Table Of Contents
Cisco IOS Software Modularity: MPLS Layer 3 VPNs
Prerequisites for Cisco IOS Software Modularity: MPLS Layer 3 VPNs
Restrictions for Cisco IOS Software Modularity: MPLS Layer 3 VPNs
Information About Cisco IOS Software Modularity: MPLS Layer 3 VPNs
Introduction to the Cisco IOS Software Modularity: MPLS Layer 3 VPNs Feature
Cisco IOS Software Modularity and High Availability
How Cisco IOS Software Modularity Processes Work with Software That Is Not Modular
MPLS Traffic Engineering and RSVP-TE Messages
How Processes Are Restarted on Cisco IOS Software Modularity: MPLS Layer 3 VPNs
How Patching Works on Cisco IOS Software Modularity: MPLS Layer 3 VPNs
CLI Changes Due to the Cisco IOS Software Modularity: Layer 3 VPNs Feature
debug mpls traffic-eng process-restart
show mpls traffic-eng link-management advertisements
show mpls traffic-eng link-management summary
show mpls traffic-eng process-restart iprouting
Feature Information for Cisco IOS Software Modularity: MPLS Layer 3 VPNs
Cisco IOS Software Modularity: MPLS Layer 3 VPNs
First Published: May 31, 2007Last Updated: May 31, 2007In Cisco IOS Release 12.2(33)SXH, the Cisco IOS Software Modularity feature has been extended to include Multiprotocol Label Switching (MPLS) Virtual Private Networks (VPNs). Through software infrastructure enhancements, the Cisco IOS Software Modularity: MPLS Layer 3 VPNs feature reduces both planned and unplanned downtime and boosts operational efficiency. You can restart, upgrade, and patch modularized components and processes without interrupting service.
Identifying and fixing faults and failures is also easier, because you can isolate components and processes. The software modularity capabilities integrate with and make use of High Availability (HA) features already in place.
Finding Feature Information in This Module
Your Cisco IOS software release may not support all of the features documented in this module. To reach links to specific feature documentation in this module and to see a list of the releases in which each feature is supported, use the "Feature Information for Cisco IOS Software Modularity: MPLS Layer 3 VPNs" section.
Finding Support Information for Platforms and Cisco IOS and Catalyst OS Software Images
Use Cisco Feature Navigator to find information about platform support and Cisco IOS and Catalyst OS software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Contents
•Prerequisites for Cisco IOS Software Modularity: MPLS Layer 3 VPNs
•Restrictions for Cisco IOS Software Modularity: MPLS Layer 3 VPNs
•Information About Cisco IOS Software Modularity: MPLS Layer 3 VPNs
•Feature Information for Cisco IOS Software Modularity: MPLS Layer 3 VPNs
Prerequisites for Cisco IOS Software Modularity: MPLS Layer 3 VPNs
The following are prerequisites for the Cisco IOS Software Modularity: MPLS Layer 3 VPNs feature:
•Before implementing the Cisco IOS Software Modularity: MPLS Layer 3 VPN feature, you should understand the concepts and tasks related to Cisco IOS Software Modularity. See the Cisco IOS Software Modularity Installation and Configuration Guide.
•The Cisco IOS Software Modularity: MPLS Layer 3: VPNs feature works with the MPLS HA features. See the following MPLS HA documentation for information about configuring MPLS HA:
–MPLS High Availability: Overview
–NSF/SSO: MPLS LDP and LDP Graceful Restart
–NSF/SSO: Any Transport over MPLS and AToM Graceful Restart
–MPLS High Availability: Command Changes
–Cisco Express Forwarding: Command Changes
–NSF/SSO—MPLS TE and RSVP Graceful Restart
Restrictions for Cisco IOS Software Modularity: MPLS Layer 3 VPNs
•The software components that make up MPLS Layer 3 VPNs—that is, routing protocols, the master virtual routing and forwarding (VRF) database, and the Routing Information Bases (RIBs) for IPv4 and IPv6—were rewritten to work with the Cisco IOS software modularity infrastructure. The software modularity changes included moving the MPLS Layer 3 VPN infrastructure to the restartable routing process. However, other MPLS components, such as the MPLS Forwarding Information Base (FIB), Label Distribution Protocol (LDP), and traffic engineering (TE) have not been rewritten to conform with Cisco IOS software modularity. As a result, those components run in processes that cannot be restarted in the event of an error.
•This Cisco IOS Software Modularity: MPLS Layer 3: VPNs feature is supported on Cisco Catalyst 6500 series switches.
•You can patch and restart the MPLS Layer 3 VPN software without service disruptions. However, you cannot patch and restart without service disruption other MPLS components that are not compliant with the software modularity infrastructure.
•The Cisco IOS Software Modularity: MPLS Layer 3: VPNs feature uses 10 to 20 percent more memory than the Cisco IOS software without software modularity. For guidelines on memory requirements for modularization features, see the Cisco IOS Software Modularity Installation and Configuration Guide.
•The Cisco IOS Software Modularity: MPLS Layer 3: VPNs feature minimally reduces the number of targeted LDP sessions you can have. It also slightly increases tunnel setup times and marginally reduces convergence times.
For information on performance factors, see the "Best Practices for Scalability and Convergence in the Cisco IOS Software Modularity: MPLS Layer 3 VPNs Feature" section.
Information About Cisco IOS Software Modularity: MPLS Layer 3 VPNs
To use the Cisco IOS Software Modularity: MPLS Layer 3 VPNs feature, you should understand the following concepts:
•Introduction to the Cisco IOS Software Modularity: MPLS Layer 3 VPNs Feature
•Cisco IOS Software Modularity and High Availability
•How Cisco IOS Software Modularity Processes Work with Software That Is Not Modular
•How Processes Are Restarted on Cisco IOS Software Modularity: MPLS Layer 3 VPNs
•How Patching Works on Cisco IOS Software Modularity: MPLS Layer 3 VPNs
•CLI Changes Due to the Cisco IOS Software Modularity: Layer 3 VPNs Feature
Introduction to the Cisco IOS Software Modularity: MPLS Layer 3 VPNs Feature
Cisco IOS Software Modularity code is partitioned into multiple processes that run in their own protected memory space and that can independently restart. The control plane components for the Layer 3 VPNs moved from the tightly coupled and interdependent Cisco IOS code to the restartable routing process.
Some of the Cisco IOS modular processes that MPLS uses include:
•TCP is a separate restartable process that is important to MPLS because Border Gateway Protocol (BGP) and LDP sessions run over TCP connections.
•Routing is a restartable process that contains the following control plane components:
–Open Shortest Path First (OSPF)
–Intermediate System-to-Intermediate System (IS-IS)
–BGP
–RIB
–Layer 3 VPN control plane components
•User Datagram Protocol (UDP) is a restartable process that is important for MPLS because LDP hello messages are transmitted in UDP packets. Further, MPLS embedded management applications may use UDP packets to transmit data.
Cisco IOS software includes more than 37 other modular processes so that restarts in the control plane components do not affect the transmission of data in the forwarding plane.
MPLS components that have not been made modular include:
•IP FIB
•MPLS Forwarding Infrastructure (MFI)
•Other MPLS control plane components, including LDP, Resource Reservation Protocol-traffic engineering (RSVP-TE), and IP Rewrite Manager (IPRM).
If an error occurs in one of those software components, the transmission of data is interrupted.
Cisco IOS Software Modularity and High Availability
Unplanned downtime can be caused by software or hardware faults, such as control plane errors, control processor or line card failures. Most unplanned down time is caused by software faults related to the control plane.
To reduce unplanned downtime, Cisco IOS HA, nonstop forwarding (NSF) and stateful switchover (SSO) features work with routers that have primary and backup Route Processors (RPs). The following MPLS features are highly available through NSF and SSO:
•MPLS VPNs
•MPLS LDP
•MPLS TE and RSVP
With NSF and SSO, the primary and backup RPs keep identical copies of the label and state information by checkpointing. Checkpointing is a function that copies state information from the active RP to the backup RP, thereby ensuring that the backup has the latest information. If a control plane error causes the primary RP to fail, the backup RP takes over without disrupting the forwarding plane. This enables MPLS VPN, LDP, and TE features to keep running during a switchover.
Cisco IOS software modularity improves on the HA functionality by applying NSF and SSO to individual processes running within the Cisco IOS software. Cisco IOS software modularity provides the following improvements:
•For routers with a single RP, Cisco IOS software modularity enables individual processes to restart. If a process restarts successfully, it recovers its state either from a neighboring router that has Graceful Restart or from a database that checkpointed the state information. The process resumes normal operation without interrupting the forwarding plane. If the process cannot restart, the process is declared dead and the RP must be restarted.
•For routers with primary and backup RPs, Cisco IOS software modularity enables individual processes to restart. If the process cannot restart and is a mandatory process, the router switches to a backup RP, which takes over the processing without interruption.
To reduce unplanned downtime, enable the following HA features on the routers with Cisco IOS software modularity installed:
•SSO for routers with primary and backup RPs
•NSF for all supported routing protocols, that is, BGP, Enhanced Interior Routeway Gating Protocol (EIGRP), OSPF, and IS-IS
•GR for all MPLS features, that is, MPLS VPNs, MPLS LDP, MPLS TE, and RSVP
How Cisco IOS Software Modularity Processes Work with Software That Is Not Modular
The processes that have been made modular through Cisco IOS software modularity can fail and restart without interrupting the transmission of data in the forwarding plane. These modular processes are used within MPLS applications that have not been made modular, such as MPLS LDP and MPLS TE. The following sections explain the interactions between the MPLS applications and the modular processes.
MPLS LDP
MPLS LDP uses UDP to transmit LDP hello messages to discover neighbors and uses TCP to establish LDP sessions and exchange LDP label-binding information. Both TCP and UDP are modular processes.
If LDP is protected by GR functionality, when a TCP process fails the following events occur:
1. TCP is disconnected.
2. The LDP session is terminated.
3. LDP GR initiates and does the following:
•Saves LDP session information and marks it stale.
•Starts the reconnect timer, which indicates how long it will wait for the neighbor to reconnect.
•After the neighbor reconnects, it starts the recovery timer, which indicates how long it will wait for the neighbor to readvertise label-binding information.
4. If the TCP process restarts before the reconnect timer expires and LDP can establish a new session and complete an information exchange before the respective timer expires, the LDP GR process completes successfully.
If the TCP process does not restart before the reconnect timer expires, a restart of the RP is necessary.
If an LDP session has been protected by GR functionality, when a UDP process fails the following events occur:
1. If the UDP process restarts and LDP starts to exchange hello messages with neighbors before the LDP discovery hold timer expires, the LDP session continues without interruption.
2. If the UDP process does not restart before the LDP discovery hold timer expires, the LDP hello adjacency with the neighbor is torn down, which terminates the LDP session.
3. When the LDP session terminates, LDP GR initiates.
Note The MPLS LDP Session Protection feature works with the Cisco IOS Software Modularity feature, but cannot protect an LDP session if a UDP process fails.
MPLS Traffic Engineering
If you ensure that MPLS TE is configured with the NSF/SSO: MPLS TE and RSVP GR feature, MPLS TE can recover from a failure without disrupting the forwarding plane. See NSF/SSO: MPLS TE and RSVP Graceful Restart for more information.
The recovery behaviors of the failing RP and its neighboring RPs depend on the versions of Cisco IOS software running on the routers:
•Cisco IOS Release 12.0(29)S introduced the MPLS TE: RSVP GR feature, which allowed a router to assist a neighboring router that has SSO/NSF support and GR to recover gracefully from an interruption in service. In Cisco IOS Release 12.0(29)S, RSVP GR operates strictly in helper mode, which means it can help only other routers that are enabled with MPLS SSO/NSF and GR to recover. If the router running 12.0(29)S (or later 12.0S release) with RSVP GR fails, its peer routers cannot help it recover.
•Cisco IOS Release 12.2(33)SRA and later releases introduced SSO/NSF support for MPLS TE so that an RP can use failover techniques to recover from a disruption in control plane service without losing its MPLS forwarding state. The feature is called NSF/SSO: MPLS TE and RSVP GR.
•Cisco IOS Release 12.2(33)SXH also supports the NSF/SSO: MPLS TE and RSVP GR feature. Enabling this feature in the MPLS Cisco IOS software modularity environment ensures that MPLS TE can recover gracefully from control plane faults.
Routers running Cisco IOS Releases 12.2(33)SXH or 12.2(33)SRA or a later require the NSF/SSO: MPLS TE and RSVP GR feature to recover from a process restart or an SSO failover without disruption. All LSPs remain intact. If you do not enable the NSF/SSO: MPLS TE and RSVP GR feature, MPLS TE may encounter the following conditions:
•During an IP process restart, packets may be lost.
•During an SSO failover, the neighboring router tears down the LSPs to and through the router that has the SSO event.
Routers running the RSVP GR feature in Cisco IOS Release 12.0(29)S or later cannot exchange GR hello messages with routers running the NSF/SSO: MPLS TE and RSVP GR feature in Cisco IOS Releases 12.2(33)SXH, 12.2(33)SRA, or later releases. Those routers cannot assist a neighboring router during a process restart or SSO failover.
MPLS Traffic Engineering and RSVP-TE Messages
MPLS TE uses RSVP-TE extensions to explicitly route traffic over label switched paths. The RSVP-TE signaling protocol runs over IP. During an IP process restart, RSVP-TE messages can be dropped.
How Processes Are Restarted on Cisco IOS Software Modularity: MPLS Layer 3 VPNs
The restarting capability of the Cisco IOS Software Modularity: MPLS Layer 3 VPNs feature allows the restarting of any modular process, such as the IP routing process, while the rest of the system continues to operate normally.
The following sequence shows how a system can recover without any user interaction:
Note Assume that all routing protocols (control plane) have converged and that the forwarding plane is forwarding traffic. The routing protocols have been configured for NSF.
•The IP routing process fails.
•The routing protocols that have been configured with NSF reestablish sessions and exchange routing information as the IP routing process restarts. The forwarding plane continues to forward traffic without interruption.
•The IP routing process recovers and sends an NSF message to its neighbors indicating that it is recovering.
•NSF-aware neighbors keep the entries they learned from the recovering system in their tables and send their information back to the recovering system.
•When the control plane has processed all routing updates it received from its neighbors, it programs the changes to the data plane.
Forwarding on the data plane is being performed at all times during this sequence.
Generally users do not need to restart processes. The integrated HA constantly monitors all processes and automatically initiates a restart when needed.
How Patching Works on Cisco IOS Software Modularity: MPLS Layer 3 VPNs
The Cisco IOS Software Modularity: MPLS Layer 3 VPNs feature allows you to do selective system maintenance with individual patches. You can download, verify, install, and activate a patch for a component without restarting an entire system. Because patches affect only the component they are required to fix, they need less code-certification time than if an entire system had to be verified. You have to verify only the portion of software associated with the fix.
Best Practice for IP Routing Process Restarts with the Cisco IOS Software Modularity: MPLS Layer 3 VPNs Feature
Restarting the IP routing process restarts all the routing protocols and causes MPLS LDP to invoke the graceful restart routine. Wait until all the routing protocols have converged and LDP is back to a normal state before restarting the IP routing process again. Otherwise, traffic could be lost.
Best Practice for SSO/NSF on Peer Route Processors with Cisco IOS Software Modularity: MPLS Layer 3 VPNs Feature
See the NSF/SSO-MPLS VPN Guide for information on configuring MPLS VPN GR on peer RPs to ensure that routing and forwarding is not disrupted if there is a hardware failure on the primary RP.
Best Practices for Scalability and Convergence in the Cisco IOS Software Modularity: MPLS Layer 3 VPNs Feature
The Cisco IOS Software Modularity: MPLS Layer 3 VPNs feature is designed to have LDP and TE scalability and overall convergence values that are within 20 percent of comparable values in nonmodularized images. Routers that have enough memory to cover some 10 to 20 percent greater memory usage should not experience diminished performance.
See the Cisco IOS Software Modularity Installation and Configuration Guide, for guidelines on memory requirements for software modularization.
The following are the LDP and TE scalability and convergence effects:
•LDP scalability:
–The Cisco IOS Software Modularity: MPLS Layer 3 VPNs feature is very effective in reducing link flaps in link sessions.
–Images with the Cisco IOS Software Modularity: MPLS Layer 3 VPNs feature can scale to up to 900 targeted LDP sessions, compared to 1200 sessions on nonmodularized images.
•TE scalability:
–Tunnel setup times are longer and setup times increase as the number of tunnels increases but both times are within 20 percent of those on nonmodularized images.
•Convergence:
–Convergence times on images with the Cisco IOS Software Modularity: MPLS Layer 3 VPNs feature are within 20 percent of those on nonmodularized images.
CLI Changes Due to the Cisco IOS Software Modularity: Layer 3 VPNs Feature
The Cisco IOS Software Modularity: MPLS Layer 3 VPNs feature introduces the following two new commands:
•debug mpls traffic-eng process-restart
•show mpls traffic-eng process-restart iprouting
It modifies the following four commands.
•show ip route
•show mpls forwarding-table
•show mpls traffic-eng link-management advertisements
•show mpls traffic-eng link-management summary
New Commands
The show mpls traffic-eng process-restart iprouting command displays statistics about the resynchronization of the information shared between TE and the Internet Gateway Protocols after an IP routing process restart.
The debug mpls traffic-eng process-restart command displays messages related to the transfer of information between TE and the IGPs, and the resynchronization of this information, including the flushing of any stale information, after an IP Routing process restart.
See "Command Reference" section for more information on the new commands.
Modified Commands
The output of the show mpls traffic-eng link-management summary and the show mpls traffic-eng link-management advertisements commands are enhanced to show when an IP routing process restart is in progress.
The detailed output of the show ip route command (when you specify a prefix or mask) is enhanced to show remote label information and MPLS flags for prefixes that have a remote label stored in RIB. Remote MPLS labels used for forwarding that were formerly stored in IPRM working with BGP are now stored in RIB. This enhanced output can be used for troubleshooting.
The output of the show mpls forwarding-table command is enhanced to display troubleshooting information in the first column, Local Label, as follows:
•An [H] notation indicates local labels that are temporarily in holddown, that is, the application that requested the labels no longer needs them and stops advertising them to its labeling peers.
•A [T] notation indicates forwarding through a label switched path (LSP).
•An [HT] notation indicates that both conditions apply.
These outputs are shown whether or not users specify the detail or the internal keywords. You can use the detail or the internal keyword to display more information.
See the "Command Reference" section for more information on the modified commands.
Additional References
The following sections provide references related to the Cisco IOS Software Modularity: MPLS Layer 3 VPNs feature.
Related Documents
Related Topic Document TitleInstalling the Cisco IOS Software Modularity: MPLS Layer 3 VPNs feature
Cisco IOS Software Modularity Installation and Configuration Guide
High availability
Nonstop forwarding
High availability
Graceful restart
NSF/SSO: MPLS LDP and LDP Graceful Restart
NSF/SSO—MPLS TE and RSVP Graceful Restart
NSF/SSO: Any Transport over MPLS and AToM Graceful RestartExpress forwarding
Standards
Standard Titledraft-ietf-mpls-bgp-mpls-restart.txt
Graceful Restart Mechanism for BGP with MPLS
draft-ietf-mpls-idr-restart.txt
Graceful Restart Mechanism for BGP
MIBs
MIB MIBs Link•MPLS VPN MIB
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:
RFCs
RFC TitleRFC 1163
A Border Gateway Protocol
RFC 1164
Application of the Border Gateway Protocol in the Internet
RFC 2283
Multiprotocol Extensions for BGP-4
RFC 2547
BGP/MPLS VPNs
Technical Assistance
Command Reference
This section documents new and modified commands only.
New Commands
•debug mpls traffic-eng process-restart
•show mpls traffic-eng process-restart iprouting
Modified Commands
•show mpls traffic-eng link-management advertisements
•show mpls traffic-eng link-management summary
debug mpls traffic-eng process-restart
To display information about process restarts for reporting to your technical support representative, use the debug mpls traffic-eng process-restart command in privileged EXEC mode. To disable debugging output, use the no form of this command.
debug mpls traffic-eng process-restart
no debug mpls traffic-eng process-restart
Syntax Description
This command has no arguments or keywords.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
If you report a problem and the show mpls traffic-eng process-restart iprouting displays abnormal results, your technical support representative might ask you to issue the debug mpls traffic-eng process-restart command, then perform an IP routing process restart and capture the output for analysis.
Examples
The following example shows partial output from an IP routing process restart:
Router# debug mpls traffic-eng process-restart02:24:22: SM: ---TE ION Process Restart 0x78EF9050: process restart (3)02:24:22: SM: NORM (1) --> AWAIT-CFG (3)02:24:22: TE ION Restart timer started, proc_idx:0 delay:12000002:24:22: SM: ---TE ION Process Restart 0x78EF9050: process cfg replay start (4)02:24:22: SM: AWAIT-CFG (3) --> CFG (4)02:24:22: TE ION Restart timer started, proc_idx:0 delay:30000002:24:22: SM: ---TE ION Process Restart 0x78EF9050: reg invoke succeeded (2)02:24:22: SM: CFG (4) --> CFG (4)02:24:22: SM: ---TE ION Process Restart 0x78EF9050: process cfg replay done (5)02:24:22: SM: CFG (4) --> SYNC (5)02:24:22: TE ION Restart timer started, proc_idx:0 delay:900000The output shows typical process restart information that your technical support representative might request if you report a problem after an IP process restart. The information displayed can vary, depending on the conditions that caused the restart.
Related Commands
Command Descriptionshow mpls traffic-eng process-restart iprouting
Displays the status of IP routing and MPLS traffic engineering synchronization after an IP routing process restarts.
show ip route vrf
To display the IP routing table associated with a Virtual Private Network (VPN) routing and forwarding (VRF) instance, use the show ip route vrf command in user EXEC or privileged EXEC mode.
show ip route vrf vrf-name [connected] [protocol [as-number] [tag] [output-modifiers]] [ip-prefix] [list number [output-modifiers]] [profile] [static [output-modifiers]] [summary [output-modifiers]] [supernets-only [output-modifiers]]
Syntax Description
Command Modes
User EXEC
Privileged EXECCommand History
Usage Guidelines
This command displays specified information from the IP routing table of a VRF.
Examples
This example shows the IP routing table associated with the VRF named vrf1:
Router# show ip route vrf vrf1Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGPD - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter areaN1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGPi - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate defaultU - per-user static route, o - ODRT - traffic engineered routeGateway of last resort is not setB 10.0.0.0/8 [200/0] via 10.13.13.13, 00:24:19C 10.0.0.0/8 is directly connected, Ethernet1/3B 10.0.0.0/8 [20/0] via 10.0.0.1, 02:10:22B 10.0.0.0/8 [200/0] via 10.13.13.13, 00:24:20This example shows BGP entries in the IP routing table associated with the VRF named vrf1:
Router# show ip route vrf vrf1 bgpB 10.0.0.0/8 [200/0] via 10.13.13.13, 03:44:14B 10.0.0.0/8 [20/0] via 10.0.0.1, 03:44:12B 10.0.0.0/8 [200/0] via 10.13.13.13, 03:43:14This example shows the IP routing table associated with a VRF named PATH and network 10.22.22.0:
Router# show ip route vrf PATH 10.22.22.0
Routing entry for 10.22.22.0/24Known via "bgp 1", distance 200, metric 0Tag 22, type internalLast update from 10.22.5.10 00:01:07 agoRouting Descriptor Blocks:* 10.22.7.8 (Default-IP-Routing-Table), from 10.11.3.4, 00:01:07 agoRoute metric is 0, traffic share count is 1AS Hops 110.22.1.9 (Default-IP-Routing-Table), from 10.11.1.2, 00:01:07 agoRoute metric is 0, traffic share count is 1AS Hops 110.22.6.10 (Default-IP-Routing-Table), from 10.11.6.7, 00:01:07 agoRoute metric is 0, traffic share count is 1AS Hops 110.22.4.10 (Default-IP-Routing-Table), from 10.11.4.5, 00:01:07 agoRoute metric is 0, traffic share count is 1AS Hops 110.22.5.10 (Default-IP-Routing-Table), from 10.11.5.6, 00:01:07 agoRoute metric is 0, traffic share count is 1AS Hops 1Table 1 describes the significant fields shown when the show ip route vrf vrf-name ip-prefix command is used.
Example of Output Using the Cisco IOS Software Modularity for Layer 3 VPNs Feature
The following is sample output from the show ip route vrf command on routers using the Cisco IOS Software Modularity for Layer 3 VPNs feature. The output includes remote label information and corresponding MPLS flags for prefixes that have remote labels stored in the RIB, if BGP is the label distribution protocol:
Router# show ip route vrf v2 10.2.2.2
Routing entry for 10.2.2.2/32Known via "bgp 1", distance 200, metric 0, type internalRedistributing via ospf 2Advertised by ospf 2 subnetsLast update from 10.0.0.4 00:22:59 agoRouting Descriptor Blocks:* 10.0.0.4 (Default-IP-Routing-Table), from 10.0.0.31, 00:22:59 agoRoute metric is 0, traffic share count is 1AS Hops 0MPLS label: 1300MPLS Flags: MPLS RequiredTable 2 describes the significant fields shown in the display.
Related Commands
Command Descriptionshow ip cache
Displays the Cisco Express forwarding table associated with a VRF.
show ip vrf
Displays the set of defined VRFs and associated interfaces.
show mpls forwarding-table
To display the contents of the Multiprotocol Label Switching (MPLS) Label Forwarding Information Base (LFIB), use the show mpls forwarding-table command in privileged EXEC mode.
show mpls forwarding-table [network {mask | length} | labels label [- label] | interface interface | next-hop address | lsp-tunnel [tunnel-id]] [vrf vrf-name] [detail]
Syntax Description
Command Modes
Privileged EXEC
Command History
Examples
The following is sample output from the show mpls forwarding-table command:
Router# show mpls forwarding-tableLocal Outgoing Prefix Bytes label Outgoing Next HopLabel Label or VC or Tunnel Id switched interface26 No Label 10.253.0.0/16 0 Et4/0/0 10.27.32.428 1/33 10.15.0.0/16 0 AT0/0.1 point2point29 Pop Label 10.91.0.0/16 0 Hs5/0 point2point1/36 10.91.0.0/16 0 AT0/0.1 point2point30 32 10.250.0.97/32 0 Et4/0/2 10.92.0.732 10.250.0.97/32 0 Hs5/0 point2point34 26 10.77.0.0/24 0 Et4/0/2 10.92.0.726 10.77.0.0/24 0 Hs5/0 point2point35 No Label[T] 10.100.100.101/32 0 Tu301 point2point36 Pop Label 10.1.0.0/16 0 Hs5/0 point2point1/37 10.1.0.0/16 0 AT0/0.1 point2point[T] Forwarding through a TSP tunnel.View additional labeling info with the 'detail' optionThe following is sample output from the show mpls forwarding-table command when the IPv6 Provider Edge Router over MPLS feature is configured to allow IPv6 traffic to be transported across an IPv4 MPLS backbone. The labels are aggregated because there are several prefixes for one local label, and the prefix column contains "IPv6" instead of a target prefix.
Router# show mpls forwarding-tableLocal Outgoing Prefix Bytes label Outgoing Next HopLabel Label or VC or Tunnel Id switched interface16 Aggregate IPv6 017 Aggregate IPv6 018 Aggregate IPv6 019 Pop Label 192.168.99.64/30 0 Se0/0 point2point20 Pop Label 192.168.99.70/32 0 Se0/0 point2point21 Pop Label 192.168.99.200/32 0 Se0/0 point2point22 Aggregate IPv6 542423 Aggregate IPv6 357624 Aggregate IPv6 2600The following is sample output from the show mpls forwarding-table command when you specify the detail keyword. If the MPLS EXP level is used as a selection criterion for packet forwarding, a bundle adjacency exp (vcd) field is included in the display. This field includes the EXP value and the corresponding virtual circuit descriptor (VCD) in parentheses. The line in the output that reads "No output feature configured" indicates that the MPLS egress NetFlow accounting feature is not enabled on the outgoing interface for this prefix.
Router# show mpls forwarding-table detailLocal Outgoing Prefix Bytes label Outgoing Next Hoplabel label or VC or Tunnel Id switched interface16 Pop label 10.0.0.6/32 0 AT1/0.1 point2pointBundle adjacency exp(vcd)0(1) 1(1) 2(1) 3(1) 4(1) 5(1) 6(1) 7(1)MAC/Encaps=12/12, MTU=4474, label Stack{}00010000AAAA030000008847No output feature configured17 18 10.0.0.9/32 0 AT1/0.1 point2pointBundle adjacency exp(vcd)0(1) 1(1) 2(1) 3(1) 4(1) 5(1) 6(1) 7(1)MAC/Encaps=12/16, MTU=4470, label Stack{18}00010000AAAA030000008847 00012000No output feature configured18 19 10.0.0.10/32 0 AT1/0.1 point2pointBundle adjacency exp(vcd)0(1) 1(1) 2(1) 3(1) 4(1) 5(1) 6(1) 7(1)MAC/Encaps=12/16, MTU=4470, label Stack{19}00010000AAAA030000008847 00013000No output feature configured19 17 10.0.0.0/8 0 AT1/0.1 point2pointBundle adjacency exp(vcd)0(1) 1(1) 2(1) 3(1) 4(1) 5(1) 6(1) 7(1)MAC/Encaps=12/16, MTU=4470, label Stack{17}00010000AAAA030000008847 00011000No output feature configured20 20 10.0.0.0/8 0 AT1/0.1 point2pointBundle adjacency exp(vcd)0(1) 1(1) 2(1) 3(1) 4(1) 5(1) 6(1) 7(1)MAC/Encaps=12/16, MTU=4470, label Stack{20}00010000AAAA030000008847 00014000No output feature configured21 Pop label 10.0.0.0/24 0 AT1/0.1 point2pointBundle adjacency exp(vcd)0(1) 1(1) 2(1) 3(1) 4(1) 5(1) 6(1) 7(1)MAC/Encaps=12/12, MTU=4474, label Stack{}00010000AAAA030000008847No output feature configured22 Pop label 10.0.0.4/32 0 Et2/3 10.0.0.4MAC/Encaps=14/14, MTU=1504, label Stack{}000427AD10430005DDFE043B8847No output feature configuredThe following is sample output from the show mpls forwarding-table command when you use the detail keyword. In this example, the MPLS egress NetFlow accounting feature is enabled on the first three prefixes, as indicated by the line in the output that reads "Feature Quick flag set."
Router# show mpls forwarding-table detailLocal Outgoing Prefix Bytes label Outgoing Next Hoplabel label or VC or Tunnel Id switched interface16 Aggregate 10.0.0.0/8[V] 0MAC/Encaps=0/0, MTU=0, label Stack{}VPN route: vpn1Feature Quick flag setPer-packet load-sharing, slots: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1517 No label 10.0.0.0/8[V] 0 Et0/0/2 10.0.0.1MAC/Encaps=0/0, MTU=1500, label Stack{}VPN route: vpn1Feature Quick flag setPer-packet load-sharing, slots: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1518 No label 10.42.42.42/32[V] 4185 Et0/0/2 10.0.0.1MAC/Encaps=0/0, MTU=1500, label Stack{}VPN route: vpn1Feature Quick flag setPer-packet load-sharing, slots: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1519 2/33 10.41.41.41/32 0 AT1/0/0.1 point2pointMAC/Encaps=4/8, MTU=4470, label Stack{2/33(vcd=2)}00028847 00002000No output feature configuredCisco 10000 Series Examples
The following is sample output from the show mpls forwarding-table command:
Router# show mpls forwarding-tableLocal Outgoing Prefix Bytes Label Outgoing Next HopLabel Label or VC or Tunnel Id Switched interface16 Pop Label 10.0.0.0/8 0 Fa1/0/0 10.0.0.2Pop Label 10.0.0.0/8 0 Fa1/1/0 10.0.0.217 Aggregate 10.0.0.0/8[V] 570 vpn221 Pop Label 10.11.11.11/32 0 Fa1/0/0 10.0.0.222 Pop Label 10.12.12.12/32 0 Fa1/1/0 10.0.0.223 No Label 10.3.0.0/16[V] 0 Fa4/1/0 10.0.0.2The following is Cisco 10000 series sample output from the show mpls forwarding-table command when you specify the detail keyword:
Router# show mpls forwarding-table detailLocal Outgoing Prefix Bytes Label Outgoing Next HopLabel Label or VC or Tunnel Id Switched interface16 Pop Label 10.0.0.0/8 0 Fa1/0/0 10.0.0.2MAC/Encaps=14/14, MRU=1500, Label Stack{}000B45C93889000B45C930218847No output feature configuredPop Label 10.0.0.0/8 0 Fa1/1/0 10.0.0.2MAC/Encaps=14/14, MRU=1500, Label Stack{}000B45C92881000B45C930288847No output feature configured17 Aggregate 10.0.0.0/8[V] 570 vpn2MAC/Encaps=0/0, MRU=0, Label Stack{}VPN route: vpn2No output feature configured21 Pop Label 10.11.11.11/32 0 Fa1/0/0 10.0.0.2MAC/Encaps=14/14, MRU=1500, Label Stack{}000B45C93889000B45C930218847No output feature configuredTable 3 describes the significant fields shown in the displays.
Explicit-Null Label Example
The following example shows output, including the explicit-null label = 0 (commented in bold), from the show mpls forwarding-table command on a CSC-PE router:
Router# show mpls forwarding-tableLocal Outgoing Prefix Bytes label Outgoing Next Hoplabel label or VC or Tunnel Id switched interface17 Pop label 10.10.0.0/32 0 Et2/0 10.10.0.118 Pop label 10.10.10.0/24 0 Et2/0 10.10.0.119 Aggregate 10.10.20.0/24[V] 020 Pop label 10.10.200.1/32[V] 0 Et2/1 10.10.10.121 Aggregate 10.10.1.1/32[V] 022 0 192.168.101.101/32[V] \0 Et2/1 192.168.101.10123 0 192.168.101.100/32[V] \0 Et2/1 192.168.101.10025 0 192.168.102.125/32[V] 0 Et2/1 192.168.102.125 !outlabel value 0
Table 4 describes the significant fields shown in the display.
Cisco IOS Software Modularity: MPLS Layer 3 VPNs Example
The following is sample output from the show mpls forwarding-table command.
Router# show mpls forwarding-tableLocal Outgoing Prefix Bytes Label Outgoing Next HopLabel Label or Tunnel Id Switched interface16 Pop Label IPv4 VRF[V] 62951000 aggregate/v117 [H] No Label 10.1.1.0/24 0 AT1/0/0.1 point2pointNo Label 10.1.1.0/24 0 PO3/1/0 point2point[T] No Label 10.1.1.0/24 0 Tu1 point2point18 [HT] Pop Label 10.0.0.3/32 0 Tu1 point2point19 [H] No Label 10.0.0.0/8 0 AT1/0/0.1 point2pointNo Label 10.0.0.0/8 0 PO3/1/0 point2point20 [H] No Label 10.0.0.0/8 0 AT1/0/0.1 point2pointNo Label 10.0.0.0/8 0 PO3/1/0 point2point21 [H] No Label 10.0.0.1/32 812 AT1/0/0.1 point2pointNo Label 10.0.0.1/32 0 PO3/1/0 point2point22 [H] No Label 10.1.14.0/24 0 AT1/0/0.1 point2pointNo Label 10.1.14.0/24 0 PO3/1/0 point2point23 [HT] 16 172.1.1.0/24[V] 0 Tu1 point2point24 [HT] 24 10.0.0.1/32[V] 0 Tu1 point2point25 [H] No Label 10.0.0.0/8[V] 0 AT1/1/0.1 point2point26 [HT] 16 10.0.0.3/32[V] 0 Tu1 point2point27 No Label 10.0.0.1/32[V] 0 AT1/1/0.1 point2point[T] Forwarding through a TSP tunnel.View additional labelling info with the 'detail' option[H] Local label is being held down temporarily.Table 5 describes the field relating to the Cisco IOS Software Modularity: MPLS Layer 3 VPNs feature that is shown in the display.
Related Commands
show mpls traffic-eng link-management advertisements
To display local link information that Multiprotocol Label Switching (MPLS) traffic engineering link management is currently flooding into the global traffic engineering topology, use the show mpls traffic-eng link-management advertisements command in user EXEC or privileged EXEC mode.
show mpls traffic-eng link-management advertisements
Syntax Description
This command has no arguments or keywords.
Command Modes
User EXEC
Privileged EXECCommand History
Examples
The following is sample output from the show mpls traffic-eng link-management advertisements command:
Router# show mpls traffic-eng link-management advertisementsFlooding Status: readyConfigured Areas: 1IGP Area[1] ID:: isis level-1System Information::Flooding Protocol: ISISHeader Information::IGP System ID: 0001.0000.0001.00MPLS TE Router ID: 10.106.0.6Flooded Links: 1Link ID:: 0Link IP Address: 10.1.0.6IGP Neighbor: ID 0001.0000.0001.02Admin. Weight: 10Physical Bandwidth: 10000 kbits/secMax Reservable BW: 5000 kbits/secDownstream::Reservable Bandwidth[0]: 5000 kbits/secReservable Bandwidth[1]: 2000 kbits/secReservable Bandwidth[2]: 2000 kbits/secReservable Bandwidth[3]: 2000 kbits/secReservable Bandwidth[4]: 2000 kbits/secReservable Bandwidth[5]: 2000 kbits/secReservable Bandwidth[6]: 2000 kbits/secReservable Bandwidth[7]: 2000 kbits/secAttribute Flags: 0x00000000Table 6 describes the significant fields shown in the display.
The following is sample output from the show mpls traffic-eng link-management advertisements command with the enhanced output, which shows the "IGP recovering" status, from the Cisco IOS Software Modularity: MPLS Layer 3 VPNs feature:
Router# show mpls traffic-eng link-management advertisementsshow mpls traffic-eng link-management advertisementsFlooding Status: ready (IGP recovering)Configured Areas: 1IGP Area[1] ID:: ospf area nilSystem Information::Flooding Protocol: OSPFHeader Information::Table 7 describes the significant fields shown in the display.
Related Commands
show mpls traffic-eng link-management summary
To display a summary of link management information, use the show mpls traffic-eng link-management summary command in user EXEC or privileged EXEC mode.
show mpls traffic-eng link-management summary [interface-name]
Syntax Description
Command Modes
User EXEC
Privileged EXECCommand History
Examples
The following is sample output from the show mpls traffic-eng link-management summary command:
Router# show mpls traffic-eng link-management summarySystem Information::Links Count: 2Flooding System: enabledIGP Area ID:: isis level-1Flooding Protocol: ISISFlooding Status: data floodedPeriodic Flooding: enabled (every 180 seconds)Flooded Links: 1IGP System ID: 0001.0000.0001.00MPLS TE Router ID: 10.106.0.6IGP Neighbors: 1Link ID:: Et4/0/1 (10.1.0.6)Link Status:Physical Bandwidth: 10000 kbits/secMax Reservable BW: 5000 kbits/sec (reserved:0% in, 60% out)MPLS TE Link State: MPLS TE on, RSVP on, admin-up, floodedInbound Admission: reject-hugeOutbound Admission: allow-if-roomAdmin. Weight: 10 (IGP)IGP Neighbor Count: 1Link ID:: AT0/0.2 (10.42.0.6)Link Status:Physical Bandwidth: 155520 kbits/secMax Reservable BW: 5000 kbits/sec (reserved:0% in, 0% out)MPLS TE Link State: MPLS TE on, RSVP onInbound Admission: allow-allOutbound Admission: allow-if-roomAdmin. Weight: 10 (IGP)IGP Neighbor Count: 0Table 8 describes the significant fields shown in the display.
The following is sample output from the show mpls traffic-eng link-management summary command with the enhanced output, which shows the "IGP recovering" status, from the Cisco IOS Software Modularity: MPLS Layer 3 VPNs feature:
Router# show mpls traffic-eng link-management summarySystem Information::Links Count: 3Flooding System: enabled (IGP recovering)IGP Area ID:: ospf area nilFlooding Protocol: OSPFFlooding Status: data floodedPeriodic Flooding: enabled (every 180 seconds)Flooded Links: 0Table 7 describes the significant fields shown in the display.
Related Commands
show mpls traffic-eng process-restart iprouting
To display the status of IP routing and Multiprotocol Label Switching (MPLS) traffic engineering synchronization after an IP routing process restart, use the show mpls traffic-eng process-restart iprouting command in user EXEC or privileged EXEC mode.
show mpls traffic-eng process-restart iprouting
Syntax Description
This command has no arguments or keywords.
Command Modes
User EXEC
Privileged EXECCommand History
Usage Guidelines
This command displays information about the synchronization between the IP routing process and MPLS TE that you can provide to your technical support representative when you are reporting a problem.
All counters are set to zero when the system process initializes and are not reset no matter how often the IP routing process restarts.
The following is sample output from the show mpls traffic-eng process-restart iprouting command when an IP routing process has restarted normally:
Router# show mpls traffic-eng process-restart iproutingIP Routing Restart Statistics:Current State: NORMFlushing State: IDLEState Entered Count Timestamp Timestamp TimestampINIT 1 05/10/06-13:07:01NORM 3 05/10/06-13:07:10 05/10/06-13:10:45 05/10/06-13:11:5NORM-SPCT 0AWAIT-CFG 2 05/10/06-13:10:32 05/10/06-13:11:45CFG 2 05/10/06-13:10:32 05/10/06-13:11:45CMPL-FLSH 0NCMPL-FLSH 2 05/10/06-13:10:32 05/10/06-13:11:45NCMPL-FLSHD 2 05/10/06-13:10:32 05/10/06-13:11:45Stuck State Count Timestamp Timestamp TimestampNo Stuck states encounteredCounter Count Timestamp Timestamp TimestampReg Succeed 40 05/10/06-13:11:51 05/10/06-13:11:45 05/10/06-13:11:45Reg Fail 0Incarnation 5 05/10/06-13:11:45 05/10/06-13:11:45 05/10/06-13:10:37Flushing 2 05/10/06-13:10:32 05/10/06-13:11:45Table 10 describes the normal output of the significant fields shown in the display. You should contact your technical support representative if your display has values other than those described in the table.
Related Commands
Command Descriptiondebug mpls traffic-eng process-restart
Displays information about process restarts for reporting to your technical support representative.
Feature Information for Cisco IOS Software Modularity: MPLS Layer 3 VPNs
Table 11 lists the release history for this feature.
Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.
Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS and Catalyst OS software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Note Table 11 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature.
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