicit null labels to a set of prefixes, for which a non-null label is to be advertised by default, use the implicit-null-override command in MPLS LDP label configuration mode. To return to the default behavior, use the no form of this command.

[vrf vrf-name] address-family {ipv4 | ipv6} label local implicit-null-override {for prefix-acl}

Syntax Description

vrf vrf-name

(Optional) Specifies the VRF name.

address-family ipv4

Specifies IP version 4 address family.

ipv6

Specifies IP version 6 address family.

label

Configure label control and policies.

local

Configure local label control and policies.

for prefix-acl

Specifies the usage of implicit-null label to a set of prefixes. Range is 1 to 99.

Note

This command works with any prefix including static, IGP, and BGP, when specified in the ACL.

Command Default

Implicit null is advertised as default null label for routes, such as directly connected routes, whereas a non-null label is advertised for IGP, BGP, and static prefixes.

Command Modes

MPLS LDP label configuration

Command History


Release	Modification
Release 4.2.1	This command was introduced.
Release 5.1.1	The following items were added: The vrf keyword was added. The adress-family ipv4 keyword was added. The label keyword was added. The local keyword was added.
Release 5.3.0	The ipv6 keyword was added.

Task ID


Task ID	Operation
mpls-ldp	read, write

Examples

The following command shows how to advertise implicit-null label to a specific LDP peer:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# implicit-null-override for 80

interface (MPLS LDP)

To configure or enable Multiprotocol Label Switching (MPLS) Label Distribution Protocol (LDP) on an interface, use the interface command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

interface type interface-path-id

Syntax Description

type

Interface type. For more information, use the question mark (?) online help function.

interface-path-id

Physical interface or a virtual interface.

Note

Use the show interfaces command to see a list of all possible interfaces currently configured on the router.

For more information about the syntax for the router, use the question mark (?) online help function.

Command Default

No default behavior or values

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.0	No modification.
Release 3.3.0	No modification.
Release 3.4.0	No modification.
Release 3.5.0	No modification.
Release 3.6.0	No modification.
Release 3.7.0	No modification.
Release 3.8.0	No modification.
Release 3.9.0	This command was introduced.
Release 5.1	The Bridge-Group Virtual Interface (BVI) configuration was added to support MPLS LDP over Integrated Routing and Bridging (IRB).

Usage Guidelines

When you configure LDP on an interface, the LDP process begins neighbor discovery, sending link hello messages on the interface. This can result in a session setup with discovered neighbors. When LDP is enabled on tunnel-te interfaces, targeted discovery procedures apply.

LDP interface configuration supports forward reference; accordingly, it is possible to configure a nonexisting interface under LDP.

Note

You cannot enable LDP on loopback interfaces.

MPLS LDP is supported over Generic Route Encapsulation (GRE) tunnels by configuring the tunnel-ip interface. LDP establishes a link session (as opposed to a targeted LDP session) over the GRE tunnel.

MPLS LDP is supported over Integrated Routing and Bridging (IRB) by enabling the Bridge-Group Virtual Interface (BVI) configuration. Just like the physical interface, MPLS LDP discovers LDP neighbors on the bridge domain represented by the BVI. With the BVI configuration, LDP session is established with potential peers and the labeled packets are switched (impose, dispose, and, label-switched).

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to configure LDP on POS interface 0/1/0/0:


RP/0/RP0RSP0/CPU0:router:hostname# configure
RP/0/RP0RSP0/CPU0:router:hostname(config)# mpls ldp
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# interface POS 0/1/0/0
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp-if)#

The following example shows how to configure LDP on an MPLS TE tunnel:


RP/0/RP0RSP0/CPU0:router:hostname# configure
RP/0/RP0RSP0/CPU0:router:hostname(config)# mpls ldp
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# interface tunnel-te 123
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp-if)#

This example shows how to configure MPLS LDP over BVI interfaces:


RP/0/RP0RSP0/CPU0:router:hostname#configure 
RP/0/RP0RSP0/CPU0:router:hostname(config)#mpls ldp 
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)#interface BVI 65535
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp-if)#

Related Commands


Command	Description
show mpls ldp parameters	Displays current LDP parameter settings.
show mpls ldp neighbor	Displays LDP neighbor session parameters.

l2vpn neighbor all ldp flap

To flap the LDP sessions in order to enable interoperability with the peer router which does not support label request, use the l2vpn neighbor all ldp flap command in Global Configuration modeXR Config mode.

To return to the default behavior, use the no form of this command.

l2vpn neighbor all ldp flap

Syntax Description

This command has no arguments or keywords.

Command Default

None

Command Modes

Global Configuration modeXR Config mode

Command History


Release	Modification
Release 4.3.4	This command was introduced.

Usage Guidelines

Configuring the l2vpn neighbor all ldp flap command flaps all the LDP sessions when a route processor fail over (RPFO) occurs.

Task ID


Task ID	Operation
l2vpn	read, write

Examples

The following example shows how to flap the LDP sessions:

RP/0/RP0RSP0/CPU0:router:hostname#config
RP/0/RP0RSP0/CPU0:router:hostname#l2vpn neighbor all ldp flap
RP/0/RP0RSP0/CPU0:router:hostname#commit

label accept

To control the receipt of labels (remote bindings) for a set of prefixes from a peer, use the label accept command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

label accept for prefix-acl from ip-address

Syntax Description


for `prefix-acl`	Accepts and retains remote bindings for prefixes that are permitted by the prefix access list prefix-acl argument.
from `ip-address`	Displays the peer IP address.

Command Default

LDP accepts and retains label bindings for all prefixes from all peers.

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.4.0	No modification.
Release 3.5.0	No modification.
Release 3.6.0	No modification.
Release 3.7.0	No modification.
Release 3.7.2	This command was introduced.
Release 3.8.0	No modification.
Release 3.9.0	No modification.

Usage Guidelines

By default, LDP accepts labels (as remote bindings) for all prefixes from all its peers. To save resources (such as memory) configure the access list to specify label and binding acceptance for a set of prefixes from a peer.

If the inbound label filtering policy changes such that it now allows previously denied prefixes from a peer, you must reset the LDP session with the peer using the clear mpls ldp neighbor command.

LDP supports IPv4 standard access lists only.

Note

Label acceptance control is also referred to as LDP inbound label filtering.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to configure inbound label filtering policy. In this example, an LSR is configured to accept and retain label bindings for prefixes 192.168.1.1 (pfx_acl_1) from peer 10.0.0.1, prefix 192.168.2.2 (pfx_acl_2) from peer 172.16.0.1, and prefixes 192.168.1.1, 192.168.2.2, 192.168.3.3 (pfx_acl_3) from peer 209.165.201.1:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# label accept
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp-lbl-acpt)# for pfx_acl_1 from 10.0.0.1
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp-lbl-acpt)# for pfx_acl_2 from 172.16.0.1
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp-lbl-acpt)# for pfx_acl_3 from 209.165.201.1

Related Commands


Command	Description
label advertise	Controls advertisement of LDP local label bindings (outbound label filtering).
show mpls ldp bindings	Displays LDP binding information.

label advertise

To control the advertisement of local labels, use the label advertise command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

label advertise [disable | for prefix-acl [to peer-acl] | interface type interface-path-id]

Syntax Description

disable

(Optional) Disables label advertisement to all peers for all prefixes.

for prefix-acl

(Optional) Specifies prefix destinations for which labels will be advertised.

to peer-acl

(Optional) Specifies which LDP neighbors will receive label advertisements.

interface

(Optional) Specifies an interface for label allocation and advertisement of its interface IP address.

type

Interface type. For more information, use the question mark (?) online help function.

interface-path-id

Physical interface or a virtual interface.

Note

Use the show interfaces command to see a list of all possible interfaces currently configured on the router.

For more information about the syntax for the router, use the question mark (?) online help function.

Command Default

LDP advertises labels for all known prefixes to all peers. LDP does not advertise labels for local interfaces addresses other than Loopback interfaces.

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.3.0	No modification.
Release 3.4.0	No modification.
Release 3.5.0	No modification.
Release 3.6.0	No modification.
Release 3.7.0	No modification.
Release 3.7.2	This command was introduced.
Release 3.8.0	No modification.
Release 3.9.0	No modification.

Usage Guidelines

The label advertise command determines how the label switch router (LSR) advertises local labels. The following rules describe the effects of running multiple commands:

Every command has a prefix-acl or peer-acl pair associated with it, as follows:
- In the absence of the for or to keywords, the access list pair is (none, none).
- When using the for keyword without the to keyword, the access list is (prefix-acl, none).
A prefix can have a maximum of one (prefix-acl, peer-acl) pair, as follows:
- A (prefix-acl, peer-acl) pair applies to a prefix only if the prefix-acl matches the prefix. A match occurs if the prefix-acl permits the prefix.
- If more than one (prefix-acl, peer-acl) pair from multiple label advertise commands matches a prefix, the (prefix-acl, peer-acl) pair in the first command applies to the prefix. The order in which the label advertise commands are processed is sorted based on the ACL names in a MIB-lexicographical way (shorter ACL name length will be processed first, if two ACLs are of equal length, then dictionary ordering is used).

When an LSR is ready to advertise a label for a prefix, the LSR determines whether a (prefix-acl, peer-acl) pair applies to the prefix.

If none applies, and if the disable keyword has been configured for the command, the label for the prefix is not advertised to any peer; otherwise, the label is advertised to all peers.
If a (prefix-acl, peer-acl) pair applies to the prefix, and if the prefix-acl denies the prefix, the label is not advertised to the peers defined in the peer-acl. Nevertheless, the prefix may be matched in subsequent (prefix-acl, peer-acl) entries and advertised to other peers.
If (prefix-acl, peer-acl) pair applies to the prefix and if the prefix-acl denies the prefix, the label is not advertised to peers defined in the peer-acl. Nevertheless, the prefix may be matched in subsequent (prefix-acl, peer-acl) entries and advertised to other peers.
If the prefix-acl permits the prefix and there is a peer-acl, the label is advertised to all peers permitted by the peer-acl.

Normally, LDP advertises labels for non-BGP routes present in the routing table. Additionally, LDP advertises labels from /32 IP addresses on Loopback interfaces and does not advertise /32 addresses for other non-Loopback interfaces. To control advertisement of labels for /32 IP addresses on these interfaces, use the label advertise interface command.

LDP supports IPv4 standard access lists only.

Note

Label advertisement control is also referred to as LDP outbound label filtering.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to disable advertisement of all locally assigned labels to all peers:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# label advertise
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp-lbl-advt)# disable

The following example shows how to send labels only for prefixes 10.1.1.0 and 20.1.1.0 to all peers:


RP/0/RP0RSP0/CPU0:router:hostname(config)# ipv4 access-list pfx_acl_1
RP/0/RP0RSP0/CPU0:router:hostname(config-ipv4-acl)# permit 10.1.1.0
RP/0/RP0RSP0/CPU0:router:hostname(config-ipv4-acl)# permit 20.1.1.0

RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# label advertise
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp-lbl-advt)# disable
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp-lbl-advt)# for pfx_acl_1

The following example shows how to send labels for prefix 10.0.0.0 to peers 10.1.1.1 and 10.2.2.2, labels for prefix 20.0.0.0 to peer 20.1.1.1, and labels for all other prefixes to all other peers:


RP/0/RP0RSP0/CPU0:router:hostname(config)# ipv4 access-list pfx_acl_10
RP/0/RP0RSP0/CPU0:router:hostname(config-ipv4-acl)# permit 10.0.0.0
  
RP/0/RP0RSP0/CPU0:router:hostname(config)# ipv4 access-list pfx_acl_20
RP/0/RP0RSP0/CPU0:router:hostname(config-ipv4-acl)# permit 20.0.0.0
  
RP/0/RP0RSP0/CPU0:router:hostname(config)# ipv4 access-list peer_acl_10
RP/0/RP0RSP0/CPU0:router:hostname(config-ipv4-acl)# permit 10.1.1.1
RP/0/RP0RSP0/CPU0:router:hostname(config-ipv4-acl)# permit 10.2.2.2
  
RP/0/RP0RSP0/CPU0:router:hostname(config)# ipv4 access-list peer_acl_20
RP/0/RP0RSP0/CPU0:router:hostname(config-ipv4-acl)# permit 20.1.1.1 
  
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# label advertise
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp-lbl-advt)# for pfx_acl_10 to peer_acl_10
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp-lbl-advt)# for pfx_acl_20 to peer_acl_20

Note

To advertise pfx_acl_10 to peer_acl_10 and pfx_acl_20 to peer_acl_20 and disable all other advertisements to all other peers, include the disable keyword with the label advertise command.

The following example shows how to use the interface keyword to advertise /32 IP address for POS 0/1/0/0:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# label advertise
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp-lbl-advt)# interface POS 0/1/0/0

Related Commands


Command	Description
show mpls ldp neighbor	Displays information about LDP neighbors.
show mpls ldp bindings	Displays information about LDP label bindings.

label allocate

To control allocation of local label only for a set of prefixes, use the label allocate command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

label allocate for {prefix-acl | host-routes}

Syntax Description


for	Specifies set of prefixes for which local label needs to be allocated.
`prefix-acl`	IP access-list name or number. Range is from 1 to 99.
host-routes	Allocates the label for host routes only.

Command Default

LDP allocates local label for all learned routes (prefixes).

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.4.0	No modification.
Release 3.5.0	No modification.
Release 3.6.0	No modification.
Release 3.7.0	No modification.
Release 3.7.2	This command was introduced.
Release 3.8.0	No modification.
Release 3.9.0	The host-routes keyword was added.

Usage Guidelines

Local label allocation control lets you override the default label allocation policy and provides many benefits, including reduced memory usage and fewer forwarding and network updates.

By default, LDP allocates local labels for all learned routes. There are times when you may want to limit label allocation for a given set of prefixes; for example, when using LDP in the core network to provide MPLS transport from one edge to another edge. In such cases, it is necessary to set up label switch packets (LSPs) for Loopback /32 addresses for provider edge (PE) routers (rendering it unnecessary to allocate and advertise local labels for other Interior Gateway Protocol (IGP) prefixes).

LDP supports IPv4 standard access lists only.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to configure LDP to limit allocation of local labels to prefixes 192.168.1.1, 192.168.2.2, and 192.168.3.3 only:


RP/0/RP0RSP0/CPU0:router:hostname(config)# ipv4 access-list pfx_acl_1
RP/0/RP0RSP0/CPU0:router:hostname(config-ipv4-acl)# permit 192.168.1.1
RP/0/RP0RSP0/CPU0:router:hostname(config-ipv4-acl)# permit 192.168.2.2
RP/0/RP0RSP0/CPU0:router:hostname(config-ipv4-acl)# permit 192.168.3.3
  
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# label allocate for pfx_acl_1

Related Commands


Command	Description
show mpls ldp bindings	Displays information about LDP label bindings.
show mpls ldp forwarding	Displays the contents of the LDP forwarding database.

log graceful-restart

To set up notification describing graceful-restart (GR) session events, use the log graceful-restart command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

log graceful-restart

Syntax Description

This command has no arguments or keywords.

Command Default

No default behavior or values

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.4.0	No modification.
Release 3.5.0	No modification.
Release 3.6.0	No modification.
Release 3.7.0	No modification.
Release 3.7.2	This command was introduced.
Release 3.8.0	No modification.
Release 3.9.0	No modification.

Usage Guidelines

Use the log graceful-restart command to receive a syslog/console message when a graceful restart-related session event occurs, including LDP graceful restart session disconnection, reconnection, and timeout.

Note

A logging message is issued upon graceful restart session events.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to enable logging messages for graceful restart session events:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# log graceful-restart

The following sample output shows the logging events that can be displayed on the console:


RP/0/RP0RSP0/CPU0:router:hostname: mpls_ldp[340]: %ROUTING-LDP-5-GR : GR session 4.4.4.4:0 (instance 1) disconnected 
  
RP/0/RP0RSP0/CPU0:router:hostname: mpls_ldp[340]: %ROUTING-LDP-5-GR : GR session 4.4.4.4:0 (instance 2) reconnected 
  
RP/0/RP0RSP0/CPU0:router:hostname: mpls_ldp[340]: %ROUTING-LDP-5-GR : GR session 5.5.5.5:0 (instance 3) timed out
  
RP/0/RP0RSP0/CPU0:router:hostname: mpls_ldp[336]: %ROUTING-LDP-5-GR_RESTART_COMPLETE : GR forwarding state hold timer has expired

Related Commands


Command	Description
show mpls ldp neighbor	Displays information about LDP neighbors.
show mpls ldp graceful-restart	Displays information about LDP GR sessions.

log neighbor

To enable logging of notices describing session changes, use the log neighbor command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

log neighbor

Syntax Description

This command has no arguments or keywords.

Command Default

No default behavior or values

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.0	No modification.
Release 3.4.0	No modification.
Release 3.5.0	No modification.
Release 3.6.0	No modification.
Release 3.7.0	No modification.
Release 3.7.2	This command was introduced.
Release 3.8.0	No modification.
Release 3.9.0	No modification.

Usage Guidelines

Use the log neighbor command to receive a syslog or console message when a neighbor goes up or down.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to enable logging messages for neighbor session up and down events:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# log neighbor

Note

A logging message is issued when an LDP session state changes from up to down (and down to up).

The following shows sample output of logging events that can be displayed on the console:


RP/0/RP0RSP0/CPU0:router:hostname:10 21:11:32.111:mpls_ldp[113]:%LDP-5-NBR_CHANGE: Nbr 10.44.44.44:0, DOWN

Related Commands


Command	Description
show mpls ldp neighbor	Displays information about LDP neighbors.

log nsr

To enable logging of nonstop routing (NSR) synchronization events, use the log nsr command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

log nsr

Syntax Description

This command has no arguments or keywords.

Command Default

No default behavior or values

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.7.0	No modification.
Release 3.7.2	This command was introduced.
Release 3.8.0	No modification.
Release 3.9.0	No modification.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to enable logging of NSR synchronization events:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# log nsr

log session-protection

To enable logging of notices describing LDP session protection events, use the log session-protection command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

log session-protection

Syntax Description

This command has no arguments or keywords.

Command Default

No default behavior or values

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.4.0	No modification.
Release 3.5.0	No modification.
Release 3.6.0	No modification.
Release 3.7.0	No modification.
Release 3.7.2	This command was introduced.
Release 3.8.0	No modification.
Release 3.9.0	No modification.

Usage Guidelines

Use the log session-protection command to receive a syslog or console message when LDP session protection event occurs. These events include LDP session protection initiation, recovery, and timeout.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to enable logging messages for session protection events:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# log session-protection

Note

Logging messages are issued when session protection events occur.

The following sample output shows the logging events that are displayed on the console:


RP/0/RP0RSP0/CPU0:router:hostname:Apr 21 12:15:01.742: mpls_ldp[315]:%ROUTING-LDP-5-SESSION_PROTECTION: Session hold up initiated for peer 4.4.4.4:0
  
RP/0/RP0RSP0/CPU0:router:hostname:Apr 21 12:18:04.987: mpls_ldp[315]:%ROUTING-LDP-5-SESSION_PROTECTION: Session recovery succeeded for peer 4.4.4.4:0

Related Commands


Command	Description
show mpls ldp neighbor	Displays information about LDP neighbors.

make-before-break

To enable Multicast Label Distribution Protocol (MLDP) make-before-break (MBB) support, use make-before-break command in MPLS LDP MLDP configuration.

address-family ipv4 make-before-break [delay seconds | route-policy name]

Syntax Description


delay `seconds`	(Optional) Specifies the MBB forwarding delay in seconds. Range is 0 to 600.
route-policy `name`	(Optional) Specifies the route policy name.

Command Default

No default behavior or values

Command Modes

MPLS LDP MLDP configuration

Command History


Release	Modification
Release 5.1.1	This command was introduced.

Task ID


Task ID	Operation
mpls-ldp	read, write

Examples

The following example shows how to enable MLDP MBB support:



RP/0/RP0RSP0/CPU0:router:hostname(config-ldp-mldp)# address-family ipv4 make-before-break

mldp disable

To disable Multicast Label Distribution Protocol (MLDP) on Label Distribution Protocol (LDP) enabled interfaces, use mldp disable command in MPLS LDP configuration mode.

interface type interface-path-id address-family {ipv4 | ipv6} igp mldp disable

Syntax Description

interface type

Interface type. For more information, use the question mark (?) online help function.

interface-path-id

Physical interface or a virtual interface.

Note

Use the show interfaces command to see a list of all possible interfaces currently configured on the router.

For more information about the syntax for the router, use the question mark (?) online help function.

Command Default

No default behavior or values

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 5.1.1	This command was introduced.

Task ID


Task ID	Operation
mpls-ldp	read

Examples

The following example shows how to disable MLDP on a LDP enabled interface:



RP/0/RP0RSP0/CPU0:router:hostname(config-ldp-if-af)# igp mldp disable

mldp logging notifications

To enable Multicast Label Distribution Protocol (MLDP) system log notifications, use the mldp logging notifications command in MPLS LDP MLDP configuration mode. To disable this function, use the no form of this command.

mldp logging notifications

Syntax Description

This command has no arguments or keywords.

Command Default

No default behavior or values

Command Modes

MPLS LDP MLDP configuration

Command History


Release	Modification
Release 5.1.1	This command was introduced.

Task ID


Task ID	Operation
mpls-ldp	read

Examples

The following example shows how to enable MLDP system log notifications:



RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# mldp logging notifications

mofrr (MPLS-LDP)

To enable Multicast Label Distribution Protocol (MLDP) multicast only fast reroute (MoFRR) support, use mofrr command in MPLS LDP MLDP configuration.

address-family ipv4 mofrr [route-policy name]

Syntax Description


route-policy `name`	(Optional) Specifies the route policy name.

Command Default

No default behavior or values

Command Modes

MPLS LDP MLDP configuration

Command History


Release	Modification
Release 5.1.1	This command was introduced.

Task ID


Task ID	Operation
mpls-ldp	read

Examples

The following example shows how to enable MLDP MoFRR support:



RP/0/RP0RSP0/CPU0:router:hostname(config-ldp-mldp)# address-family ipv4 mofrr

mpls ldp

To enter MPLS Label Distribution Protocol (LDP) configuration mode, use the mpls ldp command in Global Configuration modeXR Config mode.

mpls ldp

Syntax Description

This command has no arguments or keywords.

Command Default

No default behavior or values

Command Modes

Global Configuration modeXR Config mode

Command History


Release	Modification
Release 3.9.0	This command was introduced.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to MPLS LDP configuration mode:


RP/0/RP0RSP0/CPU0:router:hostname# configure
RP/0/RP0RSP0/CPU0:router:hostname(config)# mpls ldp
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)

mpls lsd app-reg-delay disable

Allows LDP to allocate labels with out any delay if segment routing will not be configured. By default, MPLS Label Switching Database (LSD) waits for segment routing enabled IGPs to allocate labels first because of their global significance. LSD allows LDP to allocate labels only after segment routing enabled IGPs complete label allocation. If segment routing will not be configured, this leads to additional delay and may cause traffic drops after router reload. This command avoids the delay in label allocation.

mpls lsd app-reg-delay disable

This command has no arguments or keywords.

Command Default:

No default behavior or values

Command Modes:

Global Configuration modeXR Config mode


Release	Modification
Release 5.3.3	This command was introduced.

Usage Guidelines

No specific guidelines impact the use of this command.


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to configure mpls lsd app-reg-delay disable command:

RP/0/RSP0/CPU0:router# configure
RP/0/RSP0/CPU0:router(config)# mpls lsd app-reg-delay disable

neighbor dual-stack tlv-compliance

To configure dual-stack TLV compliance check, use the neighbor dual-stack tlv-compliance command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

neighbor dual-stack tlv-compliance

no neighbor dual-stack tlv-compliance

Syntax Description

This command has no arguments or keywords.

Command Default

Compliance check is disabled by default.

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 6.0	This command was introduced.

Usage Guidelines

No specific guidelines impact the use of this command.

Task ID


Task ID	Operation
mpls-ldp	read, write

Examples

The following example shows how to configure dual-stack TLV compliance check:


RP/0/RP0RSP0/CPU0:router:hostname# configure
RP/0/RP0RSP0/CPU0:router:hostname(config)# mpls ldp
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# neighbor dual-stack tlv-compliance

neighbor dual-stack transport-connection max-wait

To configure the maximum time (in seconds) the preferred address family connection must wait to establish before resorting to non-preferred address family or FCFS, use the neighbor dual-stack transport-connection max-wait command in MPLS LDP configuration mode.

neighbor dual-stack transport-connection max-wait seconds

Syntax Description


`seconds`	Specifies the maximum wait time in seconds for preferred transport connection establishment. The range is from 0 to 60. Zero indicates no preference.

Command Default

No default behavior or values

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 5.3.0	This command was introduced.

Task ID


Task ID	Operation
mpls ldp	read, write

Examples

The following example shows how to configure the maximum wait time for preferred transport connection establishment:


RP/0/0/CPU0:ios#configure
RP/0/0/CPU0:ios(config)#mpls ldp
RP/0/0/CPU0:ios(config-ldp)#neighbor dual-stack transport-connection max-wait 5

neighbor dual-stack transport-connection prefer ipv4 for-peers

To configure preferred transport as IPv4 for set of peers to establish TCP connection in a dual-stack setup, use the neighbor dual-stack transport-connection prefer ipv4 for-peers command in the MPLS LDP configuration mode.

neighbor dual-stack transport-connection prefer ipv4 for-peers access-list

Syntax Description


`access-list`	IPv4 access-list (specifies peer LSR IDs in A.B.C.D format).

Command Default

No default behavior or values

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 5.3.0	This command was introduced.

Task ID


Task ID	Operation
mpls ldp	read, write

Examples

The following example shows how to configure preferred transport as IPv4 for set of peers:


RP/0/0/CPU0:ios#configure
RP/0/0/CPU0:ios(config)#mpls ldp
RP/0/0/CPU0:ios(config-ldp)#neighbor dual-stack transport-connection prefer ipv4 for-peers 3.3.3.3

neighbor password

To configure password authentication using the TCP Message Digest 5 (MD5) option for a neighbor, use the neighbor password command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

[vrf vrf-name] neighbor ldp-id password {clear | disable | encrypted} password

no [vrf vrf-name] neighbor ldp-id password

Syntax Description


`ldp-id`	LDP ID of neighbor in A.B.C.D:0 format.
clear	Clears the password for the encyrption parameter to specify that an unencrypted password will follow.
encrypted	Specifies that an encrypted password will follow.
`password`	(Clear text) Encrypted or unencrypted password string.

Command Default

LDP sessions are negotiated without any password (and MD5).

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.7.2	This command was introduced.

Usage Guidelines

This security feature is enabled per neighbor, so that a session establishment attempt is allowed only when a password match has been configured. This option must be configured so that both peer passwords match.

To override the default password for a specific neighbor, use the neighbor ldp-id password command, where the ldp-id argument is the LDP ID of the neighbor.

Note

The global default password must be configured before being able to override the default password for a specific neighbor.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to configure the password abc for neighbor 10.20.20.20:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# neighbor 10.20.20.20:0 password clear abc

Related Commands


Command	Description
neighbor targeted	Configures transmission of targeted hellos towards a neighbor.

neighbor password disable

To override an individual neighbor which requires no password, use the neighbor password disable command in MPLS LDP configuration mode.

neighbor IP-address password disable

Syntax Description


`IP-address`	Neighbor IP address.

Command Default

LDP sessions are negotiated without any password (and MD5).

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.7.2	This command was introduced.

Usage Guidelines

The system uses the global password to compute each neighbor's effective password and overrides the global password with the individual neighbor password, if configured. The session remains stable if you shift from an individual neighbor password to an equal global password. However, if the effective password changes during configuration, the session might be rendered unstable.

Note

You must configure the password for an individual neighbor using the neighbor’s LSR ID.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to override the individual password abc, for the neighbor:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# neighbor 10.20.20.20 password disable abc
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)#

neighbor targeted

To configure transmission of targeted hellos toward a neighbor for setting up an LDP session, use the neighbor targeted command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

address-family {} neighbor IP address targeted

no address-family {} neighbor IP address targeted

Syntax Description


`IP address`	Neighbor IP address.

Command Default

No default behavior or values

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.7.2	This command was introduced.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to set up a targeted discovery session for neighbor 200.1.1.1:


RP/0/RSP0/CPU0:router(config-ldp)# neighbor 200.1.1.1 targeted

Related Commands


Command	Description
neighbor password	Configures password authentication using MD5.
show mpls ldp neighbor	Displays information about LDP neighbors.
show mpls ldp discovery	Displays information about LDP discovery sources.

nsr (MPLS-LDP)

To configure nonstop routing for LDP protocols in the event of a disruption in service, use the nsr command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

nsr

no nsr

Syntax Description

This command has no arguments or keywords.

Command Default

By default, MPLS LDP NSR is disabled.

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.7.2	This command was introduced.

Usage Guidelines

A disruption in service may include any of the following events:

Route Switch Processor (RSP) switchover
LDP process restart
In-service system upgrade (ISSU)
Minimum disruption restart (MDR)

Enabling NSR causes events such as these to be invisible to the routing peers and provide minimal service disruption.

Note

The LDP Process restart is supported by NSR only if the NSR process-failures switchover is configured, else the process restart causes the session to be unstable.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to enable MPLS LDP NSR:


RP/0/RP0RSP0/CPU0:router:hostname# configure
RP/0/RP0RSP0/CPU0:router:hostname(config)# mpls ldp
RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# nsr

Related Commands


Command	Description
nsr process-failures switchover	Configures switchover as a recovery action for active instances to switch over to a standby RP or a DRP, to maintain NSR. For more information, see Cisco ASR 9000 Series Aggregation Services Router IP Addresses and Services Command Reference .
show mpls ldp neighbor	Displays standby node specific information.

recursive-fec

To enable Multicast Label Distribution Protocol (MLDP) recursive-fec support, use recursive-fec command in MPLS LDP MLDP configuration.

address-family ipv4 recursive-fec [route-policy name]

Syntax Description


route-policy `name`	(Optional) Specifies the route policy name.

Command Default

No default behavior or values

Command Modes

MPLS LDP MLDP configuration

Command History


Release	Modification
Release 6.0	This command was introduced.

Usage Guidelines

No specific guidelines impact the use of this command.

Task ID


Task ID	Operation
mpls-ldp	read

Examples

The following example shows how to enable MLDP recursive fec support:



RP/0/RP0RSP0/CPU0:router:hostname(config-ldp-mldp)# address-family ipv4 recursive-fec

router-id (MPLS LDP)

To specify an IPv4 address to act as the router ID, use the router-id command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

router-id lsr-id

no router-id

Syntax Description


`lsr-id`	LSR ID in A.B.C.D format.

Command Default

LDP uses router ID as determined by global router ID agent, IP Address Repository Manager (IP ARM).

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.7.2	This command was introduced.

Usage Guidelines

LDP uses the router ID from different sources in the following order:

Configured LDP router ID.
Global router ID (if configured).
Calculated (computed) using the primary IPv4 address of the highest numbered configured loopback address. We recommend configuring at least one loopback address.

Note

We recommend that you configure an IP address for the LDP router-id to avoid unnecessary session flaps.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to specify an LSR ID as the router ID:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)#router-id 10.0.0.1

Related Commands


Command	Description
show mpls ldp discovery	Displays the status of the LDP discovery process.
show mpls ldp neighbor	Displays information about LDP neighbors.
show mpls ldp parameters	Displays current LDP parameter settings.

router ospf

To enable Open Shortest Path First (OSPF) LDP IGP synchronization for a specific VRF or a specific VRF area or a specific VRF area interface, use the router ospf command in Global Configuration modeXR Config mode.

router ospf process-id [vrf vrf-name [area {area-id | ip-address}] [interface type interface-path-id] mpls ldp sync [disable]]

Syntax Description

process-id

Internally used identification parameter for an OSPF routing process. It is locally assigned and can be any positive integer. A unique value is assigned for each OSPF routing process.

vrf vrf-name

(Optional) Specifies the name of the VRF instance to associate with OSPF VRF processes.

area

(Optional) Enters the OSPF area configuration submode.

area-id

Specifies the OSPF area ID as a decimal value.

ip-address

Specifies the OSPF area ID as an IP address in A.B.C.D format.

interface

(Optional) Enters the OSPF interface configuration submode.

type

Interface type. For more information, use the question mark (?) online help function.

interface-path-id

Physical interface or a virtual interface.

Note

Use the show interfaces command to see a list of all possible interfaces currently configured on the router.

For more information about the syntax for the router, use the question mark (?) online help function.

sync

Enables LDP IGP synchronization on the specified interface.

disable

(Optional) Disables MPLS LDP synchronization.

Command Default

No default behavior or values

Command Modes

Global Configuration modeXR Config mode

Command History


Release	Modification
Release 5.1.1	This command was introduced.

Task ID


Task ID	Operation
mpls-ldp	read, write

Examples

The following example shows how to enable OSPF LDP IGP synchronization for a specific VRF:



RP/0/RP0RSP0/CPU0:router:hostname# configure
RP/0/RP0RSP0/CPU0:router:hostname(config)#router ospf 109
RP/0/RP0RSP0/CPU0:router:hostname(config-ospf)#

session protection

To enable the LDP session protection feature for keeping LDP peer session up by means of targeted discovery following the loss of link discovery with a peer, use the session protection command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

session protection [duration seconds | infinite] [for peer-acl]

no session protection

Syntax Description


duration `seconds`	(Optional) Specifies the protection duration, that is, the number of seconds that targeted discovery should continue following the loss of link discovery to a neighbor. Range is 30 to 2147483.
infinite	(Optional) Specifies session protection to last forever after loss of link discovery.
for `peer-acl`	(Optional) Specifies set of LDP peers for which session protection is to be enabled.

Command Default

By default, session protection is disabled. When enabled without peer-acl and duration, session protection is provided for all LDP peers and continues for 24 hours after a link discovery loss.

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.7.2	This command was introduced.

Usage Guidelines

LDP session protection feature allows you to enable the automatic setup of targeted hello adjacencies with all or a set of peers and specify the duration for which session needs to be maintained using targeted hellos after loss of link discovery.

LDP supports only IPv4 standard access lists.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to enable session protection for all discovered peers with unlimited duration to maintain the session after link discovery loss:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# session protection

The following example shows how to enable session protection for a set of peers (as permitted by a peer ACL) with duration of 30 seconds to maintain the session after link discovery loss:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# session protection for peer_acl duration 30

Related Commands


Command	Description
show mpls ldp neighbor	Displays information about LDP neighbors.

show mpls ldp backoff

To display information about the configured session setup backoff parameters and any potential LDP peers with which session setup attempts are being throttled, use the show mpls ldp backoff command in EXEC modeXR EXEC mode.

show mpls ldp backoff [location node-id | standby]

Syntax Description


location `node-id`	(Optional) Displays location information for the specified node ID.
standby	(Optional) Displays standby-node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC modeXR EXEC mode

Command History


Release	Modification
Release 3.7.2	This command was introduced.
Release 3.9.0	The location and standby keywords were added.

Usage Guidelines

You must enable the MPLS LDP application to use the show mpls ldp backoff command.

Task ID


Task ID	Operations
mpls-ldp	read

Examples

The following shows a sample output from the show mpls ldp backoff command:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp backoff
  
Backoff Time:
  Initial:15 sec, Maximum:120 sec
  
Backoff Table: (2 entries)
  
  LDP Id               Backoff (sec)  Waiting (sec)   
  -------------------- -------------- ----------------
  33.33.33.33:0          15               15
  11.11.11.11:0          30               30

This table describes the significant fields shown in the display.

Table 1. show mpls ldp backoff Command Field Descriptions
Field	Description
Backoff Time	Initial and maximum backoff time parameters, in seconds.
Backoff Table	List of discovered LDP neighbors for which session setup is being delayed because of previous failures to establish a session due to incompatible configuration. The backoff table incorporates the following information: LDP Id Identifies the LDP neighbors. Backoff (sec) Specifies the time that the session setup is delayed. Waiting (sec) Specifies an approximate time the session setup has been delayed.

Related Commands


Command	Description
	Configures LDP backoff parameters.
show mpls ldp forwarding	Displays the contents of MPLS forwarding table.
show mpls ldp bindings	Displays the contents of LDP LIB.

show mpls ldp bindings

To display the contents of the Label Information Base (LIB), use the show mpls ldp bindings command in EXEC command.

show mpls ldp [] bindings [prefix/ length ] [advertisement-acls] [brief] [detail] [local] [local-label label [to label]] [local-only] [neighbor address] [remote-only] [remote-label label [to label]] [summary] [location node-id | standby]

Syntax Description


`prefix`	(Optional) Destination prefix, written in A.B.C.D format.
`length`	(Optional) Network mask length, in bits. Range is 0 to 32.
advertisement-acls	(Optional) Displays the label bindings as applied for (advertisement) outbound label filtering ACLs.
brief	(Optional) Displays all the prefixes in the LDP database.
detail	(Optional) Displays the total counts of advertised-to and remote-binding peers in IP address sort order, with remote bindings in tabular format.
local	(Optional) Displays the local label bindings.
local-label `label` [to `label` ]	(Optional) Displays entries matching local label values. Add the `label` to `label` argument to indicate the label range.
local-only	(Optional) Displays binding matches with a local label only.
neighbor `address`	(Optional) Displays the label bindings assigned by the selected neighbor.
remote-only	(Optional) Displays bindings matches with a remote label only.
remote-label `label` [to `label` ]	(Optional) Displays entries matching the label values assigned by a neighbor router. Add the `label` to`label` argument to indicate the label range. Range is from 0 to 2147483647.
summary	(Optional) Displays a summary of the contents of the Label Information Base (LIB).
location `node-id`	(Optional) Displays location information for the specified node ID.
standby	(Optional) Displays standby-node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC

Command History


Release	Modification
Release 3.7.2	This command was introduced.

Usage Guidelines

The show mpls ldp bindings command displays local and remote label bindings learned from neighbors for non-BGP routes (such as IGP prefixes and static routes).

You can choose to view the entire database or a subset of entries according to the following criteria:

Prefix
Input or output label values or ranges
Neighbor advertising the label

Note

The show mpls ldp bindings summary command displays summarized information from the LIB and is used when testing scalability or when deployed in a large scale network.

Task ID


Task ID	Operations
mpls-ldp	read

Examples

The following sample output displays the contents of the LIB for the default routing domain:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp bindings
  
     5.41.0.0/16 , rev 4 
          local binding: label:IMP-NULL
          No remote bindings
  5.43.9.98/32 , rev 6 
          local binding: label:IMP-NULL
          No remote bindings
  10.10.2.0/24 , rev 12 
          local binding: label:IMP-NULL
          remote bindings : 
              lsr:10.255.255.255:0, label:16 
              lsr:10.256.256.256:0, label:IMP-NULL 
  10.10.3.0/24 , rev 10 
          local binding: label:IMP-NULL
          remote bindings : 
              lsr:10.255.255.255:0, label:IMP-NULL 
              lsr:10.256.256.256:0, label:22 
  22.22.22.22/32 , rev 14 
          local binding: label:16
          remote bindings : 
              lsr:10.255.255.255:0, label:17 
              lsr:10.256.256.256:0, label:IMP-NULL
  33.33.33.33/32 , rev 2 
          local binding: label:IMP-NULL
          remote bindings : 
              lsr:10.255.255.255:0, label:18 
              lsr:10.256.256.256:0, label:23

The following sample output shows detailed information for the total counts of advertised-to and remote-binding peers in IP address sort order, with remote bindings for 150.150.150.150/32:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp bindings 150.150.150.150/32 detail
  
  150.150.150.150/32, rev 2
       Local binding: label: IMP-NULL
         Advertised to: (6 peers)
           120.120.120.120:0  130.130.130.130:0  150.150.150.1:0  150.150.150.2:0
           150.150.150.3:0    150.150.150.4:0
       Remote bindings:    (3 peers)
           Peer                Label
  -----------------         --------
         120.120.120.120:0     27018
         130.130.130.130:0     26017
         160.160.160.160:0     27274

The following sample output specifies a network number and displays labels learned from label switched router (LSR) 10.255.255.255 for all networks. The neighbor keyword is used to suppress the output of remote labels learned from other neighbors:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp bindings neighbor 10.255.255.255
  
  10.10.2.0/24 , rev 12 
          local binding: label:IMP-NULL
          remote bindings : 
              lsr:10.255.255.255, label:16 
  10.10.3.0/24 , rev 10 
          local binding: label:IMP-NULL
          remote bindings : 
              lsr:10.255.255.255:0, label:IMP-NULL 
  22.22.22.22/32 , rev 14 
          local binding: label:16
          remote bindings : 
              lsr:10.255.255.255:0, label:17 
  33.33.33.33/32 , rev 2 
          local binding: label:IMP-NULL
          remote bindings : 
              lsr:10.255.255.255:0, label:18 
  44.44.44.44/32 , rev 16 
          local binding: label:17
          remote bindings : 
              lsr:10.255.255.255:0, label:IMP-NULL

This table describes the significant fields shown in the display.

Table 2. show mpls ldp bindings and show mpls ldp bindings neighbor Command Field Descriptions
Field	Description
a.b.c.d/n	IP prefix and mask for a particular destination (network/mask).
rev	Revision number (rev) that is used internally to manage label distribution for this destination.
local binding	Locally assigned label for a prefix.
remote bindings	Outgoing labels for this destination learned from other LSRs.¹ Each item in this list identifies the LSR from which the outgoing label was learned and reflects the label associated with that LSR. Each LSR in the transmission path is identified by its LDP identifier.

¹ Label switched routers.

The following sample output summarizes the content by using the summary keyword:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp bindings summary
  
  LIB Summary:
    Total Prefix   : 20 
    Revision No    : Current:34, Advertised:34
    Local Bindings : 14
        NULL    : 10 (implicit:10, explicit:0)
        Non-NULL: 4 (lowest:48, highest:51)
    Remote Bindings: 24

This table describes the significant fields shown in the display.

Table 3. show mpls ldp bindings summary Command Field Descriptions
Field	Description
Total Prefix	Number of prefixes (routes) known to LDP LIB. All invalid and timed-out routes display as no-routes.
Revision No	Current revision number of LIB entries as well as the minimum revision number that has been advertised to all peers.
Local Bindings	Total number of local bindings, with information on how many of them are Null, non-null, and lowest/highest label assigned or allocated by LDP.
Remote Bindings	Number of remote bindings.

The following sample output shows the access-list advertisement:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp bindings advertisement-acls
  
  Advertisement Spec: 
          Prefix ACL = 'pfx_11'
          Prefix ACL = 'pfx_22'
          Prefix ACL = 'pfx_40_1'; Peer ACL = 'peer_11'
  
  5.41.0.0/16 , rev 82 
  11.11.11.11/32 , rev 69 
          Advert ACL(s): Prefix ACL 'pfx_11' 
  20.20.20.20/32 , rev 83 
  22.22.22.22/32 , rev 78 
          Advert ACL(s): Prefix ACL 'pfx_22' 
  40.1.1.0/24 , rev 79 
          Advert ACL(s): Prefix ACL 'pfx_40_1'; Peer ACL 'peer_11'

This table describes the significant fields shown in the display.

Table 4. show mpls ldp bindings advertisement-acls Command Field Descriptions
Field	Description
Advertisement Spec	Lists all prefix and peer access-lists used as outbound label advertisement control.
Advert ACL(s)	Lists the first matching rule (if any) for the prefix entry for outbound label advertisement control (for prefix-acl).

The following sample output shows all the prefixes in the LDP database using the brief keyword:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp bindings brief
  
  Prefix                Local Advertised Remote Bindings
                        Label (peers)         (peers)
  ------------------ -------- ---------- ---------------
  10.1.2.2/32            -          0           1
  10.2.3.4/32            16010      396         0
  209.165.201.1/32            16004      396         3
  10.0.0.0/24           19226      396         395

The following sample output shows that the binding matches with a local label:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp bindings local-only
  
  10.12.32.2/32, rev 4
          Local binding: label: IMP-NULL
          No remote bindings

The following sample output shows that the binding matches with a remote label:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp bindings remote-only
  
  10.26.4.0/24, rev 0
          No local binding
          Remote bindings: (1 peers)
              Peer                Label   
              -----------------   --------
              10.6.6.6:0          IMP-NULL
  10.43.4.0/24, rev 0
          No local binding
          Remote bindings: (1 peers)
              Peer                Label   
              -----------------   --------
              10.4.4.4:0          IMP-NULL
  10.46.4.0/24, rev 0
          No local binding
          Remote bindings: (2 peers)
              Peer                Label   
              -----------------   --------
              10.4.4.4:0          IMP-NULL
              10.6.6.6:0          IMP-NULL

Related Commands


Command	Description
label accept	Configures the LDP remote label acceptance.
label advertise	Configures the LDP local label advertisement control.
show mpls ldp neighbor	Displays information on the LDP neighbors.
show mpls ldp forwarding	Displays the contents of the LDP forwarding database.

show mpls ldp capabilities

To display the database capability information for an LDP session, use the show mpls ldp capabilities command in EXEC modeXR EXEC mode.

show mpls ldp [vrf vrf-name] capabilities [detail] [location node-id | standby]

Syntax Description


vrf `vrf-name`	(Optional) Displays the VRF information for the specified VRF.
detail	(Optional) Displays detailed database capability information for an LDP session.
location `node-id`	(Optional) Displays location information for the specified node ID.
standby	(Optional) Displays standby node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC modeXR EXEC mode

Command History


Release	Modification
Release 6.0	This command was introduced

Usage Guidelines

No specific guidelines impact the use of this command.

Task ID


Task ID	Operation
mpls-ldp	read

Examples

The following shows a sample output from the show mpls ldp capabilities command:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp capabilities

  Type     Description                                Owner       
  ------   ----------------------------------------   ------------
  0x50b    Typed Wildcard FEC                         LDP         
  0x3eff   Cisco IOS-XR                               LDP         
  0x508    MP: Point-to-Multipoint (P2MP)             mLDP        
  0x509    MP: Multipoint-to-Multipoint (MP2MP)       mLDP        
  0x703    P2MP PW                                    L2VPN-AToM

show mpls ldp discovery

To display the status of the LDP discovery process, use the show mpls ldp discovery command in EXEC modeXR EXEC mode.

Syntax Description

type

(Optional) Interface type. For more information, use the question mark (?) online help function.

interface-path-id

Physical interface or a virtual interface.

Note

Use the show interfaces command to see a list of all possible interfaces currently configured on the router.

For more information about the syntax for the router, use the question mark (?) online help function.

brief

(Optional) Displays concise information about a specified LDP-enabled interface.

link

(Optional) Displays link information for LDP discovery.

targeted

(Optional) Displays targeted information for LDP discovery.

summary

(Optional) Displays summarized information for LDP discovery.

detail

(Optional) Displays detailed information (including, inbound label filtering, session KAs, and session protection state) for an LDP session.

location node-id

(Optional) Displays location information for the specified node ID.

standby

(Optional) Displays standby node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC modeXR EXEC mode

Command History


Release	Modification
Release 3.7.2	This command was introduced.
Release 3.9.0	The following items were added: The link keyword was added. The targeted keyword was added.

Usage Guidelines

The show mpls ldp discovery command shows both link discovery and targeted discovery. When no interface filter is specified, this command generates a list of interfaces running the LDP discovery process. This command also displays neighbor discovery information for the default routing domain.

Task ID


Task ID	Operations
mpls-ldp	read

Examples

The following sample output is from the show mpls ldp discovery command:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp discovery
  
  Local LDP Identifier: 10.44.44.44:0
  Discovery Sources:
    Interfaces:
       POS 0/1/0/0 : xmit/recv
        LDP Id: 10.33.33.33:0, Transport address: 10.33.33.33
            Hold time: 15 sec (local:15 sec, peer:15 sec)

This table describes the significant fields shown in the display.

Table 5. show mpls ldp discovery Command Field Descriptions
Field	Description
Local LDP Identifier	LDP identifier for the local router. An LDP identifier is a 6-byte construct displayed in the form IP address:number. By convention, the first 4 bytes of the LDP identifier constitute the router ID; integers, starting with 0, constitute the final two bytes of the IP address:number construct.
Interfaces	Interfaces engaged in LDP discovery activity, as follows: xmit field Indicates that the interface is transmitting LDP discovery hello packets. recv field indicates that the interface is receiving LDP discovery hello packets. The LDP identifiers indicate the LDP neighbors discovered on the interface.
Transport Address	Address associated with this LDP peer (advertised in hello messages).
LDP Id	LDP identifier of the LDP peer.
Hold time	State of the forwarding hold timer and its current value.

The following sample output summarizes information for LDP discovery by using the summary keyword:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp discovery summary
  
  LDP Identifier: 139.0.0.1:0
  Interfaces:
    Configured: 2
    Enabled   : 1
  Discovery:
    Hello xmit: 1 (1 link)
    Hello recv: 1 (1 link)

This table describes the significant fields shown in the display.

Table 6. show mpls ldp discovery summary Command Field Descriptions
Field	Description
LDP Identifier	The LDP identifier for the local router.
Interfaces	Summary of interfaces engaged in LDP activity. Configured Number of interfaces configured for LDP. Enabled Number of interfaces on which LDP is actively enabled and is thus sending LDP hellos. An interface configured for LDP is enabled only if running IP and not in the down state.
Discovery	Summary of LDP discovery process. Hello xmit Number of local LDP discovery sources (including link and targeted hellos) emitting LDP hellos. Hello recv Number of discovered hello sources via link or targeted hello mechanics.

The following sample output shows the MPLS LDP discovery hello information in brief form:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp discovery brief
  
  Local LDP Identifier: 192.168.0.3:0
  
  Discovery Source         VRF Name       Peer LDP Id          Holdtime   Session
  -----------------------  ------------   -------------------  ---------  ----------
  PO0/3/0/2                default        192.168.0.1:0        15         Y

The following sample shows the MPLS LDP afi-all discovery brief command output:


RP/0/0/CPU0:router#show mpls ldp afi-all discovery brief 

Local LDP Identifier: 192.168.0.1:0

Discovery Source     AFI  VRF Name         Peer LDP Id          Holdtime Session
-------------------- ---- ---------------- -------------------- -------- -------
PO0/3/0/0            IPv6 default          192.168.0.2:0           15       Y   
                     IPv4 default          192.168.0.2:0           15       Y   
PO0/3/0/1            IPv4 default          192.168.0.3:0           15       Y   
PO0/3/0/2            IPv4 default          192.168.0.4:0           15       Y   
PO0/3/0/3            IPv6 default          192.168.0.3:0           15       Y   
PO0/3/0/4            IPv6 default          192.168.0.5:0           15       Y

Related Commands


Command	Description
	Configures LDP link hello parameters.
	Configures LDP targeted-hello parameters.
neighbor targeted	Configures LDP targeted neighbor.
session protection	Configures LDP session protection.
interface (MPLS LDP)	Configures LDP on an interface.
show mpls ldp neighbor	Displays information about LDP neighbors.

show mpls ldp forwarding

To display the Label Distribution Protocol (LDP) forwarding state installed in MPLS forwarding, use the show mpls ldp forwarding command in EXEC mode.

show mpls ldp [] forwarding [prefix/ length] [fast-reroute] [detail] [next-hop {address ip-address | interface interface-path-id | label label-value | neighbor ldp-id | unlabelled}] [local-label label-value] [location node-id | summary | standby]

Syntax Description


`prefix`	(Optional) Destination prefix, written in A.B.C.D format.
`length`	(Optional) Network mask length, in bits. Range is 0 to 32.



local-label `label-value`	(Optional) Displays the prefix with the specified local label. Range is from 0 to 1048575.


location `node-id`	(Optional) Displays location information for the specified node ID.

standby	(Optional) Displays standby-node specific information.

Command Default

No default behavior or values

Command Modes

EXEC

Command History


Release	Modification
Release 3.7.2	This command was introduced.
Release 3.9.0	The following items were added: The detail keyword. Sample output for the detail keyword. The local-label keyword. The location keyword. The standby keyword.

Usage Guidelines

The show mpls ldp forwarding command displays the LDP forwarding entries and provides LDP view of its installed forwarding entries.

Task ID


Task ID	Operations
mpls-ldp	read

Examples

This is a sample output from the show mpls ldp forwarding command:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp forwarding 
  
  Prefix             Label Label      Outgoing     Next Hop        GR Stale
                     In    Out        Interface
  ------------------ ----- ---------- ------------ --------------- -- -----
  172.16.0.1/32         22    ImpNull    PO0/2/0/1      12.0.0.2        N  N
  3.0.0.1/32         24    20         PO0/2/0/1      12.0.0.2        N  N
  3.0.0.2/32         25    21         PO0/2/0/1      12.0.0.2        N  N
  3.0.0.3/32         26    22         PO0/2/0/1      12.0.0.2        N  N
  4.4.4.4/32         20    ExpNullv4  tt10           4.4.4.4         N  N
  4.4.4.5/32         21    ExpNullv4  tt10           4.4.4.4         N  N
  123.0.0.0/24       23    ImpNull    PO0/2/0/1      12.0.0.2        N  N
  192.168.0.1/32       16000   16001      PO0/2/0/3.1  131.1.1.4         Y  N 
                           16002      PO0/2/0/3.2  131.1.2.4         Y  N 
                           16003      PO0/2/0/3.3  131.1.3.4         N  N  
                           16002      PO0/2/0/1    192.11.1.1 (!)    Y  N 
                           Unlabelled PO0/2/0/2    192.11.2.1 (!)    N  N

Note

The (!) symbol referes to a non-primary LFA backup path.

This sample output shows detailed information for the LDP timestamp that is used for routing and forwarding update from the detail keyword:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp forwarding 10.0.0.1/32 detail
  
  Prefix           Label   Label      Outgoing     Next Hop        GR Stale
                   In      Out        Interface                            
  ---------------- ------- ---------- ------------ --------------- -- -----
  192.168.0.1/32       16000   16001     PO0/2/0/3.1   131.1.1.4         N  N
                           [ Protected; path-id 1 backup-path-id 33; 
                           [peer 13.13.13.1:0 ]
                           16002      PO0/2/0/3.2  131.1.2.4         Y  N 
                           [ Protected; path-id 2 backup-path-id 33; 
                           peer 13.13.13.1:0 ]
                           16003      PO0/2/0/3.3  131.1.3.4         N  N
                           [ Protected; path-id 3 backup-path-id 34;
                           peer 13.13.13.2:0 ]  
                           16002      PO0/2/0/1    192.11.1.1 (!)    Y  N
                           [ Backup; path-id 33; peer 14.14.14.1:0 ] 
                           Unlabelled PO0/2/0/2    192.11.2.1 (!)    N  N
                           [ Backup; path-id 34 ]  
    
  
    Routing update   : Mar 31 13:35:25.348 (00:55:32 ago)
    Forwarding update: Mar 31 13:35:25.349 (00:55:32 ago)

Note

The (!) symbol referes to a non-primary LFA backup path.

This sample output shows only LDP prefixes with protection (ECMP or secondary LFA backups) update from the fast-reroute keyword:

This table describes the significant fields shown in the display.

Table 7. show mpls ldp forwarding Command Field Descriptions
Field	Description
Prefix/mask	Prefix on the FEC² for an MPLS forwarding entry.
Label In	Local label assigned to the prefix/mask.
Label Out	Outgoing label for the prefix/mask.
Outgoing Interface	Outgoing physical interface.
Next Hop	Next Hop address.
GR	Graceful restart status (Y or N).
Stale	Status of the entry, stale or not stale. An entry is marked stale when the next-hop graceful restart neighbor disconnects and is unmarked when neighbor reconnects and refreshes the label.
Chkpt	Status of the entry, checkpointed or not checkpointed.

² Forwarding Equivalence Class.

Related Commands


Command	Description
graceful-restart (MPLS LDP)	Configures the LDP graceful restart feature.
show mpls ldp bindings	Displays the contents of LDP LIB.

show mpls ldp graceful-restart

To display the status of the Label Distribution Protocol (LDP) graceful restart, use the show mpls ldp graceful-restart command in EXEC mode.

show mpls ldp graceful-restart [location node-id] [standby]

Syntax Description


location `node-id`	(Optional) Displays location information for the specified node ID.
standby	(Optional) Displays standby-node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC

Command History


Release	Modification
Release 3.7.2	This command was introduced.
Release 3.9.0	The location and standby keywords were added.

Usage Guidelines

The show mpls ldp graceful-restart command displays LDP graceful-restart-related information when the graceful-restart command is enabled.

Task ID


Task ID	Operations
mpls-ldp	read

Examples

The following shows a sample output from the show mpls ldp graceful-restart command:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp graceful-restart
  
    Forwarding State Hold timer : Not Running
    GR Neighbors                : 1
  
     Neighbor ID      Up  Connect Count  Liveness Timer      Recovery Timer    
     ---------------  --  -------------  ------------------  ------------------
     10.0.0.2                Y        1                -                   -

This table describes the significant fields shown in the display.

Table 8. show mpls ldp graceful-restart Command Field Descriptions
Field	Description
Forwarding State Hold timer	State of the hold timer—running or not running.
GR Neighbors	Number of graceful restartable neighbors.
Neighbor ID	Router ID of each neighbor.
Up	Neighbor up or down.
Connect Count	Number of times the same neighbor has reconnected.
Liveness Timer	State of the liveness timer (running or not running) and its expiration time, if running.
Recovery Timer	State of the recovery timer (running or not running) and its expiration time, if running.

Related Commands


Command	Description
graceful-restart (MPLS LDP)	Configures the LDP graceful restart feature.
show mpls ldp neighbor	Displays information about LDP neighbors.

show mpls ldp igp sync

To display Label Distribution Protocol (LDP) Interior Gateway Protocol (IGP) synchronization information on interface(s), use the show mpls ldp igp sync command in EXEC mode.

show mpls ldp [] igp sync [interface type interface-path-id] [location node-id] [standby]

Syntax Description

interface

(Optional) Displays the interface type.

type

(Optional) Interface type. For more information, use the question mark (?) online help function.

interface-path-id

(Optional) Physical interface or a virtual interface.

Note

Use the show interfaces command to see a list of all possible interfaces currently configured on the router.

For more information about the syntax for the router, use the question mark (?) online help function.

location node-id

(Optional) Displays location information for the specified node ID.

standby

(Optional) Displays standby node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC

Command History


Release	Modification
Release 3.7.2	This command was introduced.
Release 3.9.0	The location and standby keywords were added.

Usage Guidelines

LDP IGP synchronization addresses traffic loss issues as a result of synchronization between MPLS LDP and IP (IGP). For instance, upon a link up, IGP can advertise a link before MPLS converges on the link. Also, the IGP link is still used even when MPLS session goes down and MPLS LSP is broken on this link. The use of IGP link is determined based on MPLS LDP convergence synchronization status on the link.

Use the show mpls ldp igp sync command to display MPLS convergence status. The configuration for LDP IGP synchronization resides in IGPs (OSPF, ISIS); accordingly, LDP displays and advertises this information for all LDP-enabled interfaces (regardless if the interface is configured for LDP IGP).

Task ID


Task ID	Operations
mpls-ldp	read

Examples

The following shows a sample output from the show mpls ldp igp sync command:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp igp sync
    
  POS0/3/0/2:
    VRF: 'default' (0x60000000)
    Sync delay: Disabled
    Sync status: Ready
      Peers:
      192.168.0.1:0   (GR)

This table describes the significant fields shown in the display.

Table 9. show mpls ldp igp sync Command Field Descriptions
Field	Description
VRF	VRF of the interface.
Sync status	MPLS LDP convergence status on a given link. Ready indicates that the link is converged and is ready to be used by IGP. Not Ready with Deferred means that the link fulfills LDP IGP synchronization requirements but is deferred by LDP IGP synchronization delay timeout configuration setting. Not Ready means that the link is not ready to be used by IGP.
Peers	List of peers converged on the given link. If the peer session is GR³-enabled, output is tagged as GR. If GR-only reachability is indicated due to a GR neighbor record recovered from checkpoint after local start, then Chkpt-created flag is also set.

³ Graceful Restart.

Related Commands


Command	Description
igp sync delay	Configures LDP IGP sync delay timeout.

show mpls ldp interface

To display information about LDP-enabled interfaces, use the show mpls ldp interfaces command in EXEC mode.

show mpls ldp [] interface [type interface-path-id | summary] [brief] [location node-id | standby]

Syntax Description

type

(Optional) Interface type. For more information, use the question mark (?) online help function.

interface-path-id

Physical interface or a virtual interface.

Note

Use the show interfaces command to see a list of all possible interfaces currently configured on the router.

For more information about the syntax for the router, use the question mark (?) online help function.

summary

(Optional) Displays summary information about a specified LDP-enabled interface.

brief

(Optional) Displays concise information about a specified LDP-enabled interface.

detail

(Optional) Displays detailed information about a specified LDP-enabled interface.

location node-id

(Optional) Displays location information for the specified node ID.

standby

(Optional) Displays standby-node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC

Command History


Release	Modification
Release 3.7.2	This command was introduced.
Release 3.9.0	The location and standby keywords were added.

Task ID


Task ID	Operations
mpls-ldp	read

Examples

The following shows a sample output from the show mpls ldp interface command:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp interface
  
  Interface GigabitEthernet0/3/0/3
      No LDP config
  Interface POS0/2/0/0
      No LDP config
      Auto-config items:
         ospf/100/0
  Interface POS0/2/0/1
      No LDP config
      Auto-config items:
         ospf/100/0
  Interface POS0/2/0/2
      No LDP config
      Auto-config items:
         ospf/100/0
  Interface POS0/2/0/3
      No LDP config
      Auto-config items:
         ospf/100/0

This table describes the significant fields shown in the display.

Table 10. show mpls ldp interface Command Field Descriptions
Field	Description
Auto-config items	Lists IGPs that specify an interface for MPLS LDP auto-configuration: OSPF `ospf instance area` ISIS `isis instance`

Related Commands


Command	Description
igp auto-config disable	Disables LDP auto-configuration.

show mpls ldp neighbor

To display the status of Label Distribution Protocol (LDP) sessions, use the show mpls ldp neighbor command in EXEC mode.

show mpls ldp neighbor [ip-address] [type interface-path-id] [brief] [detail] [gr] [location node-id] [non-gr] [sp] [standby]

Syntax Description

ip-address

(Optional) Neighbor IP address.

type

(Optional) Interface type. For more information, use the question mark (?) online help function.

interface-path-id

Physical interface or a virtual interface.

Note

Use the show interfaces command to see a list of all possible interfaces currently configured on the router.

For more information about the syntax for the router, use the question mark (?) online help function.

brief

(Optional) Displays the existing LDP sessions in brief format.

detail

(Optional) Displays detailed information (including, inbound label filtering, session KAs, and session protection state) for an LDP session.

gr

(Optional) Displays graceful restartable neighbors.

location node-id

(Optional) Displays location information for the specified node ID.

non-gr

(Optional) Displays non-graceful restartable neighbors.

sp

(Optional) Displays neighbors with session protection.

standby

(Optional) Displays standby-node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC

Command History


Release	Modification
Release 3.7.2	This command was introduced.
Release 3.9.0	The following items were added: The location keyword was added. Sample output for the brief keyword was modified to add the NSR and IPv4 Label columns.

Usage Guidelines

The show mpls ldp neighbor command provides information about all LDP neighbors in the entire routing domain—conversely, the show output is filtered to display:

LDP neighbors with specific IP addresses
LDP neighbors on a specific interface
LDP neighbors that are graceful restartable
LDP neighbors that are nongraceful restartable
LDP neighbors enabled with session protection

Task ID


Task ID	Operations
mpls-ldp	read

Examples

The following shows a sample output from the show mpls ldp neighbor command using an IP address:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp neighbor 4.4.4.4
  
Peer LDP Identifier: 4.4.4.4:0
  TCP connection: 14.1.0.41:38022 - 10.0.0.1:646
  Graceful Restart: Yes (Reconnect Timeout: 120 sec, Recovery: 96 sec)
  Session Holdtime: 180 sec
  State: Oper; Msgs sent/rcvd: 1721/1716; Downstream-Unsolicited
  Up time: 1d00h
  LDP Discovery Sources:
    IPv4: (1)
      GigabitEthernet0/1/0/0
    IPv6: (0)
  Addresses bound to this peer:
    IPv4: (3)
      4.4.4.4        14.1.0.41      24.1.0.4       
    IPv6: (0)

The following shows a sample output from the show mpls ldp neighbor command using the non-gr keyword:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp neighbor non-gr
  
  Peer LDP Identifier: 10.44.44.44:0
    TCP connection: 10.44.44.44:65535 - 10.33.33.33:646
    Graceful Restart: No
    State: Oper; Msgs sent/rcvd: 49/46
    Up time: 00:33:33
    LDP Discovery Sources: 
      POS 0/1/0/0
    Addresses bound to this peer:
      10.44.44.44     10.10.3.2      
  Peer LDP Identifier: 10.22.22.22:0
    TCP connection: 10.22.22.22:646 - 10.33.33.33:65530
    Graceful Restart: No
    State: Oper; Msgs sent/rcvd: 48/45
    Up time: 00:33:11
    LDP Discovery Sources: 
      POS 0/2/0/0
    Addresses bound to this peer:
      10.22.22.22     10.10.2.1

This table describes the significant fields shown in the display.

Table 11. show mpls ldp neighbor Command Field Descriptions
Field	Description
Peer LDP Identifier	LDP identifier of the neighbor (peer) for this session.
TCP connection	TCP connection used to support the LDP session, shown in the following format: neighbor IP address peer port local IP address local port
Graceful Restart	Graceful-restart status (Y or N).
State	State of the LDP session. Generally this is Oper (operational), but transient is another possible state.
Msgs sent/rcvd	Number of LDP messages sent to and received from the session peer. The count includes the transmission and receipt of periodic keepalive messages, which are required for maintenance of the LDP session.
Up time	The length of time that this session has been up for (in hh:mm:ss format).
LDP Discovery Sources	The source(s) of LDP discovery activity leading to the establishment of the LDP session.
Addresses bound to this peer	The known interface addresses of the LDP session peer. These are addresses that might appear as “next hop” addresses in the local routing table. They are used to maintain the LFIB⁴.

⁴ LFIB = Label Forwarding Information Base.

The following shows a sample output from the show mpls ldp neighbor command using the brief keyword:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp neighbor brief
  
Peer               GR  NSR  Up Time     Discovery   Addresses     Labels    
                                        ipv4  ipv6  ipv4  ipv6  ipv4   ipv6 
-----------------  --  ---  ----------  ----------  ----------  ------------
4.4.4.4:0          Y   N    1d00h       1     0     3     0     5      0    
46.46.46.2:0       N   N    1d00h       1     1     3     3     5      5    
46.46.46.46:0      Y   N    1d00h       2     2     4     4     5      5    
6.6.6.1:0          Y   N    23:25:50    0     1     0     2     0      5

This table describes the significant fields shown in the display.

Table 12. show mpls ldp neighbor brief Command Field Descriptions
Field	Description
Peer	LDP identifier of the neighbor (peer) for this session.
GR	Graceful-restart status (Y or N).
Up Time	Time the session has been up (in hh:mm:ss format).
Discovery	Number of LDP discovery sources corresponding to the neighbor.
Address	Number of addresses bound to this peer.

The following shows a sample output from the show mpls ldp neighbor command using the detail keyword:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp neighbor detail
 
  Peer LDP Identifier: 172.16.0.1:0
    TCP connection: 172.16.0.1:11707 - 10.0.0.1:646
    Graceful Restart: No
    Session Holdtime: 180 sec
    State: Oper; Msgs sent/rcvd: 33/29
    Up time: 00:13:37
    LDP Discovery Sources: 
       POS0/2/0/1
      Targeted Hello (10.0.0.1 ->172.16.0.1, active)
    Addresses bound to this peer:
      23.0.0.2 2.0.0.2        123.0.4.2       10.42.37.119    
      10.2.2.2        
    Peer holdtime: 180 sec; KA interval: 60 sec; Peer state: Estab
    Clients: Dir Adj Client
    Inbound label filtering: accept acl 'pfx_acl2'
    Session Protection:
      Enabled, state: Ready
      Duration: 30 seconds

This table describes the significant fields shown in the display.

Table 13. show mpls ldp neighbor detail Command Field Descriptions
Field	Description
Peer LDP Identifier	LDP identifier of the neighbor (peer) for this session.
TCP connection	TCP connection used to support the LDP session, shown in the following format: neighbor IP address peer port local IP address local port
Graceful Restart	Graceful-restart status (Y or N).
Session Holdtime	Session hold time, in seconds.
State	State of the LDP session (operational or transient).
Msgs sent/rcvd	Number of LDP messages sent to and received from the session peer. The count includes the transmission and receipt of periodic keepalive messages, which are required for maintenance of the LDP session.
Up time	Time the session has been up for (in hh:mm:ss format).
Peer holdtime	Time to keep LDP peer session up without receipt of LDP protocol message from a peer.
Peer state	Peer session state.
Peer holdtime	Time to keep LDP peer session up without receipt of LDP protocol message from a peer.
Clients	LDP (internal) clients requesting session with a neighbor.
Inbound label filtering	LDP neighbor inbound filtering policy.
Session Protection	State of the session protection: Incomplete Targeted discovery requested but not yet up. Ready Targeted discovery and at least one link hello adjacency to the peer are up. Protecting Targeted discovery is up and there is no link hello adjacency to the peer. Targeted discovery is protecting and backing up link discoveries.
Duration	Maximum time to maintain session through targeted discovery upon loss of primary link discovery.
Holdtimer	When in “protecting” state, time to keep LDP peer session up without receipt of LDP protocol message from a peer.

Related Commands


Command	Description
graceful-restart (MPLS LDP)	Configures the LDP graceful restart feature.
label accept	Configures the LDP inbound label filtering feature.
session protection	Configures the LDP session protection feature.
show mpls ldp discovery	Displays the status of the LDP discovery process.

show mpls ldp nsr pending neighbor

To display the nonstop routing (NSR) pending neighbor information for an LDP session, use the show mpls ldp nsr pending neighbor command in the EXEC modeXR EXEC mode.

show mpls ldp [vrf vrf-name] nsr pending neighbor [lsr-id | ldp-id] [location node-id | standby]

Syntax Description


vrf `vrf-name`	(Optional) Displays the VRF information for the specified VRF.
`lsr-id`	(Optional) LSR ID of neighbor in A.B.C.D format.
`ldp-id`	(Optional) LDP ID of neighbor in A.B.C.D: format.
location `node-id`	(Optional) Displays location information for the specified node ID.
standby	(Optional) Displays standby-node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC modeXR EXEC mode

Command History


Release	Modification
Release 5.1.1	This command was introduced.

Task ID


Task ID	Operation
mpls-ldp	read

Examples

The following example shows how to display NSR pending neighbor information for an LDP session:



RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp nsr pending neighbor

show mpls ldp nsr statistics

To display the nonstop routing (NSR) statistics for an LDP session, use the show mpls ldp nsr statistics command in EXEC modeXR EXEC mode.

show mpls ldp [vrf vrf-name] nsr statistics [location node-id | standby] [neighbor [lsr-id | ldp-id] [location node-id | standby]]

Syntax Description


vrf `vrf-name`	(Optional) Displays the VRF information for the specified VRF.
location `node-id`	(Optional) Displays location information for the specified node ID.
standby	(Optional) Displays standby-node-specific information.
neighbor	(Optional) Displays neighbor information.
`lsr-id`	(Optional) LSR ID of neighbor in A.B.C.D format.
`ldp-id`	(Optional) LDP ID of neighbor in A.B.C.D: format.

Command Default

No default behavior or values

Command Modes

EXEC modeXR EXEC mode

Command History


Release	Modification
Release 5.1.1	This command was introduced.

Task ID


Task ID	Operation
mpls-ldp	read

Examples

The following shows a sample output from the show mpls ldp nsr statistics command:



RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp nsr statistics

Global Init Sync:
  Start: Oct 27 12:12:23 (00:01:20 ago)
  End:   Oct 27 12:12:23 (00:01:20 ago)

Protocol message stats:
  4 Peer, 5 Adj, 0 DHCB, 14/20 sent/rcvd Capabilities
  23 peer label for 18 FEC
  Send-Ack: 0 Lcl-Addr-WD

Sync message stats:
  Tx msgs/bytes = 32/5024
  Rx msgs/bytes = 0/0
  Max IPC Tx/Rx bytes = 4396/0
  Default MTU bytes = 4768, IPCs exceeding MTU = 0
  TX current/total fail count = 0/0
  IPC restart count = 1

show mpls ldp nsr summary

To display the nonstop routing (NSR) summary for an LDP session, use the show mpls ldp nsr summary command in EXEC modeXR EXEC mode.

show mpls ldp [vrf all] [vrf vrf-name] nsr summary [location node-id | standby] [all]

Syntax Description


vrf all	(Optional) Displays all LDP configured VRFs.
vrf `vrf-name`	(Optional) Displays the VRF information for the specified VRF.
location `node-id`	(Optional) Displays location information for the specified node ID.
standby	(Optional) Displays standby-node-specific information.
all	(Optional) Displays the aggregate summary across LDP processes and all VRFs.

Command Default

No default behavior or values

Command Modes

EXEC modeXR EXEC mode

Command History


Release	Modification
Release 5.1.1	This command was introduced.

Task ID


Task ID	Operation
mpls-ldp	read

Examples

The following shows a sample output from the show mpls ldp nsr summary command:



RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp nsr summary

Sessions:
   Total: 1, NSR-eligible: 1, Sync-ed: 1
      (1 Oper)

show mpls ldp parameters

To display current LDP parameters, use the show mpls ldp parameters command in EXEC mode.

show mpls ldp parameters [location node-id | standby]

Syntax Description


location `node-id`	(Optional) Displays location information for the specified node ID.
standby	(Optional) Displays standby-node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC

Command History


Release	Modification
Release 3.7.2	This command was introduced.
Release 3.9.0	The location and standby keywords were added.

Usage Guidelines

The show mpls ldp parameters command displays all LDP operational and configuration parameters.

Task ID


Task ID	Operations
mpls-ldp	read
network	read

Examples

The following shows a sample output from the show mpls ldp parameters command:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp parameters
  
  LDP Parameters:
    Protocol Version: 1
    Router ID: 10.11.11.11
    Null Label: Implicit
    Session:
      Hold time: 180 sec
      Keepalive interval: 60 sec
      Backoff: Initial:15 sec, Maximum:120 sec
    Discovery:
      Link Hellos:     Holdtime:15 sec, Interval:5 sec
      Targeted Hellos: Holdtime:90 sec, Interval:10 sec
                       (Accepting peer ACL 'peer_acl_10')
    Graceful Restart:
      Enabled (Configured)
      Reconnect Timeout:120 sec, Forwarding State Holdtime:180 sec
    Timeouts:
      Binding with no-route: 300 sec
      LDP application recovery (with LSD): 360 sec
    OOR state
      Memory: Normal

This table describes the significant fields shown in the display.

Table 14. show mpls ldp parameters Command Field Descriptions
Field	Description
Protocol Version	Version of LDP running on the platform.
Router ID	Currently used router ID.
Null Label	LDP use of implicit-null or explicit-null as label for prefixes where it has to use a null label.
Session Hold time	Time LDP session is to be maintained with an LDP peer without receiving LDP traffic or an LDP keepalive message from the peer.
Session Keepalive interval	Time interval between consecutive transmissions of LDP keepalive messages to an LDP peer.
Session Backoff	Initial maximum backoff time for sessions.
Discovery Link Hellos	Time to remember that a neighbor platform wants an LDP session without receiving an LDP hello message from the neighbor (hold time), and the time interval between the transmission of consecutive LDP hello messages to neighbors (interval).
Discovery Targeted Hellos	Indicates the time: To remember that a neighbor platform wants an LDP session when the neighbor platform is not directly connected to the router or the neighbor platform has not sent an LDP hello message. This intervening interval is known as hold time. Interval between the transmission of consecutive hello messages to a neighbor not directly connected to the router and if targeted hellos are being accepted, displaying peer-acl (if any).
Graceful Restart	Status of graceful-restart status (Y or N).
Timeouts	Various timeouts (of interest) that the LDP is using. One timeout is binding no route, which indicates how long the LDP waits for an invalid route before deleting it. It also shows restart recovery time for LSD and LDP.
OOR state	Out of resource memory state: Normal, Major, or Critical.

Related Commands


Command	Description
	Configures the parameters for the LDP backoff mechanism.
	Configures the interval between transmission of LDP discovery messages.
explicit-null	Configures a router to advertise an explicit-null label.
graceful-restart (MPLS LDP)	Configures the LDP graceful restart feature.
session holdtime (MPLS LDP)	Configures keepalive message hold time for LDP sessions.
neighbor targeted	Specifies the preferred interface or IP address of a Loopback interface for determining the LDP router ID.

show mpls ldp statistics fwd-setup

To display the statistics of the forwarding setup counters related to RIB/LSD, use the show mpls ldp statistics fwd-setup command in EXEC modeXR EXEC mode.

show mpls ldp [vrf vrf-name] statistics fwd-setup [location node-id | standby]

Syntax Description


vrf `vrf-name`	(Optional) Displays the VRF information for the specified VRF.
location `node-id`	(Optional) Displays location information for the specified node ID.
standby	(Optional) Displays standby-node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC modeXR EXEC mode

Command History


Release	Modification
Release 5.1.1	This command was introduced.

Task ID


Task ID	Operation
mpls-ldp	read

Examples

The following shows a sample output from the show mpls ldp statistics fwd-setup command:



RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp statistics fwd-setup

RIB
===

Thread counters: 
  Events In           : 10
  Events Out          : 39
  RIB fetch throttled : 0 (0 during last throttle)

TC Thread counters: 
  Events In           : 39 (3 skipped)
  Events Out          : 12 (0 failed, 2 skipped)

Address Family: IPv4
  RIB server connects: 1
  RIB converged: Yes
  Op counters: 
    Fetch          : 4 (2 buffers per fetch)
                     no-data: 0
                     callbacks: 33 routes, 3 convg, 0 rcmd
    Route Up       : 33 (0 protected; Paths: 29/0/0 total/backup/protected)
    Route Down     : 0
    Route Filtered : 5 (0 intern, 5 misc, 0 alloc, 0 admin,
                        0 unsupp-intf 0, unsupp-protection,
                        0 bgp, 0 bgp-unlabelled, 0 ibgp-no-lbl-ucast)

MFI
===

Thread counters: 
  Events In           : 9
  Events Out          : 8
  LSD Rsrc-Complete   : 1
  LSD server connects : 1

Op counters: 
                             Successful      Failed
                             ----------      ------
    Control              :            3           0
    RCMD Markers         :            0           0
    State cleanup        :            0           0
    Interface Enable     :            5           0
    Interface Disable    :            0           0
    Label alloc          :            4           0
    Label alloc - mldp   :            0           0
    Label free           :            0           0
    Label free - mldp    :            0           0
    Rewrite create       :            6           0
    Rewrite delete       :            0           0
    Label/Rewrite create :            0           0
    Label/Rewrite delete :            0           0
    Label OOR cleared    :            3           0

    Total LSD Reqs/Msgs  :            7           0

LSD flow control status: 
  Flow control            : 0
  Flow control cnt        : 0
  Evt queue item cnt      : 0
  Last flow control       : N/A

show mpls ldp statistics msg-counters

To display statistics of the messages exchanged between neighbors, use the show mpls ldp statistics msg-counters command in EXEC mode.

show mpls ldp statistics msg-counters [ lsr-id | ldp-id ] [ location node-id | standby ]

Syntax Description


`lsr-id`	(Optional) LSR ID of neighbor in A.B.C.D format.
`ldp-id`	(Optional) LDP ID of neighbor in A.B.C.D: format.
location `node-id`	(Optional) Displays location information for the specified node ID.
standby	(Optional) Displays standby-node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC

Command History


Release	Modification
Release 3.7.2	This command was introduced.
Release 3.9.0	The location and standby keywords were added.

Usage Guidelines

The show mpls ldp statistics msg-counters command can provide counter information about different types of messages sent and received between neighbors.

Task ID


Task ID	Operations
mpls-ldp	read

Examples

The following shows a sample output from the show mpls ldp statistics msg-counters command:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp statistics msg-counters
  
  Peer LDP Identifier: 10.33.33.33:0
     Msg Sent: (80)
       Init             : 1
       Address          : 1
       Address_Withdraw : 0
       Label_Mapping    : 5
       Label_Withdraw   : 0
       Label_Release    : 0
       Notification     : 0
       KeepAlive        : 73
  
     Msg Rcvd: (81)
       Init             : 1
       Address          : 1
       Address_Withdraw : 0
       Label_Mapping    : 8
       Label_Withdraw   : 0
       Label_Release    : 0
       Notification     : 0
       KeepAlive        : 71

Table 1 describes the significant fields shown in the display.

Table 15. show mpls ldp statistics msg-counters Command Field Descriptions
Field	Description
Peer LDP Identifier	LDP identifier of the neighbor (peer).
Msg Sent	Summary of messages sent to the LDP peer.
Msg Rcvd	Summary of messages received from the LDP peer.

Related Commands


Command	Description
	Clears MPLS LDP message counter values.
show mpls ldp bindings	Displays the contents of LDP LIB.
show mpls ldp neighbor	Displays LDP neighbor information.

show mpls ldp summary

To display a summary of LDP information, use the show mpls ldp summary command in EXEC mode.

show mpls ldp summary [location node-id | standby]

Syntax Description


location `node-id`	(Optional) Displays location information for the specified node ID.
standby	(Optional) Displays standby-node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC

Command History


Release	Modification
Release 3.7.2	This command was introduced.
Release 3.9.0	The location and standby keywords were added.

Usage Guidelines

The show mpls ldp summary command can provide information about the number of LDP neighbors, interfaces, forwarding state (rewrites), servers connection/registration, and graceful-restart information.

Task ID


Task ID	Operations
mpls-ldp	read

Examples

The following example shows a sample output from the show mpls ldp summary command:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp summary
   
			AFIs 					: IPv4
   Routes 			: 4
   Neighbors	: 1 (1 GR)
   Hello Adj	: 1
			Addresses : 3
			Interfaces: 4 LDP configured

The following example shows a sample output from the show mpls ldp summary all command:


RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp summary all
  
			VRFs         : 1 (1 oper)
			AFIs         : IPv4
			Routes    			: 4
   Neighbors 			: 1 (1 GR)
   Hello Adj 			: 1
			Addresses 			: 3
   Interfaces			: 4 (1 forward reference, 2 LDP configured)
   Collaborators:
   
                   	Connected  	Registered
                   	---------  	----------
       SysDB           	Y          Y
       IM              	Y          Y
							RSI														Y										-
							IP-ARM											Y          -
       IPv4-RIB        	Y          Y (1/1 tables)
       LSD             	Y          Y
							LDP-NSR-Partner  Y          -
							L2VPN-AToM       Y          -
    			mLDP             -          N

This table describes the significant fields shown in the display.

Table 16. show mpls ldp summary Command Field Descriptions
Field	Description
Routes	Number of known IP routes (prefixes).
Neighbors	Number of LDP neighbors, including targeted and graceful restartable neighbors.
Hello Adj	Number of discovered LDP discovery sources.
Interfaces	Number of known IP interfaces and number of LDP configured interfaces. LDP is configured on a forward-referenced interface which may not exist or for which no IP address is configured.
Addresses	Number of known local IP addresses.

Related Commands


Command	Description
show mpls ldp bindings	Displays the contents of LDP LIB.
show mpls ldp discovery	Displays the status of the LDP discovery process.
show mpls ldp forwarding	Displays the contents of the LDP forwarding database.
show mpls ldp graceful-restart	Displays the status of the LDP graceful restart.
show mpls ldp parameters	Displays current LDP parameter settings.

show mpls ldp trace vrf

To display the Label Distribution Protocol (LDP) VRF event traces, use the show mpls ldp trace vrf command in EXEC modeXR EXEC mode.

show mpls ldp trace vrf [binding] [capabilities] [config] [dev] [discovery] [error] [file file-name] [forwarding] [gr] [hexdump] [iccp] [igp-sync] [interface] [last] [location {node-id| name| all | mgmt-nodes}] [misc] [mldp] [nsr] [peer] [process] [pw] [reverse] [route] [since] [stats] [tailf] [unique] [usec] [verbose] [wide] [wrapping]

Syntax Description


binding	(Optional) Displays the binding event traces.
capabilities	(Optional) Displays the capabilities event traces.
config	(Optional) Displays the configuration event traces.
dev	(Optional) Displays the development private traces.
discovery	(Optional) Displays Hello or discovery and adj event traces.
error	(Optional) Displays error traces.
file `file-name`	(Optional) Displays trace of a specific file.
forwarding	(Optional) Displays forwarding event traces.
gr	(Optional) Displays graceful-restart event traces.
hexdump	(Optional) Displays traces in hexadecimal.
iccp	(Optional) Displays ICCP signaling event traces.
igp-sync	(Optional) Displays IGP sync event traces.
interface	(Optional) Displays interface event traces.
last	(Optional) Displays last number of entries.
location	(Optional) Identifies the location of the card whose CPU controller trace information you want to display.
`node-id`	The node-id argument is expressed in the rack/slot/module notation.
`name`	Specifies the name of the card.
`all`	Specifies all locations.
`mgmt-nodes`	Specifies all managements nodes.
misc	(Optional) Displays miscellaneous event traces.
mldp	(Optional) Displays MLDP event traces.
nsr	(Optional) Displays non-stop routing event traces.
peer	(Optional) Displays peer session event traces.
process	(Optional) Displays process-level event traces.
pw	(Optional) Displays L2VPN pseudo-wire event traces.
reverse	(Optional) Displays latest traces first.
route	(Optional) Displays route event traces.
since last-start	(Optional) Displays traces since the last start time.
stats	(Optional) Displays statistics.
tailf	(Optional) Displays new traces as they are added.
unique	(Optional) Displays unique entries with count.
usec	(Optional) Displays timestamp w/usec detail.
verbose	(Optional) Displays internal debugging information.
wide	(Optional) Do not display buffer name, node name and tid.
wrapping	(Optional) Displays wrapping entries.

Command Default

No default behavior or values

Command Modes

EXEC modeXR EXEC mode

Command History


Release	Modification
Release 5.1.1	This command was introduced.

Task ID


Task ID	Operation
mpls-ldp	read

Examples

The following example shows how to display the LDP VRF event traces:



RP/0/RP0RSP0/CPU0:router:hostname# show mpls ldp trace vrf

show lcc

To display label consistency checker (LCC) information, use the show lcc command in EXEC mode.

show lcc {ipv4 | ipv6} unicast {all | label | tunnel-interface | statistics | [summary | scan-id scan-id]} [vrf vrfname]

Syntax Description


ipv4	Specifies IP version 4 address prefixes.
ipv6	Specifies IP version 6 address prefixes.
unicast	Specifies unicast address prefixes.
all	Scans all routes.
label	Scans all labels.
tunnel-interface	Specifies the interface of a tunnel.
statistics	Displays route consistency check statistics information.
scan-id	Specifies the value of scan-id. Range is from 0 to 100000.
summary	Displays background route consistency check statistics summary information.
vrf `vrfname`	(Optional) Specifies a particular VPN routing and forwarding (VRF) instance or all VRF instances.

Command Default

None

Command Modes

IPv4 address family configuration

IPv6 address family configuration

Command History


Release	Modification
Release 4.2.0	This command was introduced.

Task ID


Task ID	Operations
IPv4	read
IPv6	read

Examples

The following example shows an outcome of the label consistency checker information:

RP/0/RP0RSP0/CPU0:router:hostname# show lcc ipv4 unicast all

Sending scan initiation request to IPv4 LSD ... done
Waiting for scan to complete (max time 600 seconds)......................
Scan Completed
Collecting scan results from FIBs (max time 30 seconds)... done
Number of nodes involved in the scan: 2
Number of nodes replying to the scan: 2

Legend: 
        ? - Currently Inactive Node, ! - Non-standard SVD Role
        * - Node did not reply

   Node                 Checks Performed                Errors

   0/2/CPU0                    6                             0
   0/0/CPU0                    6                             0

Related Commands


Command	Description
show rcc	Displays route consistency checker related information.

signalling dscp (LDP)

To assign label distribution protocol (LDP) signaling packets a differentiated service code point (DSCP) to assign higher priority to the control packets while traversing the network, use the signalling dscp command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

signalling dscp dscp

no signalling dscp

Syntax Description


`dscp`	DSCP priority value. Range is 0 to 63.

Command Default

LDP control packets are sent with precedence 6 (dscp : 48)

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 3.7.2	This command was introduced.

Usage Guidelines

DSCP marking improves signaling setup and teardown times.

Ordinarily, when LDP sends hello discovery or protocol control messages, these are marked using the default control packet precedence value (6, or dscp 48). You can use the signalling dscp command to override that DSCP value to ensure that all control messages sent are marked with a specified DSCP.

Note

While the signalling dscp command controls LDP signaling packets (Discovery hellos and protocol messages), it has no effect on ordinary IP or MPLS data packets.

Task ID


Task ID	Operations
mpls-ldp	read, write

Examples

The following example shows how to assign LDP packets a DSCP value of 56:


RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# signalling dscp 56

snmp-server traps mpls ldp

To inform a network management system of session and threshold cross changes, use the snmp-server traps mpls ldp command in global configuration mode.

snmp-server traps mpls ldp {up | down | threshold}

Syntax Description


up	Displays the session-up notification.
down	Displays the session-down notification.
threshold	Displays the session-backoff-threshold crossed notification.

Command Default

LDP does not send SNMP traps.

Command Modes

Global configuration

Command History


Release	Modification
Release 3.7.2	This command was introduced.

Usage Guidelines

The snmp-server traps mpls ldp command sends notifications to the SNMP server. There are three types of traps sent by LDP:

Session up: Generated when sessions go up.
Session down: Generated when sessions go down.
Threshold: Generated when attempts to establish a session fails. The predefined value is 8.

Task ID


Task ID	Operations
mpls-ldp	read, write
mpls-te	read, write
snmp	read, write

Examples

The following example shows how to enable LDP SNMP trap notifications for Session up:


RP/0/RP0RSP0/CPU0:router:hostname(config)# snmp-server traps mpls ldp up

static

To enable Multicast Label Distribution Protocol (MLDP) static LSP support, use static command in MPLS LDP MLDP configuration

address-family ipv4 static {mp2mp ip-address | p2mp ip-address}

Syntax Description


mp2mp `ip-address`	Specifies multi-point to multi-point (MP2MP) LSP root IP address followed by the number of LSPs in the range 1 to 1000.
p2mp `ip-address`	Specifies point to multi-point (P2MP) LSP root IP address followed by the number of LSPs in the range 1 to 1000.

Command Default

No default behavior or values

Command Modes

MPLS LDP MLDP configuration

Command History


Release	Modification
Release 5.1.1	This command was introduced.

Task ID


Task ID	Operation
mpls-ldp	read

Examples

The following example shows how to set up MLDP static support for MP2MP with forty five LSPs:



RP/0/RP0RSP0/CPU0:router:hostname(config-ldp-mldp)# address-family ipv4 static mp2mp 10.0.0.1 45

address-family ipv4/ipv6 label

To configure label control and policies on a specific IPv4 or IPv6 destination, use the address-family ipv4/ipv6 label command in the MPLS LDP configuration mode.

[ vrf vrf-name]address-family {} label [remote accept from ldp-id for prefix-acl] local [default-route] [allocate for {prefix-acl | host-routes}] [ advertise [to ldp-id for prefix-acl] [interface type interface-path-id ] ]

Syntax Description

label

(Optional) Configure label control and policies.

remote

(Optional) Configure remote/peer label control and policies.

accept

(Optional) Configure inbound label acceptance control.

from ldp-id

Specifies which LDP neighbors will receive label advertisements. LDP ID is written in A.B.C.D: format.

for prefix-acl

Specifies prefix destinations for which labels will be advertised.

local

(Optional) Configure local label control and policies.

default-route

(Optional) Enable MPLS forwarding for default route.

allocate

(Optional) Configure label allocation control.

for prefix-acl

Specifies prefix destinations for which labels will be allocated.

host-routes

Allocates labels for host routes only.

advertise

(Optional) Configure outbound label advertisement control.

to ldp-id

(Optional) Specifies which LDP neighbors will receive label advertisements. LDP ID is written in A.B.C.D: format.

for prefix-acl

(Optional) Specifies prefix destinations for which labels will be advertised.

interface

(Optional) Advertise interface host address.

type

Interface type. For more information, use the question mark (?) online help function.

interface-path-id

Physical interface or a virtual interface.

Note

Use the show interfaces command to see a list of all possible interfaces currently configured on the router.

For more information about the syntax for the router, use the question mark (?) online help function.

Command Default

No default behavior or values

Command Modes

MPLS LDP configuration

Command History


Release	Modification
Release 5.1.1	This command was introduced.

Task ID


Task ID	Operation
mpls-ldp	read, write

Examples

The following example shows how to configure label control and policies on a specific IPv4 destination:



RP/0/RP0RSP0/CPU0:router:hostname(config-ldp)# address-family ipv4	label

Bias-Free Language

Results

Chapter: MPLS Label Distribution Protocol Commands

MPLS Label Distribution Protocol Commands

backoff

Syntax Description

Command Default

Command Modes

Command History

Usage Guidelines

Task ID

Examples

Related Commands

clear mpls ldp forwarding

Syntax Description

Command Default

Command Modes

Command History

Usage Guidelines

Task ID

Examples

Related Commands

clear mpls ldp msg-counters neighbor

Syntax Description

Command Default

Command Modes

Command History

Usage Guidelines

Task ID

Examples

Related Commands

clear mpls ldp neighbor

Syntax Description

Command Default

Command Modes

Command History

Usage Guidelines

Task ID

Examples

Related Commands

clear mpls ldp nsr statistics neighbor

Syntax Description

Command Default

Command Modes

Command History

Task ID

Examples

debug mpls ldp rsi

Syntax Description

Command Default

Command Modes

Command History

Task ID

Examples

debug mpls ldp vrf

Syntax Description

Command Default

Command Modes

Command History

Task ID

Examples

default-route

Syntax Description

Command Default

Command Modes

Command History

Usage Guidelines

Task ID

Examples

Related Commands

default-vrf implicit-ipv4 disable

Command Default

Command Modes

Command History

Task ID

Examples

discovery hello

Syntax Description

Command Default