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The MPLS VPN Load Balancing Support for Inter-AS and CSC VPNs feature allows MPLS VPN interautonomous (Inter-AS) and MPLS VPN Carrier Supporting Carrier (CSC) networks to load share traffic between adjacent label switch routers (LSRs) that are connected by multiple links. The LSRs can be a pair of Autonomous System Boundary Routers (ASBRs) or a CSC-provider edge (PE) and a CSC-customer edge (CE) device. Using directly connected loopback peering allows load sharing at the Interior Gateway Protocol (IGP) level so only one Border Gateway Protocol (BGP) session is needed between the LSRs. No other label distribution mechanism is needed between the adjacent LSRs except BGP.
Ensure that your Multiprotocol Label Switching (MPLS) virtual private network (VPN) network, including MPLS VPN interautonomous system (Inter-AS) or Carrier Supporting Carrier (CSC), is configured and working properly.
Load sharing using directly connected loopback peering does not apply to Carrier Supported Carrier (CSC) networks that use the Label Distribution Protocol (LDP) and an Interior Gateway Protocol (IGP) to distribute routes and Multiprotocol Label Switching (MPLS) labels.
The software does not support load balancing in interautonomous system (Inter-AS) and CSC when there are multiple links between provider edge (PE) or Autonomous System Boundary Router (ASBR) devices.
When you configure static routes in an MPLS or MPLS virtual private network (VPN) environment, some variations of the ip route and ip route vrf commands are not supported. These variations of the commands are not supported in Cisco software releases that support the Tag Forwarding Information Base (TFIB. The TFIB cannot resolve prefixes when the recursive route over which the prefixes travel disappears and then reappears. However, the command variations are supported in Cisco software releases that support the MPLS Forwarding Infrastructure (MFI). Use the following guidelines when configuring static routes.
The following ip route command is supported when you configure static routes in an MPLS environment:
ip route destination-prefix mask interface next-hop-address
The following ip route commands are supported when you configure static routes in an MPLS environment and configure load sharing with static nonrecursive routes and a specific outbound interface:
ip route destination-prefix mask interface1 next-hop1
ip route destination-prefix mask interface2 next-hop2
The following ip route command is not supported when you configure static routes in an MPLS environment:
ip route destination-prefix mask next-hop-address
The following ip route command is not supported when you configure static routes in an MPLS VPN environment and enable load sharing where the next hop can be reached through two paths:
ip route destination-prefix mask next-hop-address
The following ip route command is not supported when you configure static routes in an MPLS VPN environment and enable load sharing where the destination can be reached through two next hops:
ip route destination-prefix mask next-hop1
ip route destination-prefix mask next-hop2
Use the interface and next-hop arguments when specifying static routes.
The following ip route vrf commands are supported when you configure static routes in an MPLS VPN environment, and the next hop and interface are associated with the same virtual routing and forwarding (VRF) instance:
ip route vrf vrf-name destination-prefix mask next-hop-address
ip route vrf vrf-name destination-prefix mask interface next-hop-address
ip route vrf vrf-name destination-prefix mask interface1 next-hop1
ip route vrf vrf-name destination-prefix mask interface2 next-hop2
The following ip route vrf commands are supported when you configure static routes in an MPLS VPN environment, and the next hop is in the global table in the MPLS cloud in the global routing table. For example, these commands are supported when the next hop is pointing to the internet gateway.
ip route vrf vrf-name destination-prefix mask next-hop-address global
ip route vrf vrf-name destination-prefix mask interface next-hop-address (This command is supported when the next hop and the interface are in the core.)
The following ip route commands are supported when you configure static routes in an MPLS VPN environment and enable load sharing with static nonrecursive routes and a specific outbound interfaces:
ip route destination-prefix mask interface1 next-hop1
ip route destination-prefix mask interface2 next-hop2
The following ip route command is not supported when you configure static routes in an MPLS VPN environment, the next hop is in the global table in the MPLS cloud within the core, and you enable load sharing where the next hop can be reached through two paths:
ip route vrf destination-prefix mask next-hop-address global
The following ip route commands are not supported when you configure static routes in an MPLS VPN environment, the next hop is in the global table in the MPLS cloud within the core, and you enable load sharing where the destination can be reached through two next hops:
ip route vrf destination-prefix mask next-hop1 global
ip route vrf destination-prefix mask next-hop2 global
The following ip route vrf commands are not supported when you configure static routes in an MPLS VPN environment, and the next hop and interface are in the same VRF:
ip route vrf vrf-name destination-prefix mask next-hop1
ip route vrf vrf-name destination-prefix mask next-hop2
The following ip route vrf command is supported when you configure static routes in an MPLS VPN environment, and the next hop is in the global table on the customer edge (CE) side. For example, the following command is supported when the destination-prefix is the CE device’s loopback address, as in external Border Gateway Protocol (eBGP) multihop cases.
ip route vrf vrf-name destination-prefix mask interface next-hop-address
The following ip route commands are supported when you configure static routes in an MPLS VPN environment, the next hop is in the global table on the CE side, and you enable load sharing with static nonrecursive routes and a specific outbound interfaces:
ip route destination-prefix mask interface1 nexthop1
ip route destination-prefix mask interface2 nexthop2
You use the MPLS VPN Load Balancing Support for Inter-AS and CSC VPN feature to load share traffic between adjacent label switched routers (LSRs) that are connected by multiple links. The LSRs could be a pair of Autonomous System Boundary Routers (ASBRs) or a carrier supporting carrier provider edge (CSC-PE) and a CSC-customer edge (CE).
Using directly connected loopback peering allows load sharing at the Interior Gateway Protocol (IGP) level so only one Border Gateway Protocol (BGP) session is needed between the LSRs. No other label distribution mechanism is needed between the adjacent LSRs except BGP.
Directly connected loopback peering enables load sharing of traffic as follows:
A BGP session is established, using the loopback addresses of the LSRs.
Multiprotocol Label Switching (MPLS) is enabled on the connecting links.
Multiple static routes to the loopback address of the adjacent LSR allow IGP load sharing.
The outgoing label to the loopback address of the adjacent LSR is an implicit null label and is inferred by the LSR.
Because IGP load sharing is enabled on the loopback address of the adjacent LSR, any traffic destined to a prefix that is learned over the BGP session (and recurses over the loopback) is load shared.
This section describes the following tasks you need to do to configure peering of loopback interfaces of directly connected Autonomous System Boundary Routers (ASBRs):
The figure below shows the loopback configuration for directly connected ASBR1 and ASBR2. This configuration is used as the example in the tasks that follow.
Perform this task to configure loopback interface addresses for directly connected Autonomous System Boundary Routers (ASBRs).
 Note |
Loopback addresses need to be configured for each directly connected ASBR. That is, configure a loopback address for ASBR1 and for ASBR2 in the example shown in the figure above. |
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
enable Example: |
Enables privileged EXEC mode.
|
|
Step 2 |
configure terminal Example: |
Enters global configuration mode. |
|
Step 3 |
interface loopback interface- number Example: |
Configures a software-only virtual interface that emulates an interface that is always up and enters interface configuration mode.
|
|
Step 4 |
ip address ip-address mask [secondary] Example: |
Sets a primary or secondary IP address for an interface.
|
|
Step 5 |
end Example: |
Exits to privileged EXEC mode. |
Perform this task to configure /32 static routes to the external Border Gateway Protocol (eBGP) neighbor loopback.
Note |
You need to configure /32 static routes on each of the directly connected ASBRs. |
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
enable Example: |
Enables privileged EXEC mode.
|
|
Step 2 |
configure terminal Example: |
Enters global configuration mode. |
|
Step 3 |
ip route prefix mask {ip-address | interface-type interface-number [ip-address]} [distance] [name] [permanent] [tag tag] Example: |
Establishes static routes.
|
|
Step 4 |
end Example: |
Exits to privileged EXEC mode. |
Perform this task to configure forwarding on the connecting loopback interfaces.
This task is required for sessions between loopbacks. In the “Configuring /32 Static Routes to the eBGP Neighbor Loopback" section, Ethernet 1/0 and Ethernet 0/0 are the connecting interfaces.
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
enable Example: |
Enables privileged EXEC mode.
|
|
Step 2 |
configure terminal Example: |
Enters global configuration mode. |
|
Step 3 |
interface type slot/port Example: |
Configures an interface type and enters interface configuration mode.
|
|
Step 4 |
mpls bgp forwarding Example: |
Configures the Border Gateway Protocol (BGP) to enable Multiprotocol Label Switching (MPLS) forwarding on connecting interfaces. |
|
Step 5 |
exit Example: |
Exits to global configuration mode. |
|
Step 6 |
Repeat Steps 3 and 4 for another connecting interface (Ethernet 0/0). |
|
|
Step 7 |
end Example: |
Exits to privileged EXEC mode. |
Perform this task to configure an external Border Gateway Protocol (eBGP) session between the loopbacks.
Note |
You need to configure an eBGP session between loopbacks on each directly connected Autonomous System Boundary Router (ASBR). |
| Command or Action | Purpose | |||
|---|---|---|---|---|
|
Step 1 |
enable Example: |
Enables privileged EXEC mode.
|
||
|
Step 2 |
configure terminal Example: |
Enters global configuration mode. |
||
|
Step 3 |
router bgp as-number Example: |
Configures the BGP routing process.
|
||
|
Step 4 |
no bgp default route-target filter Example: |
Disables BGP route-target filtering, and enters router configuration mode.
|
||
|
Step 5 |
neighbor {ip-address | peer-group-name} remote-as as-number Example: |
Adds an entry to the BGP or multiprotocol BGP neighbor table.
|
||
|
Step 6 |
neighbor {ip-address | peer-group-name} disable-connected-check Example: |
Allows peering between loopbacks.
|
||
|
Step 7 |
neighbor {ip-address | ipv6-address | peer-group-name} update-source interface-type interface-number Example: |
Allows BGP sessions to use any operational interface for TCP connections.
This argument must be in the form documented in RFC 2373, where the address is specified in hexadecimal using 16-bit values between colons.
|
||
|
Step 8 |
address-family vpnv4 [unicast] Example: |
Enters address family configuration mode for configuring routing protocols such as BGP, Routing Information Protocol (RIP), and static routing.
|
||
|
Step 9 |
neighbor {ip-address | peer-group-name | ipv6-address} activate Example: |
Enables the exchange of information with a BGP neighbor.
|
||
|
Step 10 |
neighbor {ip-address | peer-group-name} send-community [both | standard extended] Example: |
Specifies that a communities attribute should be sent to a BGP neighbor.
|
||
|
Step 11 |
end Example: |
Exits to privileged EXEC mode. |
Perform this task to verify that load sharing occurs between loopbacks. You need to ensure that the Multiprotocol Label Switching (MPLS) Label Forwarding Information Base (LFIB) entry for the neighbor route lists the available paths and interfaces.
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
enable Example: |
(Optional) Enables privileged EXEC mode.
|
|
Step 2 |
show mpls forwarding-table {mask | length} | labels label [network label] | interface interface | next-hop address | lsp-tunnel [tunnel-id]] [vrf vrf-name] [detail] Example: |
Displays the contents of the MPLS LFIB.
|
|
Step 3 |
disable Example: |
Exits to user EXEC mode. |
The following sections describe how to configure peering of loopback interfaces of directly connected Autonomous System Boundary Routers (ASBRs) to achieve load sharing in an interautonomous system network:
The figure below shows the loopback configuration for directly connected ASBR1 and ASBR2. This configuration is used as the example in the tasks that follow.
Note |
Loopback addresses need to be configured for each directly connected Autonomous System Boundary Router (ASBR). That is, configure a loopback address for ASBR1 and for ASBR2 as in the example shown in the figure above. |
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
enable Example: |
Enables privileged EXEC mode.
|
|
Step 2 |
configure terminal Example: |
Enters global configuration mode. |
|
Step 3 |
interface loopback interface number Example: |
Configures a software-only virtual interface that emulates an interface that is always up and enters interface configuration mode.
|
|
Step 4 |
ip address ip-address [mask [secondary]] Example: |
Sets a primary or secondary IP address for an interface.
|
|
Step 5 |
end Example: |
Exits to privileged EXEC mode. |
Perform this task to configure /32 static routes to the external Border Gateway Protocol (eBGP) neighbor loopback.
Note |
You need to configure /32 static routes on each of the directly connected Autonomous System Boundary Routers (ASBRs). |
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
enable Example: |
Enables privileged EXEC mode.
|
|
Step 2 |
configure terminal Example: |
Enters global configuration mode. |
|
Step 3 |
ip route prefix mask {ip-address | interface-type interface-number [ip-address]} [distance] [name] [permanent] [tag tag] Example: |
Establishes static routes.
|
|
Step 4 |
end Example: |
Exits to privileged EXEC mode. |
This task is required for sessions between loopbacks. In the “Configuring /32 Static Routes to the eBGP Neighbor Loopback” task, Ethernet1/0 and Ethernet0/0 are the connecting interfaces.
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
enable Example: |
Enables privileged EXEC mode.
|
|
Step 2 |
configure terminal Example: |
Enters global configuration mode. |
|
Step 3 |
interface type slot/port Example: |
Configures an interface type and enters interface configuration mode.
|
|
Step 4 |
mpls bgp forwarding Example: |
Configures BGP to enable MPLS forwarding on connecting interfaces. |
|
Step 5 |
exit Example: |
Exits to global configuration mode. |
|
Step 6 |
Repeat Steps 3 and 4 for another connecting interface (Ethernet 0/0). |
|
|
Step 7 |
end Example: |
Exits to privileged EXEC mode. |
Note |
You need to configure an external Border Gateway Protocol (eBGP) session between loopbacks on each directly connected Autonomous System Boundary Router (ASBR). |
| Command or Action | Purpose | |||
|---|---|---|---|---|
|
Step 1 |
enable Example: |
Enables privileged EXEC mode.
|
||
|
Step 2 |
configure terminal Example: |
Enters global configuration mode. |
||
|
Step 3 |
router bgp as-number Example: |
Configures the BGP routing process, and enters router configuration mode.
|
||
|
Step 4 |
bgp log-neighbor-changes Example: |
Enables logging of BGP neighbor resets. |
||
|
Step 5 |
neighbor {ip-address | peer-group-name} remote-as as-number Example: |
Adds an entry to the BGP or multiprotocol BGP neighbor table.
|
||
|
Step 6 |
neighbor {ip-address | peer-group-name} disable-connected-check Example: |
Allows peering between loopbacks.
|
||
|
Step 7 |
neighbor {ip-address | peer-group-name} ebgp-multihop [ttl] Example: |
Accepts and attempts BGP connections to external peers residing on networks that are not directly connected.
|
||
|
Step 8 |
neighbor {ip-address | ipv6-address | peer-group-name} update-source interface-type interface-number Example: |
Allows BGP sessions to use any operational interface for TCP connections.
|
||
|
Step 9 |
address-family ipv4 [unicast] vrf vrf-name Example: |
Enters address family configuration mode for configuring routing protocols such as BGP, Routing Information Protocol (RIP), and static routing.
|
||
|
Step 10 |
neighbor {ip-address | peer-group-name | ipv6-address} activate Example: |
Enables the exchange of information with a BGP neighbor.
|
||
|
Step 11 |
neighbor {ip-address | peer-group-name} send-community [both | standard | extended Example: |
Specifies that a communities attribute should be sent to a BGP neighbor.
|
||
|
Step 12 |
end Example: |
Exits to privileged EXEC mode. |
To verify that load sharing can occur between loopbacks, ensure that the Multiprotocol Label Switching (MPLS) Label Forwarding Information Base (LFIB) entry for the neighbor route lists the available paths and interfaces.
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
enable Example: |
Enables privileged EXEC mode.
|
|
Step 2 |
show mpls forwarding-table [network {mask |length} | labels label [label ] | interface interface | next-hop address | lsp-tunnel [tunnel-id]] [vrf vrf-name ] [detail ] Example: |
Displays the contents of the MPLS LFIB.
|
|
Step 3 |
disable Example: |
Exits to user EXEC mode. |
The following sections explain how to load balance Carrier Supporting Carrier (CSC) traffic by peering loopback interfaces of directly connected CSC-provider edge (PE) and CSC-customer edge (CE) devices:
The figure below shows the loopback configuration for directly connected CSC-PE and CSC-CE devices. This configuration is used as the example in the tasks that follow.
Note |
Configuration of a loopback interface address on the Carrier Supporting Carrier (CSC)-provider edge (PE) device requires the enabling of a virtual routing and forwarding (VRF) instance. The CSC-customer edge (CE) device loopback interface does not require enabling a VRF. |
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
enable Example: |
Enables privileged EXEC mode.
|
|
Step 2 |
configure terminal Example: |
Enters global configuration mode. |
|
Step 3 |
interface loopback interface number Example: |
Configures a software-only virtual interface that emulates an interface that is always up, and enters interface configuration mode.
|
|
Step 4 |
ip vrf forwarding vrf-name Example: |
Associates a VRF with the specified interface or subinterface.
|
|
Step 5 |
ip address ip-address mask [secondary] Example: |
Sets a primary or secondary IP address for an interface.
|
|
Step 6 |
end Example: |
Exits to privileged EXEC mode. |
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
enable Example: |
Enables privileged EXEC mode.
|
|
Step 2 |
configure terminal Example: |
Enters global configuration mode. |
|
Step 3 |
interface loopback interface-number Example: |
Configures a software-only virtual interface that emulates an interface that is always up.
|
|
Step 4 |
ip address ip-address mask [secondary] Example: |
Sets a primary or secondary IP address for an interface.
|
|
Step 5 |
end Example: |
Exits to privileged EXEC mode. |
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
enable Example: |
Enables privileged EXEC mode.
|
|
Step 2 |
configure terminal Example: |
Enters global configuration mode. |
|
Step 3 |
ip route vrf vrf-name prefix mask {ip-address | interface-type interface-number [ip-address]} [global] [distance] [name] [permanent] [tag tag] Example: |
Establishes static routes for a virtual routing and forwarding (VRF) instance.
|
|
Step 4 |
end Example: |
Exits to privileged EXEC mode. |
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
enable Example: |
Enables privileged EXEC mode.
|
|
Step 2 |
configure terminal Example: |
Enters global configuration mode. |
|
Step 3 |
ip route prefix mask {ip-address | interface-type interface-number [ip-address]} [distance] [name] [permanent] [tag tag] Example: |
Establishes static routes.
|
|
Step 4 |
end Example: |
Exits to privileged EXEC mode. |
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
enable Example: |
Enables privileged EXEC mode.
|
|
Step 2 |
configure terminal Example: |
Enters global configuration mode. |
|
Step 3 |
interface type slot/port Example: |
Configures an interface type and enters interface configuration mode.
|
|
Step 4 |
ip vrf forwarding vrf-name Example: |
Associates a virtual routing and forwarding (VRF) instance with an interface or subinterface.
|
|
Step 5 |
ip address ip-address mask [secondary] Example: |
Sets a primary or secondary IP address for an interface.
|
|
Step 6 |
mpls bgp forwarding Example: |
Configures the Border Gateway Protocol (BGP) to enable Multiprotocol Label Switching (MPLS) forwarding on connecting interfaces. |
|
Step 7 |
exit Example: |
Exits to global configuration mode. |
|
Step 8 |
Repeat Steps 3 through 6 for another connecting interface (Ethernet 0/0). |
|
|
Step 9 |
end Example: |
Exits to privileged EXEC mode. |
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
enable Example: |
Enables privileged EXEC mode.
|
|
Step 2 |
configure terminal Example: |
Enters global configuration mode. |
|
Step 3 |
interface typeslot/port Example: |
Configures an interface type and enters interface configuration mode.
|
|
Step 4 |
mpls bgp forwarding Example: |
Configures the Border Gateway Protocol (BGP) to enable Multiprotocol Label Switching (MPLS) forwarding on connecting interfaces. |
|
Step 5 |
exit Example: |
Exits to global configuration mode. |
|
Step 6 |
Repeat Steps 3 and 4 for another connecting interface (Ethernet 0/0). |
|
|
Step 7 |
end Example: |
Exits to privileged EXEC mode. |
| Command or Action | Purpose | |||
|---|---|---|---|---|
|
Step 1 |
enable Example: |
Enables privileged EXEC mode.
|
||
|
Step 2 |
configure terminal Example: |
Enters global configuration mode. |
||
|
Step 3 |
router bgp as-number Example: |
Configures the Border Gateway Protocol (BGP) routing process.
|
||
|
Step 4 |
bgp log-neighbor-changes Example: |
Enables logging of BGP neighbor resets. |
||
|
Step 5 |
neighbor {ip-address | peer-group-name} remote-as as-number Example: |
Adds an entry to the BGP or multiprotocol BGP neighbor table.
|
||
|
Step 6 |
neighbor {ip-address | peer-group-name} disable-connected-check Example: |
Allows peering between loopbacks.
|
||
|
Step 7 |
neighbor {ip-address | ipv6-address | peer-group-name} update-source interface-type interface-number Example: |
Allows BGP sessions to use any operational interface for TCP connections.
This argument must be in the form documented in RFC 2373, where the address is specified in hexadecimal using 16-bit values between colons.
|
||
|
Step 8 |
address-family ipv4 [unicast] vrf vrf-name Example: |
Enters address family configuration mode for configuring routing protocols such as BGP, Routing Information Protocol (RIP), and static routing.
|
||
|
Step 9 |
ip vrf forwarding vrf-name Example: |
Associates a VRF with an interface or subinterface.
|
||
|
Step 10 |
neighbor {ip-address | peer-group-name | ipv6-address} activate Example: |
Enables the exchange of information with a BGP neighbor.
|
||
|
Step 11 |
neighbor ip-address send-label Example: |
Enables a BGP device to send MPLS labels with BGP routes to a neighboring BGP device.
|
||
|
Step 12 |
end Example: |
Exits to privileged EXEC mode. |
| Command or Action | Purpose | |||
|---|---|---|---|---|
|
Step 1 |
enable Example: |
Enables privileged EXEC mode.
|
||
|
Step 2 |
configure terminal Example: |
Enters global configuration mode. |
||
|
Step 3 |
router bgp as-number Example: |
Configures the Border Gateway Protocol (BGP) routing process.
|
||
|
Step 4 |
bgp log-neighbor-changes Example: |
Enables logging of BGP neighbor resets. |
||
|
Step 5 |
neighbor {ip-address | peer-group-name} remote-as as-number Example: |
Adds an entry to the BGP or multiprotocol BGP neighbor table.
|
||
|
Step 6 |
neighbor {ip-address | peer-group-name} disable-connected-check Example: |
Allows peering between loopbacks.
|
||
|
Step 7 |
neighbor {ip-address | ipv6-address | peer-group-name} update-source interface-type interface-number Example: |
Allows BGP sessions to use any operational interface for TCP connections.
This argument must be in the form documented in RFC 2373, where the address is specified in hexadecimal using 16-bit values between colons.
|
||
|
Step 8 |
address-family ipv4 [unicast] [vrf vrf-name] Example: |
Enters address family configuration mode for configuring routing protocols such as BGP, RIP, and static routing.
|
||
|
Step 9 |
neighbor {ip-address | peer-group-name|ipv6-address] activate Example: |
Enables the exchange of information with a BGP neighbor.
|
||
|
Step 10 |
neighbor ip-address send-label Example: |
Enables a BGP device to send Multiprotocol Label Switching (MPLS) labels with BGP routes to a neighboring BGP device.
|
||
|
Step 11 |
end Example: |
Exits to privileged EXEC mode. |
To verify that load sharing occurs between loopbacks, ensure that the Multiprotocol Label Switching (MPLS) Label Forwarding Information Base (LFIB) entry for the neighbor route lists the available paths and interfaces.
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
enable Example: |
Enables privileged EXEC mode.
|
|
Step 2 |
show mpls forwarding-table [vrf vrf-name ] [{network {mask | length } | labels label [-label ] | [ interface ] interface | next-hop address | lsp-tunnel [tunnel-id ]}] [detail ] Example: |
Displays the contents of the MPLS LFIB. |
|
Step 3 |
disable Example: |
Exits to user EXEC mode. |
The following example configures a /32 static route from ASBR1 to the loopback address of ASBR2:
Device# configure terminal
Device(config)# ip route 10.20.20.20 255.255.255 e1/0 168.192.0.1
Device(config)# ip route 10.20.20.20 255.255.255 e0/0 168.192.2.1
The following example configures a /32 static route from ASBR2 to the loopback address of ASBR1:
Device# configure terminal
Device(config)# ip route vrf vpn1 10.10.10.10 255.255.255 e1/0 168.192.0.2
Device(config)# ip route vrf vpn1 10.10.10.10 255.255.255 e0/0 168.192.2.2
The following example configures the Border Gateway Protocol (BGP) and Multiprotocol Label Switching (MPLS) forwarding on the interfaces connecting ASBR2 with ASBR1:
Device# configure terminal
Device(config)# interface ethernet 1/0
Device(config-if)# ip vrf forwarding vpn1
Device(config-if)# ip address 168.192.0.1 255.255.255.255
Device(config-if)# mpls bgp forwarding
Device(config-if)# exit
Device(config)# interface ethernet 0/0
Device(config-if)# ip vrf forwarding vpn1
Device(config-if)# ip address 168.192.2.1 255.255.255.255
Device(config-if)# mpls bgp forwarding
Device(config-if)# exit
The following example configures VPNv4 sessions on ASBR2:
Device# configure terminal
Device(config)# router bgp 200
Device(config-router)# bgp log-neighbor-changes
Device(config-router)# neighbor 10.10.10.10 remote-as 100
Device(config-router)# neighbor 10.10.10.10 disable-connected-check
Device(config-router)# neighbor bb.bb.bb.bb ebgp-multihop 255
Device(config-router)# neighbor 10.10.10.10 update-source Loopback0
!
Device(config-router)# address-family vpnv4
Device(config-router-af)# neighbor 10.10.10.10 activate
Device(config-router-af)# neighbor 10.10.10.10 send-community extended
Device(config-router-af)# end
|
Related Topic |
Document Title |
|---|---|
|
Cisco IOS commands |
|
|
MPLS commands |
|
|
Configuring MPLS VPN CSC with BGP |
“MPLS VPN Carrier Supporting Carrier with BGP” module in the MPLS: Layer 3 VPNs: Inter-AS and CSC Configuration Guide |
|
Configuring BGP |
“Configuring BGP” module in the IP Routing: BGP Configuration Guide |
|
Configuring BGP Multipath Load Sharing for Both eBGP and iBGP in an MPLS VPN |
“BGP Multipath Load Sharing for Both eBGP and iBGP in an MPLS VPN” module in the IP Routing: BGP Configuration Guide |
|
RFC |
Title |
|---|---|
|
RFC 1164 |
Application of the Border Gateway Protocol in the Internet |
|
RFC 1171 |
A Border Gateway Protocol 4 |
|
RFC 1700 |
Assigned Numbers |
|
RFC 1966 |
BGP Route Reflection: An Alternative to Full Mesh IBGP |
|
RFC 2283 |
Multiprotocol Extensions for BGP-4 |
|
RFC 2373 |
IP Version 6 Addressing Architecture |
|
RFC 2547 |
BGP/MPLS VPNs |
|
RFC 2842 |
Capabilities Advertisement with BGP-4 |
|
RFC 2858 |
Multiprotocol Extensions for BGP-4 |
|
RFC 3107 |
Carrying Label Information in BGP-4 |
|
Description |
Link |
|---|---|
|
The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password. |
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.|
Feature Name |
Releases |
Feature Information |
|---|---|---|
|
MPLS VPN Load Balancing Support for Inter-AS and CSC VPNs |
12.0(29)S 12.4(20)T 12.2(33)SRA 12.2(33)SXH Cisco IOS XE Release 2.2 |
The MPLS VPN Load Balancing Support for Inter-AS and CSC VPNs feature allows MPLS VPN Inter-AS and MPLS VPN CSC networks to load share traffic between adjacent LSRs that are connected by multiple links. The LSRs can be a pair of ASBRs or a CSC-PE and a CSC-CE. Using directly connected loopback peering allows load sharing at the IGP level, so more than one BGP session is not needed between the LSRs. No other label distribution mechanism is needed between the adjacent LSRs than BGP. In Cisco IOS Release 12.0(29)S, this feature was introduced. In Cisco IOS Release 12.4(20)T, 12.2(33)SRA, and 12.2(33)SXH, this feature was integrated. In Cisco IOS XE Release 2.2, this feature was implemented on the Cisco ASR 1000 Series Routers. No commands were introduced or modified. |
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