NSF/SSO - MPLS LDP and LDP Graceful Restart

Table Of Contents

NSF/SSO - MPLS LDP and LDP Graceful Restart

Contents

Prerequisites for NSF/SSO - MPLS LDP and LDP Graceful Restart

Restrictions for NSF/SSO - MPLS LDP and LDP Graceful Restart

Information About NSF/SSO - MPLS LDP and LDP Graceful Restart

How NSF/SSO - MPLS LDP and LDP Graceful Restart Works

What Happens During an LDP Restart and an LDP Session Reset

How a Route Processor Advertises That It Supports NSF/SSO - MPLS LDP and LDP Graceful Restart

What Happens if a Route Processor Does Not Have LDP Graceful Restart

Checkpointing

Troubleshooting Tips

How to Configure and Use NSF/SSO - MPLS LDP and LDP Graceful Restart

Configuring MPLS LDP Graceful Restart

Prerequisites

Verifying the Configuration

Configuration Examples for LDP NSF

Configuring NSF/SSO - MPLS LDP and LDP Graceful Restart: Example

Additional References

Related Documents

Standards

MIBs

RFCs

Technical Assistance

Command Reference

debug mpls ldp graceful-restart

mpls label protocol (global configuration)

mpls ldp graceful-restart

mpls ldp graceful-restart timers forwarding-holding

mpls ldp graceful-restart timers max-recovery

mpls ldp graceful-restart timers neighbor-liveness

show mpls ip binding

show mpls ldp bindings

show mpls ldp checkpoint

show mpls ldp graceful-restart

show mpls ldp neighbor

Feature Information for NSF/SSO - MPLS LDP and LDP Graceful Restart

NSF/SSO - MPLS LDP and LDP Graceful Restart

First Published: August 16, 2004

Last Updated: August 21, 2007

Cisco Nonstop Forwarding with Stateful Switchover provides continuous packet forwarding, even during a network processor hardware or software failure. In a redundant system, the secondary processor recovers control plane service during a critical failure in the primary processor. SSO synchronizes the network state information between the primary and the secondary processor.

Multiprotocol Label Switching (MPLS) Label Distribution Protocol (LDP) uses SSO, NSF, and graceful restart to allow a Route Processor to recover from disruption in control plane service (specifically, the LDP component) without losing its MPLS forwarding state. LDP NSF works with LDP sessions between directly connected peers and with peers that are not directly connected (targeted sessions).

Note In this document, the NSF/SSO - MPLS LDP and LDP Graceful Restart feature is called LDP NSF for brevity.

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 NSF/SSO - MPLS LDP and LDP Graceful Restart" 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 NSF/SSO - MPLS LDP and LDP Graceful Restart

•Restrictions for NSF/SSO - MPLS LDP and LDP Graceful Restart

•Information About NSF/SSO - MPLS LDP and LDP Graceful Restart

•How to Configure and Use NSF/SSO - MPLS LDP and LDP Graceful Restart

•Configuration Examples for LDP NSF

•Additional References

•Command Reference

•Feature Information for NSF/SSO - MPLS LDP and LDP Graceful Restart

Prerequisites for NSF/SSO - MPLS LDP and LDP Graceful Restart

For information about supported hardware, see the following documents:

•For Cisco IOS Release 12.2(25)S, see the Cross-Platform Release Notes for Cisco IOS
Release 12.2S.

•For Cisco IOS Release 12.2(28)SB, see the Cross-Platform Release Notes for Cisco IOS
Release 12.2SB.

•For Cisco IOS Release 12.2(33)SRA, see the Release Notes for Cisco IOS Release 12.2SR for the Cisco 7600 Series Routers

•For Cisco IOS Release 12.2(33)SXH, see the following documents:

–Release Notes for Cisco IOS Release 12.2SX on the Catalyst 6500 Series MSFC

–Release Notes for Cisco IOS Release 12.2SX on the Supervisor Engine 720, Supervisor Engine 32, and Supervisor Engine 2

MPLS high availability (HA) requires that neighbor networking devices be NSF-aware.

To perform LDP NSF, Route Processors must be configured for SSO. See the Stateful Switchover feature module for more information:

You must enable nonstop forwarding on the routing protocols running between the provider (P) routers, provider edge (PE) routers, and customer edge (CE) routers. The routing protocols are:

•Border Gateway Protocol (BGP)

•Open Shortest Path First (OSPF)

•Intermediate System-to-Intermediate System (IS-IS)

See the Cisco Nonstop Forwarding feature module for more information.

Restrictions for NSF/SSO - MPLS LDP and LDP Graceful Restart

LDP NSF has the following restrictions:

•Tag Distribution Protocol (TDP) sessions are not supported. Only LDP sessions are supported.

•LDP NSF cannot be configured on label-controlled ATM (LC-ATM) interfaces.

Information About NSF/SSO - MPLS LDP and LDP Graceful Restart

To configure LDP NSF, you need to understand the following concepts:

•How NSF/SSO - MPLS LDP and LDP Graceful Restart Works

•How a Route Processor Advertises That It Supports NSF/SSO - MPLS LDP and LDP Graceful Restart

•Checkpointing

How NSF/SSO - MPLS LDP and LDP Graceful Restart Works

LDP NSF allows a Route Processor to recover from disruption in service without losing its MPLS forwarding state. LDP NSF works under the following circumstances:

•LDP restart—An LDP Restart occurs after an SSO event interrupts LDP communication with all LDP neighbors. If the Route Processors are configured with LDP NSF, the backup Route Processor retains the MPLS forwarding state and reestablishes communication with the LDP neighbors. Then the Route Processor ensures that the MPLS forwarding state is recovered.

•LDP session reset—An LDP session reset occurs after an individual LDP session has been interrupted, but the interruption is not due to an SSO event. The LDP session might have been interrupted due to a TCP or UDP communication problem. If the Route Processor is configured with MPLS LDP NSF support and graceful restart, the Route Processor associates a new session with the previously interrupted session. The LDP bindings and MPLS forwarding states are recovered when the new session is established.

If an SSO event occurs on an LSR, that LSR performs an LDP restart. The adjacent LSRs perform an LDP session reset.

See the following section for more information about LDP restart and reset.

What Happens During an LDP Restart and an LDP Session Reset

In the topology shown in Figure 1, the following elements have been configured:

•LDP sessions are established between Router 1 and Router 2, as well as between Router 2 and Router 3.

•A label switched path (LSP) has been established between Router 1 and Router 3.

•The routers have been configured with LDP NSF.

Figure 1 Example of a Network Using LDP Graceful Restart

The following process shows how LDP recovers when one of the routers fails:

1. When a Route Processor fails on Router 2, communications between the routers is interrupted.

2. Router 1 and Router 3 mark all the label bindings from Router 2 as stale, but they continue to use the bindings for MPLS forwarding.

3. Router 1 and Router 3 attempt to reestablish an LDP session with Router 2.

4. Router 2 restarts and marks all of its forwarding entries as stale. If you issue a show mpls ldp graceful-restart command, the command output includes the following line:
LDP is restarting gracefully. 
5. Router 1 and Router 3 reestablish LDP sessions with Router 2, but they keep their stale label bindings. If you issue a show mpls ldp neighbor command with the graceful-restart keyword, the command output displays the recovering LDP sessions.

6. All three routers readvertise their label binding information. If a label has been relearned after the session has been established, the stale flags are removed. The show mpls forwarding-table command displays the information in the MPLS forwarding table, including the local label, outgoing label or VC, prefix, label-switched bytes, outgoing interface, and next hop.

You can set various timers to limit how long the routers wait for an LDP session to be reestablished before restarting the router. See the following commands for more information:

•mpls ldp graceful-restart timers forwarding-holding

•mpls ldp graceful-restart timers max-recovery

•mpls ldp graceful-restart timers neighbor-liveness

How a Route Processor Advertises That It Supports NSF/SSO - MPLS LDP and LDP Graceful Restart

A Route Processor that is configured to perform LDP NSF includes the Fault Tolerant (FT) Type Length Value (TLV) in the LDP initialization message. The Route Processor sends the LDP initialization message to a neighbor to establish an LDP session.

The FT session TLV includes the following information:

•The Learn from Network (L) flag is set to 1, which indicates that the Route Processor is configured to perform LDP Graceful Restart.

•The Reconnect Timeout field shows the time (in milliseconds) that the neighbor should wait for a reconnection if the LDP session is lost. This field is set to 120 seconds and cannot be configured.

•The Recovery Time field shows the time (in milliseconds) that the neighbor should retain the MPLS forwarding state during a recovery. If a neighbor did not preserve the MPLS forwarding state before the restart of the control plane, the neighbor sets the recovery time to 0.

What Happens if a Route Processor Does Not Have LDP Graceful Restart

If a Route Processor is not configured for MPLS LDP Graceful Restart and it attempts to establish an LDP session with a Route Processor that is configured with LDP Graceful Restart, the following events occur:

1. The Route Processor that is configured with MPLS LDP Graceful Restart sends an initialization message that includes the FT session TLV value to the Route Processor that is not configured with MPLS LDP Graceful Restart.

2. The Route Processor that is not configured for MPLS LDP Graceful Restart receives the LDP initialization message and discards the FT session TLV.

3. The two Route Processors create a normal LDP session but do not have the ability to perform MPLS LDP Graceful Restart.

You must enable all Route Processors with MPLS LDP Graceful Restart for an LDP session to be preserved during an interruption in service.

Checkpointing

Checkpointing is a function that copies state information from the active Route Processor to the backup Route Processor, thereby ensuring that the backup Route Processor has the latest information. If the active Route Processor fails, the backup Route Processor can take over.

For the LDP NSF feature, the checkpointing function copies the active Route Processor's LDP local label bindings to the backup Route Processor. The active Route Processor sends updates to the backup Route Processor when local label bindings are modified as a result of routing changes.

Note Local label bindings that are allocated by BGP and null local label bindings are not included in the checkpointing operation.

The checkpointing function is enabled by default.

To display checkpointing data, issue the show mpls ldp graceful-restart command on the active Route Processor.

To check that the active and backup Route Processors have identical copies of the local label bindings, you can issue the show mpls ldp bindings command with the detail keyword on the active and backup Route Processors. This command displays the local label bindings that have been saved. The active Route Processor and the backup Route Processor should have the same local label bindings.

Troubleshooting Tips

You can use the debug mpls ldp graceful-restart command to enable the display of MPLS LDP checkpoint events and errors.

How to Configure and Use NSF/SSO - MPLS LDP and LDP Graceful Restart

•Configuring MPLS LDP Graceful Restart (required)

•Verifying the Configuration (optional)

Configuring MPLS LDP Graceful Restart

MPLS LDP Graceful Restart (GR) is enabled globally. When you enable LDP GR, it has no effect on existing LDP sessions. LDP GR is enabled for new sessions that are established after the feature has been globally enabled.

Prerequisites

•Route Processors must be configured for SSO. See the Stateful Switchover feature module for more information:

•You must enable Nonstop Forwarding on the routing protocols running between the P, PE, routers, and CE routers. See the Cisco Nonstop Forwarding feature module for more information.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip cef [distributed]

4. mpls ldp graceful-restart

5. interface type slot/port

6. mpls ip

7. mpls label protocol {ldp | tdp | both}

DETAILED STEPS
Command or Action

Purpose

Step 1

enable
Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2

configure terminal
Example:

Router# configure terminal

Enters global configuration mode.

Step 3

ip cef [distributed]
Example:

Router(config)# ip cef distributed

Enables distributed Cisco Express Forwarding on
Cisco 7500 series routers. Distributes Cisco Express Forwarding information to line cards.

Note For the Cisco 10000 series routers, IP Cisco Express Forwarding is on by default and it cannot be disabled.
Step 4
mpls ldp graceful-restart
Example:
Router (config)# mpls ldp graceful-restart
Enables the router to protect the LDP bindings and MPLS forwarding state during a disruption in service.
Step 5
interface type slot/port
Example:
Router(config)# interface pos 3/0 
Specifies an interface and enters interface configuration mode.
Step 6

mpls ip
Example:

Router(config-if)# mpls ip

Configures MPLS hop-by-hop forwarding for an interface.

Step 7

mpls label protocol {ldp | tdp | both}
Example:

Router(config-if)# mpls label protocol ldp

Configures the use of LDP for an interface. You must use LDP. You can also issue the mpls label protocol ldp command in global configuration mode, which enables LDP on all interfaces configured for MPLS.
Verifying the Configuration

Use the following procedure to verify that MPLS LDP Graceful Restart has been configured correctly.

SUMMARY STEPS

1. show mpls ldp graceful-restart

2. show mpls ldp neighbor graceful restart

3. show mpls ldp checkpoint

DETAILED STEPS

Step 1 show mpls ldp graceful-restart

The command output displays Graceful Restart sessions and session parameters:
Router# show mpls ldp graceful-restart
LDP Graceful Restart is enabled
Neighbor Liveness Timer: 5 seconds
Max Recovery Time: 200 seconds
Down Neighbor Database (0 records):
Graceful Restart-enabled Sessions:
VRF default:
    Peer LDP Ident: 10.18.18.18:0, State: estab
    Peer LDP Ident: 10.17.17.17:0, State: estab
Step 2 show mpls ldp neighbor graceful restart

The command output displays the Graceful Restart information for LDP sessions:
Router# show mpls ldp neighbor graceful-restart
Peer LDP Ident: 10.20.20.20:0; Local LDP Ident 10.17.17.17:0
  TCP connection: 10.20.20.20.16510 - 10.17.17.17.646
  State: Oper; Msgs sent/rcvd: 8/18; Downstream
  Up time: 00:04:39
  Graceful Restart enabled; Peer reconnect time (msecs): 120000
Peer LDP Ident: 10.19.19.19:0; Local LDP Ident 10.17.17.17:0
  TCP connection: 10.19.19.19.11007 - 10.17.17.17.646
  State: Oper; Msgs sent/rcvd: 8/38; Downstream
  Up time: 00:04:30
  Graceful Restart enabled; Peer reconnect time (msecs): 120000
Step 3 show mpls ldp checkpoint

The command output displays the summary of the checkpoint information:
Router# show mpls ldp checkpoint
Checkpoint status: dynamic-sync
Checkpoint resend timer: not running
5 local bindings in add-skipped
9 local bindings in added
1 of 15+ local bindings in none
Configuration Examples for LDP NSF

This section contains the following examples:

•Configuring NSF/SSO - MPLS LDP and LDP Graceful Restart: Example

Configuring NSF/SSO - MPLS LDP and LDP Graceful Restart: Example

The following configuration example shows the LDP NSF feature configured on three routers. (See Figure 2.) In this configuration example, Router 1 creates an LDP session with Router 2. Router 1 also creates a targeted session with Router 3 through a TE tunnel using Router 2.

Figure 2 MPLS LDP: NSF/SSO Support and Graceful Restart Configuration Example

Router 1—Cisco 7500 Series
boot system slot0:rsp-pv-mz 
hw-module slot 2 image slot0:rsp-pv-mz 
hw-module slot 3 image slot0:rsp-pv-mz  
redundancy 
mode sso 
ip subnet-zero
ip cef
mpls label range 16 10000 static 10001 1048575
mpls label protocol ldp
mpls ldp logging neighbor-changes
mpls ldp graceful-restart
mpls traffic-eng tunnels
no mpls traffic-eng auto-bw timers frequency 0
mpls ldp router-id Loopback0 force
!
interface Loopback0
 ip address 172.20.20.20 255.255.255.255
 no ip directed-broadcast
 no ip mroute-cache
!
interface Tunnel1
 ip unnumbered Loopback0
 no ip directed-broadcast
 mpls label protocol ldp
 mpls ip
 tunnel destination 10.19.19.19
 tunnel mode mpls traffic-eng
 tunnel mpls traffic-eng autoroute announce
 tunnel mpls traffic-eng priority 7 7
 tunnel mpls traffic-eng bandwidth  500
 tunnel mpls traffic-eng path-option 1 dynamic
!
interface ATM5/1/0
 no ip address
 no ip directed-broadcast
 atm clock INTERNAL
 no atm enable-ilmi-trap
 no atm ilmi-keepalive
!
interface ATM5/1/0.5 point-to-point
 ip address 172.17.0.2 255.255.0.0
 no ip directed-broadcast
 no atm enable-ilmi-trap
 pvc 6/100 
  encapsulation aal5snap
mpls label protocol ldp
mpls traffic-eng tunnels
mpls ip
ip rsvp bandwidth 1000
!
router ospf 100
 log-adjacency-changes
 redistribute connected
     nsf enforce global
     network 172.17.0.0 0.255.255.255 area 100
 network 172.20.20.20 0.0.0.0 area 100
 mpls traffic-eng router-id Loopback0
 mpls traffic-eng area 100
Router 2—Cisco 7500 Series
boot system slot0:rsp-pv-mz 
hw-module slot 2 image slot0:rsp-pv-mz 
hw-module slot 3 image slot0:rsp-pv-mz  
redundancy 
mode sso 
!
ip cef
no ip domain-lookup
mpls label range 17 10000 static 10001 1048575
mpls label protocol ldp
mpls ldp logging neighbor-changes
mpls ldp graceful-restart
mpls traffic-eng tunnels
no mpls traffic-eng auto-bw timers frequency 0
no mpls advertise-labels
mpls ldp router-id Loopback0 force
!
interface Loopback0
 ip address 172.18.17.17 255.255.255.255
 no ip directed-broadcast
!
interface ATM4/0/0
 no ip address
 no ip directed-broadcast
 no ip mroute-cache
 atm clock INTERNAL
 atm sonet stm-1
 no atm enable-ilmi-trap
 no atm ilmi-keepalive
!
interface ATM4/0/0.5 point-to-point
 ip address 172.17.0.1 255.255.0.0
 no ip directed-broadcast
 no atm enable-ilmi-trap
 pvc 6/100 
  encapsulation aal5snap
mpls label protocol ldp
mpls traffic-eng tunnels
mpls ip
ip rsvp bandwidth 1000
!
interface POS5/1/0
 ip address 10.0.0.1 255.0.0.0
 no ip directed-broadcast
 encapsulation ppp
 mpls label protocol ldp
 mpls traffic-eng tunnels
 mpls ip
 no peer neighbor-route
 clock source internal
 ip rsvp bandwidth 1000
!
router ospf 100
 log-adjacency-changes
     nsf enforce global
 redistribute connected
 network 10.0.0.0 0.255.255.255 area 100
 network 172.17.0.0 0.255.255.255 area 100
 network 172.18.17.17 0.0.0.0 area 100
 mpls traffic-eng router-id Loopback0
 mpls traffic-eng area 100
!
ip classless
Router 3—Cisco 7500 Series
boot system slot0:rsp-pv-mz 
hw-module slot 2 image slot0:rsp-pv-mz 
hw-module slot 3 image slot0:rsp-pv-mz  
redundancy 
mode sso 
!
ip subnet-zero
ip cef
!
no ip finger
no ip domain-lookup
mpls label protocol ldp
mpls ldp neighbor 10.11.11.11 targeted ldp
mpls ldp logging neighbor-changes
mpls ldp graceful-restart
mpls traffic-eng tunnels
no mpls traffic-eng auto-bw timers frequency 0
mpls ldp discovery directed-hello interval 12
mpls ldp discovery directed-hello holdtime 130
mpls ldp discovery directed-hello accept
mpls ldp router-id Loopback0 force
!
interface Loopback0
 ip address 172.19.19.19 255.255.255.255
 no ip directed-broadcast
!
interface POS1/0
 ip address 10.0.0.2 255.0.0.0
 no ip directed-broadcast
 encapsulation ppp
 mpls label protocol ldp
 mpls traffic-eng tunnels
 mpls ip
 no peer neighbor-route
 clock source internal
 ip rsvp bandwidth 1000
!
router ospf 100
 log-adjacency-changes
     nsf enforce global
 redistribute connected
 network 10.0.0.0 0.255.255.255 area 100
 network 172.19.19.19 0.0.0.0 area 100
 mpls traffic-eng router-id Loopback0
 mpls traffic-eng area 100
!
ip classless
Router 1—Cisco 10000 Series
boot system flash:c10k2-p11-mz 
redundancy 
mode sso 
ip subnet-zero
ip cef
mpls label protocol ldp
mpls ldp logging neighbor-changes
mpls ldp graceful-restart
no mpls traffic-eng auto-bw timers frequency 0
mpls ldp router-id Loopback0 force
!
interface Loopback0
 ip address 172.20.20.20 255.255.255.255
 no ip directed-broadcast
 no ip mroute-cache
!
interface ATM5/1/0
 no ip address
 no ip directed-broadcast
 atm clock INTERNAL
 no atm enable-ilmi-trap
 no atm ilmi-keepalive
!
interface ATM5/1/0.5 point-to-point
 ip address 172.18.0.2 255.255.0.0
 no ip directed-broadcast
 no atm enable-ilmi-trap
 pvc 6/100 
  encapsulation aal5snap
mpls label protocol ldp
mpls ip
!
router ospf 100
 log-adjacency-changes
 redistribute connected
     nsf enforce global
     network 172.18.0.0 0.255.255.255 area 100
 network 172.20.20.20 0.0.0.0 area 100
Router 2—Cisco 10000 Series
boot system flash:c10k2-p11-mz 
redundancy 
mode sso 
!
ip cef
no ip domain-lookup
mpls label protocol ldp
mpls ldp logging neighbor-changes
mpls ldp graceful-restart
no mpls traffic-eng auto-bw timers frequency 0
mpls ldp router-id Loopback0 force
!
interface Loopback0
 ip address 172.17.17.17 255.255.255.255
 no ip directed-broadcast
!
interface ATM4/0/0
 no ip address
 no ip directed-broadcast
 no ip mroute-cache
 atm clock INTERNAL
 atm sonet stm-1
 no atm enable-ilmi-trap
 no atm ilmi-keepalive
!
interface ATM4/0/0.5 point-to-point
 ip address 172.18.0.1 255.255.0.0
 no ip directed-broadcast
 no atm enable-ilmi-trap
 pvc 6/100 
  encapsulation aal5snap
mpls label protocol ldp
mpls ip
!
interface POS5/1/0
 ip address 10.0.0.1 255.0.0.0
 no ip directed-broadcast
 encapsulation ppp
 mpls label protocol ldp
 mpls ip
 no peer neighbor-route
 clock source internal
!
router ospf 100
 log-adjacency-changes
     nsf enforce global
 redistribute connected
 network 10.0.0.0 0.255.255.255 area 100
 network 172.18.0.0 0.255.255.255 area 100
 network 172.17.17.17 0.0.0.0 area 100
 mpls traffic-eng router-id Loopback0
!
ip classless
Router 3—Cisco 10000 Series
boot system flash:c10k2-p11-mz 
redundancy 
mode sso 
!
ip subnet-zero
ip cef
!
no ip finger
no ip domain-lookup
mpls label protocol ldp
mpls ldp logging neighbor-changes
mpls ldp graceful-restart
no mpls traffic-eng auto-bw timers frequency 0
mpls ldp router-id Loopback0 force
!
interface Loopback0
 ip address 172.19.19.19 255.255.255.255
 no ip directed-broadcast
!
interface POS1/0
 ip address 10.0.0.2 255.0.0.0
 no ip directed-broadcast
 encapsulation ppp
 mpls label protocol ldp
 mpls ip
 no peer neighbor-route
 clock source internal
!
router ospf 100
 log-adjacency-changes
     nsf enforce global
 redistribute connected
 network 10.0.0.0 0.255.255.255 area 100
 network 172.19.19.19 0.0.0.0 area 100
 mpls traffic-eng router-id Loopback0
!
ip classless
Additional References

The following sections provide references related to the NSF/SSO - MPLS LDP and LDP Graceful Restart feature.

Related Documents

Related Topic

Document Title

Stateful switchover

Stateful Switchover

MPLS Label Distribution Protocol

MPLS Label Distribution Protocol (LDP)

Cisco nonstop forwarding

Cisco Nonstop Forwarding

Standards

Standard

Title

None

—

MIBs

MIB

MIBs Link

MPLS Label Distribution Protocol MIB Version 8 Upgrade

To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:

http://www.cisco.com/go/mibs

RFCs

RFC

Title

RFC 3036

LDP Specification

RFC 3478

Graceful Restart Mechanism for Label Distribution

Technical Assistance

Description

Link

The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies. Access to most tools on the Cisco Support website requires a Cisco.com user ID and password. If you have a valid service contract but do not have a user ID or password, you can register on Cisco.com.

http://www.cisco.com/techsupport

Command Reference

This section documents only commands that are new or modified.

•debug mpls ldp graceful-restart

•mpls label protocol (global configuration)

•mpls ldp graceful-restart

•mpls ldp graceful-restart timers forwarding-holding

•mpls ldp graceful-restart timers max-recovery

•mpls ldp graceful-restart timers neighbor-liveness

•show mpls ip binding

•show mpls ldp bindings

•show mpls ldp checkpoint

•show mpls ldp graceful-restart

•show mpls ldp neighbor

debug mpls ldp graceful-restart

To display debugging information for Multiprotocol (MPLS) Label Distribution Protocol (LDP) Stateful Switchover (SSO) Nonstop Forwarding (NSF) Support and Graceful Restart, use the debug mpls ldp graceful-restart command in privileged EXEC mode. To disable the display of this debugging information, use the no form of this command.

debug mpls ldp graceful-restart
no debug mpls ldp graceful-restart
Syntax Description

This command has no arguments or keywords.

Defaults

The display of debugging information is not enabled.

Command Modes

Privileged EXEC

Command History

Release

Modification

12.0(29)S

This command was introduced.

12.3(14)T

This command was integrated into Cisco IOS Release 12.3(14)T.

12.2(25)S

This command was integrated into Cisco IOS Release 12.2(25)S.

12.2(28)SB

This command was integrated into Cisco IOS Release 12.2(28)SB and implemented on the Cisco 10000 series routers.

12.2(33)SRA

This command was integrated into Cisco IOS Release 12.2(33)SRA.

12.2(33)SXH

This command was integrated into Cisco IOS Release 12.2(33)SXH.

Usage Guidelines

This command shows events and errors related to LDP Graceful Restart.

Examples

The following example shows sample output from the debug mpls ldp graceful-restart command. The output shows that a session was lost. The status message show the events that happen during recovery of the bindings.
Router# debug mpls ldp graceful-restart
LDP GR: GR session 10.110.0.10:0:: lost
LDP GR: down nbr 10.110.0.10:0:: created [1 total]
LDP GR: GR session 10.110.0.10:0:: bindings retained
LDP GR: down nbr 10.110.0.10:0:: added all 7 addresses [7 total]
LDP GR: down nbr 10.110.0.10:0:: state change (None -> Reconnect-Wait)
LDP GR: down nbr 10.110.0.10:0:: reconnect timer started [120000 msecs]
LDP GR: down nbr 10.110.0.10:0:: added to bindings task queue [1 entries]
LDP GR: searching for down nbr record (10.110.0.10:0, 10.2.0.10)
LDP GR: search for down nbr record (10.110.0.10:0, 10.2.0.10) returned 10.110.0.10:0
LDP GR: Added FT Sess TLV (Rconn 120000, Rcov 120000) to INIT msg to 10.110.0.10:0
LDP GR: Tagcon querying for up to 12 bindings update tasks
LDP GR: down nbr 10.110.0.10:0:: requesting bindings MARK for {10.110.0.10:0, 1}
LDP GR: down nbr 10.110.0.10:0:: removed from bindings task queue [0 entries]
LDP GR: Requesting 1 bindings update tasks [0 left in queue]
LDP GR: 2.0.0.0/8:: updating binding from 10.110.0.10:0, inst 1:: marking stale; 
LDP GR: 10.2.0.0/16:: updating binding from 10.110.0.10:0, inst 1:: marking stale; 
LDP GR: 14.0.0.14/32:: updating binding from 10.110.0.10:0, inst 1:: marking stale; 
LDP GR: searching for down nbr record (10.110.0.10:0, 10.2.0.10)
LDP GR: search for down nbr record (10.110.0.10:0, 10.2.0.10) returned 10.110.0.10:0
LDP GR: Added FT Sess TLV (Rconn 120000, Rcov 120000) to INIT msg to 10.110.0.10:0
LDP GR: searching for down nbr record (10.110.0.10:0, 10.2.0.10)
LDP GR: search for down nbr record (10.110.0.10:0, 10.2.0.10) returned 10.110.0.10:0
LDP GR: Added FT Sess TLV (Rconn 120000, Rcov 120000) to INIT msg to 10.110.0.10:0
LDP GR: searching for down nbr record (10.110.0.10:0, 10.2.0.10)
LDP GR: search for down nbr record (10.110.0.10:0, 10.2.0.10) returned 10.110.0.10:0
LDP GR: Added FT Sess TLV (Rconn 120000, Rcov 120000) to INIT msg to 10.110.0.10:0
LDP GR: searching for down nbr record (10.110.0.10:0, 10.2.0.10)
LDP GR: search for down nbr record (10.110.0.10:0, 10.2.0.10) returned 10.110.0.10:0
LDP GR: Added FT Sess TLV (Rconn 120000, Rcov 120000) to INIT msg to 10.110.0.10:0
LDP GR: searching for down nbr record (10.110.0.10:0, 10.2.0.10)
LDP GR: search for down nbr record (10.110.0.10:0, 10.2.0.10) returned 10.110.0.10:0
LDP GR: Added FT Sess TLV (Rconn 120000, Rcov 120000) to INIT msg to 10.110.0.10:0
LDP GR: Received FT Sess TLV from 10.110.0.10:0  (fl 0x1, rs 0x0, rconn 120000, rcov 
120000)
LDP GR: GR session 10.110.0.10:0:: allocated instance, 2
LDP GR: GR session 10.110.0.10:0:: established
LDP GR: GR session 10.110.0.10:0:: found down nbr 10.110.0.10:0
LDP GR: down nbr 10.110.0.10:0:: reconnect timer stopped
LDP GR: down nbr 10.110.0.10:0:: state change (Reconnect-Wait -> Recovering)
LDP GR: down nbr 10.110.0.10:0:: recovery timer started [120000 msecs]
%LDP-5-GR: GR session 10.110.0.10:0 (inst. 2): starting graceful recovery
%LDP-5-NBRCHG: LDP Neighbor 10.110.0.10:0 is UP
LDP GR: 2.0.0.0//8:: refreshing stale binding from 10.110.0.10:0, inst 1 -> inst 2
LDP GR: 10.43.0.0//16:: refreshing stale binding from 10.110.0.10:0, inst 1 -> inst 2
LDP GR: down nbr 10.110.0.10:0:: recovery timer expired
%LDP-5-GR: GR session 10.110.0.10:0 (inst. 2): completed graceful recovery
LDP GR: down nbr 10.110.0.10:0:: destroying record [0 left]
LDP GR: down nbr 10.110.0.10:0:: state change (Recovering -> Delete-Wait)
LDP GR: down nbr 10.110.0.10:0:: added to bindings task queue [1 entries]
LDP GR: Tagcon querying for up to 12 bindings update tasks
LDP GR: down nbr 10.110.0.10:0:: requesting bindings DEL for {10.110.0.10:0, 1}
LDP GR: down nbr 10.110.0.10:0:: removed from bindings task queue [0 entries]
LDP GR: Requesting 1 bindings update tasks [0 left in queue]
LDP GR: GR session 10.110.0.10:0:: released instance, 1
The debug output is formatted in three general ways.

•LDP GR: GR session 10.110.0.10:0:: found down nbr 10.110.0.10:0

•down nbr 10.110.0.10:0:: removed from bindings task queue [0 entries]

•LDP GR: 2.0.0.0/8:: updating binding from 10.110.0.10:0, inst 1:: marking stale;

Table 1 describes the fields for the debug command output.

Table 1 debug mpls ldp graceful-restart Command Field Descriptions

Field

Description

LDP GR

Identifies LDP Graceful Restart application

GR session 10.110.0.10:0

ID of the LDP session that is enabled for Graceful Restart.

found down nbr 10.110.0.10:0

Describes the event that is happening to that LDP session.

down nbr 10.110.0.10:0::

Identifies the Down Neighbor record, which logs the state of a recently lost Graceful Restart session.

removed from bindings task queue [0 entries]

Describes the event that is happening to the recently lost Graceful Restart session.

2.0.0.0/8::

Identifies the Forwarding Equivalence Class (FEC) associated with the remote label binding being modified. The FEC identifies the Label Information Base (LIB) entry.

updating binding

Lists the operation being performed on the remote label binding.

10.110.0.10:0, inst 1:: marking stale;

Identifies the LDP session during which the remote label binding was learned.

:

Related Commands

Command

Description

show mpls ldp graceful-restart

Displays a summary of the LDP Graceful Restart status.

mpls label protocol (global configuration)

To specify the Label Distribution Protocol (LDP) for a platform, use the mpls label protocol command in global configuration mode. To restore the default LDP, use the no form of this command.

mpls label protocol {ldp | tdp}
no mpls label protocol
Syntax Description

ldp

Specifies that LDP is the default label distribution protocol.

tdp

Specifies that Tag Distribution Protocol (TDP) is the default label distribution protocol.

Defaults

LDP is the default label distribution protocol.

Command Modes

Global configuration

Command History

Release

Modification

12.0(10)ST

This command was introduced.

12.0(14)ST

This command was integrated into Cisco IOS Release 12.0(14)ST.

12.1(2)T

This command was integrated into Cisco IOS Release 12.1(2)T.

12.1(8a)E

This command was integrated into Cisco IOS Release 12.1(8a)E.

12.2(2)T

This command was integrated into Cisco IOS Release 12.2(2)T.

12.2(4)T

This command was integrated into Cisco IOS Release 12.2(4)T.

12.2(8)T

This command was integrated into Cisco IOS Release 12.2(8)T.

12.0(21)ST

This command was integrated into Cisco IOS Release 12.0(21)ST.

12.0(22)S

This command was integrated into Cisco IOS Release 12.0(22)S.

12.0(23)S

This command was integrated into Cisco IOS Release 12.0(23)S.

12.2(14)S

This command was integrated into Cisco IOS Release 12.2(14)S.

12.2(13)T

This command was integrated into Cisco IOS Release 12.2(13)T.

12.4(3)

The command default changed from TDP to LDP.

12.2(28)SB

This command was integrated into Cisco IOS Release 12.2(28)SB and implemented on the Cisco 10000 series routers.

12.2(33)SRA

This command was integrated into Cisco IOS Release 12.2(33)SRA.

12.2(33)SXH

This command was integrated into Cisco IOS Release 12.2(33)SXH.

Usage Guidelines

If neither the global mpls label protocol ldp command nor the interface mpls label protocol ldp command is used, all label distribution sessions use LDP.

Note Use caution when upgrading the image on a router that uses TDP. Ensure that the TDP sessions are established when the new image is loaded. You can accomplish this by issuing the global configuration command mpls label protocol tdp. Issue this command and save it to the startup configuration before loading the new image. Alternatively, you can enter the command and save the running configuration immediately after loading the new image.

Examples

The following command establishes LDP as the label distribution protocol for the platform:
Router(config)# mpls label protocol ldp
Related Commands

Command

Description

mpls idp maxhops

Limits the number of hops permitted in an LSP established by the Downstream on Demand method of label distribution.

show mpls interfaces

Displays information about one or more or all interfaces that are configured for label switching.

mpls ldp graceful-restart

To enable Multiprotocol Label Switching (MPLS) Label Distribution Protocol (LDP) Graceful Restart, use the mpls ldp graceful-restart command in global configuration mode. To disable LDP Graceful Restart, use the no form of this command.

mpls ldp graceful-restart
no mpls ldp graceful-restart
Syntax Description

This command has no arguments or keywords.

Defaults

LDP Graceful Restart is not enabled.

Command Modes

Global configuration

Command History

Release

Modification

12.0(29)S

This command was introduced.

12.3(14)T

This command was integrated into Cisco IOS Release 12.3(14)T.

12.2(25)S

This command was integrated into Cisco IOS Release 12.2(25)S.

12.2(28)SB

This command was integrated into Cisco IOS Release 12.2(28)SB and implemented on the Cisco 10000 series routers.

12.2(33)SRA

This command was integrated into Cisco IOS Release 12.2(33)SRA.

12.2(33)SXH

This command was integrated into Cisco IOS Release 12.2(33)SXH.

Usage Guidelines

LDP Graceful Restart must be enabled before an LDP session is established.

Using the no form of the command disables the Graceful Restart functionality on all LDP sessions.

Examples

The command in the following example enables LDP Graceful Restart on a router:
Router(config)# mpls ldp graceful-restart
Related Commands

Command

Description

mpls ldp graceful-restart timers forwarding-holding

Specifies the amount of time the MPLS forwarding state should be preserved after the control plane restarts.

mpls ldp graceful-restart timers max-recovery

Specifies the amount of time a router should hold stale label-FEC bindings after an LDP session has been reestablished.

mpls ldp graceful-restart timers neighbor-liveness

Specifies the amount of time a router should wait for an LDP session to be reestablished.

mpls ldp graceful-restart timers forwarding-holding

To specify the amount of time the Multiprotocol Label Switching (MPLS) forwarding state should be preserved after the control plane restarts, use the mpls ldp graceful-restart timers forwarding-holding command in global configuration mode. To revert to the default timer value, use the no form of this command.

mpls ldp graceful-restart timers forwarding-holding secs
no mpls ldp graceful-restart timers forwarding-holding
Syntax Description

secs

The amount of time (in seconds) that the MPLS forwarding state should be preserved after the control plane restarts. The default is 300 seconds. The acceptable range of values is 30 to 300 seconds.

Defaults

After the control plane on the Cisco 7500 and Cisco 10000 series router restarts, the MPLS forwarding state is preserved for 300 seconds.

Command Modes

Global configuration

Command History

Release

Modification

12.2(25)S

This command was introduced.

12.2(28)SB

This command was integrated into Cisco IOS Release 12.2(28)SB and implemented on the Cisco 10000 series routers.

12.2(33)SRA

This command was integrated into Cisco IOS Release 12.2(33)SRA.

12.2(33)SXH

This command was integrated into Cisco IOS Release 12.2(33)SXH.

Usage Guidelines

Configuring the local forwarding-holding timer to a value less than the IOS FT Reconnect Timeout of 120 seconds may prevent an LDP session from being established. Configure the forwarding-holding timer to less than 120 seconds only if an LDP neighbor has an FT Reconnect Timeout value of less than 120 seconds.

If the timer expires, all entries that are marked stale are deleted.

Examples

In the following example, the MPLS forwarding state is preserved for 300 seconds after the control plane restarts:
Router(config)# mpls ldp graceful-restart timers forwarding-holding 300
Related Commands

Command

Description

mpls ldp graceful-restart timers max-recovery

Specifies the amount of time a router should hold stale label-FEC bindings after an LDP session has been reestablished.

mpls ldp graceful-restart timers neighbor-liveness

Specifies the amount of time a router should wait for an LDP session to be reestablished.

mpls ldp graceful-restart timers max-recovery

To specify the amount of time a router should hold stale label-Forwarding Equivalence Class (FEC) bindings after a Label Distribution Protocol (LDP) session has been reestablished, use the mpls ldp graceful-restart timers max-recovery command in global configuration mode. To revert to the default timer value, use the no form of this command.

mpls ldp graceful-restart timers max-recovery secs
no mpls ldp graceful-restart timers max-recovery
Syntax Description

secs

The amount of time (in seconds) that the router should hold stale label-FEC bindings after an LDP session has been reestablished. The default is 120 seconds. The acceptable range of values is 15 to 600 seconds.

Defaults

Stale label-FEC bindings are held for 120 seconds after an LDP session has been reestablished.

Command Modes

Global configuration

Command History

Release

Modification

12.0(29)S

This command was introduced.

12.3(14)T

This command was integrated into Cisco IOS Release 12.3(14)T.

12.2(28)SB

This command was integrated into Cisco IOS Release 12.2(28)SB and implemented on the Cisco 10000 series routers.

12.2(33)SRA

This command was integrated into Cisco IOS Release 12.2(33)SRA.

12.2(33)SXH

This command was integrated into Cisco IOS Release 12.2(33)SXH.

Usage Guidelines

After the timer expires, all stale label-FEC bindings learned from the associated LDP session are removed, which results in the removal of any forwarding table entries that are based on those bindings.

Examples

In the following example, the router should hold stale label-FEC bindings after an LDP session has been reestablished for 180 seconds:
Router(config)# mpls ldp graceful-restart timers max-recovery 180
Related Commands

Command

Description

mpls ldp graceful-restart timers forwarding-holding

Specifies the amount of time the MPLS forwarding state should be preserved after the control plane restarts.

mpls ldp graceful-restart timers neighbor-liveness

Specifies the amount of time a router should wait for an LDP session to be reestablished.

mpls ldp graceful-restart timers neighbor-liveness

To specify the upper bound on the amount of time a router should wait for a Label Distribution Protocol (LDP) session to be reestablished, use the mpls ldp graceful-restart timers neighbor-liveness command in global configuration mode. To revert to the default timer value, use the no form of this command.

mpls ldp graceful-restart timers neighbor-liveness secs
no mpls ldp graceful-restart timers neighbor-liveness
Syntax Description

secs

The amount of time (in seconds) that the router should wait for an LDP session to be reestablished. The default is 120 seconds. The range is 5 to 300 seconds.

Defaults

The default is a maximum of 120 seconds.

Command Modes

Global configuration

Command History

Release

Modification

12.0(29)S

This command was introduced.

12.3(14)T

This command was integrated into Cisco IOS Release 12.3(14)T.

12.2(28)SB

This command was integrated into Cisco IOS Release 12.2(28)SB and implemented on the Cisco 10000 series routers.

12.2(33)SRA

This command was integrated into Cisco IOS Release 12.2(33)SRA.

12.2(33)SXH

This command was integrated into Cisco IOS Release 12.2(33)SXH.

Usage Guidelines

The amount of time a router waits for an LDP session to be reestablished is the lesser of the following values:

•The value of the peer's fault tolerant (FT) type length value (TLV) reconnect timeout

•The value of the neighbor liveness timer

If the router cannot reestablish an LDP session with the neighbor in the time allotted, the router deletes the stale label-FEC bindings received from that neighbor.

Examples

The command in the following example sets the amount of time that the router should wait for an LDP session to be reestablished to 30 seconds:
Router(config)# mpls ldp graceful-restart timers neighbor-liveness 30
Related Commands

Command

Description

mpls ldp graceful-restart timers forwarding-holding

Specifies the amount of time the MPLS forwarding state should be preserved after the control plane restarts.

mpls ldp graceful-restart timers max-recovery

Specifies the amount of time a router should hold stale label-FEC bindings after an LDP session has been reestablished.

show mpls ip binding

To display specified information about label bindings learned by the Multiprotocol Label Switching (MPLS) Label Distribution Protocol (LDP), use the show mpls ip binding command in user EXEC or privileged EXEC mode.

show mpls ip binding [vrf vrf-name | all] [network {mask | length} [longer-prefixes]]
[neighbor address | local] [local-label {atm vpi vci | label [- label]}]
[remote-label {atm vpi vci | label [- label]}] [interface interface] [generic | atm]
show mpls ip binding [vrf vrf-name | all] [detail | summary]
Cisco 10000 Series Routers

show mpls ip binding [network {mask | length} [longer-prefixes]] [neighbor address | local] [local-label label [- label]] [remote-label label [- label]] [generic]
show mpls ip binding [detail | summary]
Syntax Description

vrf vrf-name

(Optional) Displays the LDP neighbors for the specified Virtual Private Network (VPN) routing and forwarding (VRF) instance (vrf-name).

Note This keyword and argument pair does not apply to the Cisco 10000 series routers.

all

(Optional) Displays binding information for all VRFs.

Note This keyword does not apply to the Cisco 10000 series routers.

network

(Optional) Defines the destination network number.

mask

Defines the network mask, written as A.B.C.D.

length

Defines the mask length (1 to 32 characters).

longer-prefixes

(Optional) Selects any prefix that matches the mask with a length from 1 to 32 characters.

neighbor address

(Optional) Displays label bindings assigned by the selected neighbor.

local

(Optional) Displays the local label bindings.

local-label atm vpi vci

(Optional) Displays the entry with the locally assigned ATM label that matches the specified ATM label value. The virtual path identifier (VPI) range is 0 to 4095. The virtual channel identifier (VCI) range is 0 to 65535.

Note These keywords and arguments do not apply to the Cisco 10000 series routers.

local-label label - label

(Optional) Displays entries with locally assigned labels that match the specified label values. Use the label - label arguments and keyword to indicate the label range. The hyphen (-) keyword is required for a label range.

remote-label atm vpi vci

(Optional) Displays entries with remotely assigned ATM label values learned from neighbor routers that match the specified ATM label value. The VPI range is 0 to 4095. The VCI range is 0 to 65535.

Note These keywords and arguments do not apply to the Cisco 10000 series routers.

remote-label label - label

(Optional) Displays entries with remotely assigned labels learned from neighbor routers that match the specified label values. Use the label - label arguments and keyword to indicate the label range. The hyphen (-) keyword is required for a label range.

interface interface

(Optional) Displays label bindings associated with the specified interface (for label-controlled (LC)-ATM only).

Note This keyword and argument pair does not apply to the Cisco 10000 series routers.

generic

(Optional) Displays only generic (non-LC-ATM) label bindings.

atm

(Optional) Displays only LC-ATM label bindings.

Note This keyword does not apply to the Cisco 10000 series routers.

detail

(Optional) Displays detailed information about label bindings learned by LDP.

summary

(Optional) Displays summary information about label bindings learned by LDP.

Defaults

All label bindings are displayed when no optional arguments or keywords are specified.

Command Modes

User EXEC
Privileged EXEC

Command History

Release

Modification

12.0(10)ST

This command was introduced.

12.0(14)ST

This command was modified to reflect MPLS VPN support for LDP.

12.1(2)T

This command was integrated into Cisco IOS Release 12.1(2)T.

12.1(8a)E

This command was integrated into Cisco IOS Release 12.1(8a)E.

12.2(2)T

This command was integrated into Cisco IOS Release 12.2(2)T.

12.2(4)T

The VPI range of values was extended to 4095.

12.2(8)T

This command was integrated into Cisco IOS Release 12.2(8)T.

12.0(21)ST

This command was integrated into Cisco IOS Release 12.0(21)ST.

12.0(22)S

This command was integrated into Cisco IOS Release 12.0(22)S.

12.0(23)S

This command was integrated into Cisco IOS Release 12.0(23)S.

12.2(13)T

This command was integrated into Cisco IOS Release 12.2(13)T.

12.2(14)S

This command was integrated into Cisco IOS Release 12.2(14)S.

12.2(25)S

The detail keyword was added to display checkpoint status for local label bindings.

12.2(28)SB

This command was integrated into Cisco IOS Release 12.2(28)SB and implemented on the Cisco 10000 series routers.

12.2(33)SRA

This command was integrated into Cisco IOS Release 12.2(33)SRA.

12.2(33)SXH

This command was integrated into Cisco IOS Release 12.2(33)SXH.

Usage Guidelines

The show mpls ip binding command displays label bindings learned by LDP or the Tag Distribution Protocol (TDP).

Note TDP is not supported for LDP features in Cisco IOS 12.0(30)S and later releases, 12.2(27)SBC and later 12.2S releases, and 12.3(14)T and later releases.

To summarize information about label bindings learned by LDP, use the show mpls ip binding summary command in user EXEC or privileged EXEC mode.

A request can specify that the entire database be displayed, that a summary of entries from the database be displayed, or that the display be limited to a subset of entries. The subset can be limited according to any of the following:

•Prefix

•Input or output label values or ranges

•Neighbor advertising the label

•Interface for label bindings of interest (LC-ATM only)

Note LC-ATM label binding interface does not apply to the Cisco 10000 series routers.

•Generic (non-LC-ATM) label bindings

•LC-ATM label bindings

Note LC-ATM label binding interface does not apply to the Cisco 10000 series routers.

Examples

The following is sample output from the show mpls ip binding command. The output shows all the label bindings in the database.
Router# show mpls ip binding 
  10.0.0.0/8 
        in label:     20        
        out label:    26        lsr: 10.0.0.55:0    
        out vc label: 1/80      lsr: 10.0.7.7:2      ATM1/0.8
                      Active    ingress 3 hops (vcd 49) 
  172.16.0.0/8 
        in label:     25        
        in vc label:  1/36      lsr: 10.0.7.7:2      ATM1/0.8
                      Active    egress (vcd 55) 
        out label:    imp-null  lsr: 10.0.0.55:0     inuse
  192.168.0.66/32 
        in label:     26        
        in vc label:  1/39      lsr: 10.0.7.7:2      ATM1/0.8
                      Active    egress (vcd 58) 
        out label:    16        lsr: 10.0.0.55:0     inuse
.
.
.
In the following example, a request is made for the display of the label binding information for prefix 192.168.44.0/24:
Router# show mpls ip binding 192.168.44.0 24
  192.168.44.0/24 
        in label:     24        
        in vc label:  1/37      lsr: 10.0.7.7:2      ATM1/0.8
                      Active    egress (vcd 56) 
        out label:    imp-null  lsr: 10.0.0.55:0     inuse
In the following example, the local-label keyword is used to request that label binding information be displayed for the prefix with local label 58:
Router# show mpls ip binding local-label 58
  192.168.0.0/16 
        in label:     58        
        out label:    imp-null  lsr: 10.0.0.55:0     inuse
The following sample output shows the label bindings for the VPN routing and forwarding instance named vpn1:
Router# show mpls ip binding vrf vpn1
  10.3.0.0/16 
        in label:    117       
        out label:   imp-null  lsr:10.14.14.14:0   
  10.13.13.13/32 
        in label:    1372      
        out label:   268       lsr:10.14.14.14:0   
  10.14.14.14/32 
        in label:    118       
        out label:   imp-null  lsr:10.14.14.14:0   
  10.15.15.15/32 
        in label:    1370      
        out label:   266       lsr:10.14.14.14:0   
  10.16.16.16/32 
        in label:    8370      
        out label:   319       lsr:10.14.14.14:0   
  10.18.18.18/32 
        in label:    21817     
        out label:   571       lsr:10.14.14.14:0   
  30.2.0.0/16 
        in label:    6943      
        out label:   267       lsr:10.14.14.14:0   
  10.30.3.0/16 
        in label:    2383      
        out label:   imp-null  lsr:10.14.14.14:0   
  10.30.4.0/16 
        in label:    77        
        out label:   imp-null  lsr:10.14.14.14:0   
  10.30.5.0/16 
        in label:    20715     
        out label:   504       lsr:10.14.14.14:0   
  10.30.7.0/16 
        in label:    17        
        out label:   imp-null  lsr:10.14.14.14:0   
  10.30.10.0/16 
        in label:    5016      
        out label:   269       lsr:10.14.14.14:0   
  10.30.13.0/16 
        in label:    76        
        out label:   imp-null  lsr:10.14.14.14:0 
The following sample output shows label binding information for all VRFs:
Router# show mpls ip binding all     
  10.0.0.0/24 
        in label:     imp-null  
        out label:    imp-null  lsr: 10.131.0.1:0     
  10.11.0.0/24 
        in label:     imp-null  
        out label:    imp-null  lsr: 10.131.0.1:0 
  10.101.0.1/32 
        out label:    imp-null  lsr: 10.131.0.1:0 
  10.131.0.1/32 
        in label:     20        
        out label:    imp-null  lsr: 10.131.0.1:0      inuse
  10.134.0.1/32 
        in label:     imp-null  
        out label:    16        lsr: 10.131.0.1:0     
VRF vrf1:
  10.0.0.0/24 
        out label:    imp-null  lsr: 10.132.0.1:0     
  10.11.0.0/24 
        out label:    imp-null  lsr: 10.132.0.1:0     
  10.12.0.0/24 
        in label:     17        
        out label:    imp-null  lsr: 10.132.0.1:0     
  10.132.0.1/32 
        out label:    imp-null  lsr: 10.132.0.1:0     
  10.134.0.2/32 
        in label:     18        
        out label:    16        lsr: 10.132.0.1:0     
  10.134.0.4/32 
        in label:     19        
        out label:    17        lsr: 10.132.0.1:0     
  10.138.0.1/32 
        out label:    imp-null  lsr: 10.132.0.1:0
Cisco 10000 Series Examples Only

The following sample shows binding information for a Cisco 10000 series router:
Router# show mpls ip binding 
  0.0.0.0/0 
        in label:     imp-null  
  10.29.0.0/16 
        in label:     imp-null  
        out label:    imp-null  lsr: 10.66.66.66:0   
        out label:    imp-null  lsr: 10.44.44.44:0   
  10.20.0.0/24 
        in label:     imp-null  
        out label:    26        lsr: 10.66.66.66:0   
        out label:    imp-null  lsr: 10.44.44.44:0   
  10.30.0.0/24 
        in label:     imp-null  
        out label:    imp-null  lsr: 10.66.66.66:0   
        out label:    18        lsr: 10.44.44.44:0   
  10.44.44.44/32 
        in label:     21        
        out label:    19        lsr: 10.66.66.66:0   
        in label:     imp-null  
        out label:    26        lsr: 10.66.66.66:0   
        out label:    imp-null  lsr: 10.44.44.44:0   
  10.30.0.0/24 
        in label:     imp-null  
        out label:    imp-null  lsr: 10.66.66.66:0   
        out label:    18        lsr: 10.44.44.44:0   
  10.44.44.44/32 
        in label:     21        
        out label:    19        lsr: 10.66.66.66:0   
        out label:    imp-null  lsr: 10.44.44.44:0    inuse
  10.55.55.55/32 
        in label:     imp-null  
        out label:    25        lsr: 10.66.66.66:0   
        out label:    55        lsr: 10.44.44.44:0   
  10.66.66.66/32 
        in label:     18        
        out label:    imp-null  lsr: 10.66.66.66:0    inuse
        out label:    16        lsr: 10.44.44.44:0   
  10.255.254.244/32 
        in label:     24        
        out label:    16        lsr: 10.66.66.66:0   
        out label:    59        lsr: 10.44.44.44:0   
In the following example on a Cisco 10000 series router, a request is made for the display of the label binding information for prefix 172.16.44.44/32:
Router# show mpls ip binding 172.16.44.44 32
  172.16.44.44/32 
        in label:     21        
        out label:    19        lsr: 10.66.66.66:0   
        out label:    imp-null  lsr: 10.44.44.44:0    inuse
In the following example on a Cisco 10000 series router, the local-label keyword is used to request that label binding information be displayed for the prefix with local label 21:
Router# show mpls ip binding local-label 21
  10.44.44.44/32 
        in label:     21
Table 2 describes the significant fields shown in the displays.

Table 2 show mpls ip binding Field Descriptions

Field

Description

172.16.44.44/32

Destination prefix. Indicates that the following lines are for a particular destination (network/mask).

in label

Incoming label. This is the local label assigned by the label switch router (LSR) and advertised to other LSRs. The label value imp-null indicates the well-known Implicit NULL label.

out label

Outgoing label. This is a remote label learned from an LDP neighbor. The neighbor is identified by its LDP ID in the lsr field.

inuse

Indicates that the outgoing label is in use for Multiprotocol Label Switching (MPLS) forwarding, that is, it is installed in the MPLS forwarding table (the Label Forwarding Information Base [LFIB]).

in vc label

Incoming MPLS ATM label. This is the local VPI/VCI assigned by the LSR as the incoming label for the destination and advertised to the upstream LSRs.

Note This field applies to the Cisco 7500 series routers only.

out vc label

Outgoing MPLS ATM label. This is the VPI/VCI learned from the destination next hop as its label for the destination and advertised to this LSR.

Note This field applies to the Cisco 7500 series routers only.

ATM1/0.8

The ATM interface with which the MPLS ATM label is associated.

Note This field applies to the Cisco 7500 series routers only.

Active

State of the label VC (LVC) associated with the destination prefix.

Note This field applies to the Cisco 7500 series routers only.

States are the following:

•Active. Established and operational.

•Bindwait. Waiting for a response from the destination next hop.

•Remote Resource Wait. Waiting for resources (VPI/VCI) to become available on the destination next hop.

•Parent Wait. Transit LVC upstream side waiting for downstream side to become active.

•AbortAckWait. Waiting for response to a Label Abort message sent to the destination next hop.

•ReleaseWait. Waiting for response to a Label Withdraw message sent to an upstream neighbor.

vcd 49

Virtual circuit descriptor number for the LVC.

Note This field applies to the Cisco 7500 series routers only.

ingress 3 hops

Indicates whether the LSR is an ingress, transit, or egress node for the destination.

Note This field applies to the Cisco 7500 series routers only.

Options include the following:

•Ingress 3 hops. The LSR is an ingress edge router for the MPLS ATM cloud for the destination.

•Egress. The LSR is an egress edge router for the MPLS ATM cloud for the destination.

•Transit. The LSR is a transit LSR within the MPLS ATM cloud for the destination.

The following sample output displays detailed information about the label bindings:
Router# show mpls ip binding detail 
  10.0.0.0/8, rev 2, chkpt: add-skipped
        in label:     imp-null   (owner LDP)
          Advertised to:
          10.60.60.60:0          10.30.30.30:0          
        out label:    imp-null  lsr: 10.60.60.60:0   
        out label:    imp-null  lsr: 10.30.30.30:0   
  10.10.10.10/32, rev 18, chkpt: added
        in label:     17         (owner LDP)
          Advertised to:
          10.60.60.60:0          10.30.30.30:0          
        out label:    142       lsr: 10.60.60.60:0   
        out label:    19        lsr: 10.30.30.30:0    inuse
  10.0.0.1/32, rev 10, chkpt: add-skipped
        in label:     imp-null   (owner LDP)
          Advertised to:
          10.60.60.60:0          10.30.30.30:0          
        out label:    21        lsr: 10.60.60.60:0   
        out label:    17        lsr: 10.30.30.30:0   
  10.30.30.30/32, rev 20, chkpt: added
        in label:     18         (owner LDP)
          Advertised to:
          10.60.60.60:0          10.30.30.30:0          
        out label:    22        lsr: 10.60.60.60:0   
Table 3 describes the significant fields shown in the display.

Table 3 show mpls ip binding detail Field Descriptions

Field

Description

chkpt

The status of the checkpointed entry.

•add-skipped—Means that the local label is a null label and does not need to be checkpointed.

•added— Means that the checkpoints entry was copied to the backup Route Processor (RP)

owner

The application that created the binding.

•owner LDP—Means that LDP created the binding.

•owner other—Means that another application created the binding, possibly Border Gateway protocol (BGP).

Advertised to

The LSRs that received the local label binding.

inuse or stale

The status of the label.

•inuse—Indicates that the outgoing label is in use for MPLS forwarding, that is, it is installed in the MPLS forwarding table (LFIB).

•stale—Indicates a label that is no longer in use. This happens when an LDP session is lost and the routers begin a graceful restart. Then the remote label bindings are marked stale.

Cisco 7500 Series Example Only

The following sample output shows summary information about the label bindings learned by LDP:
Router# show mpls ip binding summary 
Total number of prefixes: 53
Generic label bindings
                      assigned        learned
       prefixes      in labels     out labels
             53             53             51
ATM label bindings summary
      interface   total  active   local  remote   Bwait   Rwait  IFwait
       ATM1/0.8      47      47      40       7       0       0       0
Router#
Table 4 describes the significant fields shown in the display.

Table 4 show mpls ip binding summary Field Descriptions (Cisco 7500 Series Example)

Field

Description

Total number of prefixes

Number of destinations for which the LSR has label bindings.

Generic label bindings

Indicates the start of summary information for "generic" label bindings. Generic labels are used for MPLS forwarding on all interface types except MPLS ATM interfaces.

prefixes

Number of destinations for which the LSR has a generic label binding.

assigned in labels

Number of prefixes for which the LSR has assigned an incoming (local) label.

learned out labels

Number of prefixes for which the LSR has learned an outgoing (remote) label from an LDP neighbor.

ATM label bindings summary

Indicates the start of summary information for MPLS ATM label bindings. An ATM label is a VPI/VCI.

interface

Indicates a row in the ATM label bindings summary table. The summary information in the row is for ATM labels associated with this interface.

total

Total number of ATM labels associated with the interface.

active

Number of ATM labels (LVCs) in the active (operational) state.

local

Number of ATM labels assigned by this LSR for the interfaces. These are incoming labels.

remote

Number of ATM labels learned from the neighbor LSR for this interface. These are outgoing labels.

Bwait

Number of bindings (LVCs) waiting for a label assignment from the neighbor LSR for the interface.

Rwait

Number of bindings (LVCs) waiting for resources (VPI/VCIs) to become available on the neighbor LSR for the interface.

IFwait

Number of bindings (LVCs) waiting for labels to be installed for switching use.

Cisco 10000 Series Example Only

The following sample output displays summary information about the label bindings learned by LDP:
Router# show mpls ip binding summary 
Total number of prefixes: 53
Generic label bindings
                      assigned        learned
       prefixes      in labels     out labels
             53             53             51
Table 5 describes the significant fields shown in the display.

Table 5 show mpls ip binding summary Field Descriptions (Cisco 10000 Series Example)

Field

Description

Total number of prefixes

Number of destinations for which the LSR has label bindings.

Generic label bindings

Indicates the start of summary information for "generic" label bindings. Generic labels are used for MPLS forwarding on all interface types except MPLS ATM interfaces.

prefixes

Number of destinations for which the LSR has a generic label binding.

assigned in labels

Number of prefixes for which the LSR has assigned an incoming (local) label.

learned out labels

Number of prefixes for which the LSR has learned an outgoing (remote) label from an LDP neighbor.

Related Commands

Command

Description

show mpls atm-ldp bindings

Displays specified entries from the ATM label binding database.

show mpls ldp bindings

Displays the contents of the LIB.

show mpls ldp bindings

To display the contents of the Label Information Base (LIB), use the show mpls ldp bindings command in user EXEC or privileged EXEC mode:

show mpls ldp bindings [vrf vrf-name | all] [network {mask | length} [longer-prefixes]]
[local-label label [- label]] [remote-label label [- label]] [neighbor address | local] [detail]
Syntax Description

vrf vrf-name

(Optional) Displays the label bindings for the specified Virtual Private Network (VPN) routing and forwarding (VRF) instance (vrf-name).

all

(Optional) Displays LIB information for all VPNs.

network

(Optional) Defines the destination network number.

mask

Specifies the network mask, written as A.B.C.D.

length

Specifies the mask length (1 to 32 characters).

longer-prefixes

(Optional) Selects any prefix that matches mask with a length from 1 to 32 characters.

local-label label - label

(Optional) Display entries matching local label values. Use the label - label arguments and keyword to indicate the label range. The hyphen (-) keyword is required for a label range.

remote-label label - label

(Optional) Displays entries matching the label values assigned by a neighbor router. Use the label - label arguments and keyword to indicate the label range. The hyphen (-) keyword is required for a label range.

neighbor address

(Optional) Displays the label bindings assigned by the selected neighbor.

local

(Optional) Displays the local label bindings.

detail

(Optional) Displays the checkpoint status of the local label bindings.

Defaults

If no optional keywords or arguments are supplied, the command displays the LIB for the default routing domain only.

Command Modes

User EXEC
Privileged EXEC

Command History

Release

Modification

11.1CT

This command was introduced.

12.0(10)ST

This command was modified to reflect Multiprotocol Label Switching (MPLS) Internet Engineering Task Force (IETF) command syntax and terminology.

12.0(14)ST

This command was modified to reflect MPLS Virtual Private Network (VPN) support for Label Distribution Protocol (LDP).

12.1(2)T

This command was integrated into Cisco IOS Release 12.1(2)T.

12.1(8a)E

This command was integrated into Cisco IOS Release 12.1(8a)E.

12.2(2)T

This command was integrated into Cisco IOS Release 12.2(2)T.

12.2(4)T

This command was integrated into Cisco IOS Release 12.2(4)T.

12.2(8)T

This command was integrated into Cisco IOS Release 12.2(8)T.

12.0(21)ST

This command was integrated into Cisco IOS Release 12.0(21)ST.

12.0(22)S

This command was integrated into Cisco IOS Release 12.0(22)S.

12.0(23)S

This command was integrated into Cisco IOS Release 12.0(23)S.

12.2(13)T

This command was integrated into Cisco IOS Release 12.2(13)T.

12.2(14)S

This command was integrated into Cisco IOS Release 12.2(14)S.

12.2(25)S

The detail keyword was added.

12.2(28)SB

This command was integrated into Cisco IOS Release 12.2(28)SB and implemented on the Cisco 10000 series routers.

12.2(33)SRA

This command was integrated into Cisco IOS Release 12.2(33)SRA.

12.2(33)SXH

This command was integrated into Cisco IOS Release 12.2(33)SXH.

Usage Guidelines

The show mpls ldp bindings command displays label bindings learned by the LDP or Tag Distribution Protocol (TDP).

Note TDP is not supported for LDP features in Cisco IOS 12.0(30)S and later releases, 12.2(28)SB and later 12.2S releases, and 12.3(14)T and later releases.

A request can specify that the entire database be displayed, or that the display be limited to a subset of entries according to the following:

•Prefix

•Input or output label values or ranges

•Neighbor advertising the label

Note The show mpls ip binding command includes the output generated by the show mpls ldp bindings command. On the Cisco 7000 series router, this command displays information about label bindings for LC-ATM interfaces.

Examples

The following is sample output from the show mpls ldp bindings command. This form of the command displays the contents of the LIB for the default routing domain.
Router# show mpls ldp bindings
  10.0.0.0/8, rev 9
        local binding:  label: imp-null
        remote binding: lsr: 10.10.0.55:0, label: 17
        remote binding: lsr: 10.66.0.66:0, label: 18
        remote binding: lsr: 10.0.0.44:0, label: imp-null
  172.16.0.0/8, rev 17
        local binding:  label: 19
        remote binding: lsr: 10.0.0.55:0, label: imp-null
        remote binding: lsr: 10.66.0.66:0, label: 16
        remote binding: lsr: 10.0.0.44:0, label: imp-null
  192.168.0.66/32, rev 19
        local binding:  label: 20
        remote binding: lsr: 10.0.0.55:0, label: 19
        remote binding: lsr: 10.66.0.66:0, label: imp-null
        remote binding: lsr: 10.0.0.44:0, label: 18
.
.
.
The following is sample output from the show mpls ldp bindings network length longer-prefixes neighbor address variant of the command; it displays labels learned from label switch router (LSR) 10.144.0.44 for network 10.166.0.0 and any of its subnets. The use of the neighbor keyword suppresses the output of local labels and labels learned from other neighbors.
Router# show mpls ldp bindings 10.166.0.0 8 longer-prefixes neighbor 10.144.0.44
  10.166.44.0/16, rev 31
        remote binding: lsr: 10.144.0.44:0, label: 25
  10.166.45.0/16, rev 33
        remote binding: lsr: 10.144.0.44:0, label: 26
  10.166.245.0/16, rev 71
        remote binding: lsr: 10.144.0.44:0, label: 45
  10.166.246.0/16, rev 73
        remote binding: lsr: 10.144.0.44:0, label: 46
. 
. 
.
The following is sample output from the show mpls ldp bindings vrf vpn1 command, which displays the label bindings for the specified VPN routing and forwarding instance named vpn1:
Router# show mpls ldp bindings vrf vpn1
  10.3.3.0/16, rev 164
        local binding: label:117
        remote binding:lsr:10.14.14.14:0, label:imp-null
  10.13.13.13/32, rev 1650
        local binding: label:1372
        remote binding:lsr:10.14.14.14:0, label:268
  10.14.14.14/32, rev 165
        local binding: label:118
        remote binding:lsr:10.14.14.14:0, label:imp-null
  10.15.15.15/32, rev 1683
        local binding: label:1370
        remote binding:lsr:10.14.14.14:0, label:266
  10.16.16.16/32, rev 775
        local binding: label:8370
        remote binding:lsr:10.14.14.14:0, label:319
  10.18.18.18/32, rev 1655
        local binding: label:21817
        remote binding:lsr:10.14.14.14:0, label:571
  10.30.2.0/16, rev 1653
        local binding: label:6943
        remote binding:lsr:10.14.14.14:0, label:267
  10.30.3.0/16, rev 413
        local binding: label:2383
        remote binding:lsr:10.14.14.14:0, label:imp-null
  10.30.4.0/16, rev 166
        local binding: label:77
        remote binding:lsr:10.14.14.14:0, label:imp-null
  10.30.5.0/16, rev 1429
        local binding: label:20715
        remote binding:lsr:10.14.14.14:0, label:504
  10.30.7.0/16, rev 4
        local binding: label:17
        remote binding:lsr:10.14.14.14:0, label:imp-null
  10.30.10.0/16, rev 422
        local binding: label:5016
        remote binding:lsr:10.14.14.14:0, label:269
. 
. 
. 
The following is sample output from the show mpls ldp bindings all command, which displays the label bindings for all VRFs:
Router# show mpls ldp bindings all 
  lib entry: 10.0.0.0/24, rev 4
        local binding:  label: imp-null
        remote binding: lsr: 10.131.0.1:0, label: imp-null
  lib entry: 10.11.0.0/24, rev 15
        local binding:  label: imp-null
        remote binding: lsr: 10.131.0.1:0, label: imp-null
  lib entry: 10.101.0.1/32, rev 18
        remote binding: lsr: 10.131.0.1:0, label: imp-null
  lib entry: 10.131.0.1/32, rev 17
        local binding:  label: 20
        remote binding: lsr: 10.131.0.1:0, label: imp-null
  lib entry: 10.134.0.1/32, rev 6
        local binding:  label: imp-null
        remote binding: lsr: 10.131.0.1:0, label: 16
VRF vrf1:
  lib entry: 10.0.0.0/24, rev 6
        remote binding: lsr: 10.132.0.1:0, label: imp-null
  lib entry: 10.11.0.0/24, rev 7
        remote binding: lsr: 10.132.0.1:0, label: imp-null
  lib entry: 10.12.0.0/24, rev 8
        local binding:  label: 17
        remote binding: lsr: 10.132.0.1:0, label: imp-null
  lib entry: 10.132.0.1/32, rev 4
        remote binding: lsr: 10.132.0.1:0, label: imp-null
  lib entry: 10.134.0.2/32, rev 9
        local binding:  label: 18
        remote binding: lsr: 10.132.0.1:0, label: 16
  lib entry: 10.134.0.4/32, rev 10
        local binding:  label: 19
        remote binding: lsr: 10.132.0.1:0, label: 17
  lib entry: 10.138.0.1/32, rev 5
        remote binding: lsr: 10.132.0.1:0, label: imp-null
The following is sample output from the show mpls ldp bindings detail command:
Router# show mpls ldp bindings detail
lib entry: 10.3.3.0/16, rev 2, 
        local binding:  label: imp-null
          Advertised to:
          10.20.20.20:0          10.25.25.25:0          
        remote binding: lsr: 10.20.20.20:0, label: imp-null  stale
        remote binding: lsr: 10.25.25.25:0, label: imp-null  stale
  lib entry: 10.13.1.0/24, rev 4, 
        local binding:  label: imp-null
          Advertised to:
          10.20.20.20:0          10.25.25.25:0          
        remote binding: lsr: 10.20.20.20:0, label: imp-null  stale
        remote binding: lsr: 10.25.25.25:0, label: 16  stale
  lib entry: 10.13.2.0/24, rev 6, 
        local binding:  label: imp-null
          Advertised to:
          10.20.20.20:0          10.25.25.25:0          
        remote binding: lsr: 10.20.20.20:0, label: 16  stale
        remote binding: lsr: 10.25.25.25:0, label: imp-null  stale
  lib entry: 10.6.1.0/24, rev 22, 
        local binding:  label: 21
          Advertised to:
          10.20.20.20:0          10.25.25.25:0          
        remote binding: lsr: 10.20.20.20:0, label: 19  stale
        remote binding: lsr: 10.25.25.25:0, label: imp-null  stale
Table 6 describes the significant fields shown in the display.

Table 6 show mpls ldp bindings Field Descriptions

Field

Description

10.3.3.0/16

IP prefix and mask for a particular destination (network/mask).

rev 9

Revision number that is used internally to manage label distribution for this destination.

Advertised to

The LSRs that received the label binding.

local binding

Labels assigned by the local LSR.

remote binding

List of outgoing labels for this destination learned from other LSRs. Each item in this list identifies the LSR from which the outgoing label was learned and the label itself. The LSR is identified by its LDP identifier.

stale

After an LDP session is lost and the routers begin a graceful restart, the remote label bindings are marked stale.

Related Commands

Command

Description

show mpls ip binding

Displays specified information about label bindings learned by the MPLS LDP.

show mpls ldp neighbor

Displays the status of LDP sessions.

show mpls ldp checkpoint

To display information about the Label Distribution Protocol (LDP) checkpoint system on the active route processor, use the show mpls ldp checkpoint command in user EXEC or privileged EXEC mode.

show mpls ldp checkpoint
Syntax Description

This command has no arguments or keywords.

Command Modes

User EXEC
Privileged EXEC

Command History

Release

Modification

12.2(25)S

This command was introduced.

12.2(28)SB

This command was integrated into Cisco IOS Release 12.2(28)SB and implemented on the Cisco 10000 series routers.

12.2(33)SRA

This command was integrated into Cisco IOS Release 12.2(33)SRA.

12.2(33)SXH

This command was integrated into Cisco IOS Release 12.2(33)SXH.

Usage Guidelines

This command shows the following LDP checkpointing information:

•The status of the checkpointing system

•The status of the resend timer

•The number of Label Information Base (LIB) entries in a checkpointed state

This command displays checkpoint status information only for the active route processor.

Examples

The following example shows the LDP checkpoint settings and configuration:
Router# show mpls ldp checkpoint
Checkpoint status: dynamic-sync
Checkpoint resend timer: not running
5 local bindings in add-skipped
9 local bindings in added
1 of 15+ local bindings in none
Table 7 describes the significant fields shown in the display.

Table 7 show mpls ldp checkpoint Field Descriptions

Field

Description

Checkpoint status

The status of the checkpointing system. If the status shows dynamic-sync or another enabled state, then the checkpointing system is enabled.

If the status shows disabled, then the checkpointing system is disabled.

Checkpoint resend timer

The status of the resend timer.

local bindings in add-skipped

The number of local bindings that were not checkpointed, because they do not need to be checkpointed. For example, local label bindings using null labels are not checkpointed.

local bindings in added

The number of local bindings that were copied to the standby route processor.

local bindings in none

The number of local bindings that reside on the active route processor and need to be copied to the backup route processor.

Related Commands

Command

Description

show mpls ldp graceful-restart

Displays a summary of the LDP Graceful Restart status.

show mpls ldp graceful-restart

To display a summary of the Label Distribution Protocol (LDP) Graceful Restart status, use the show mpls ldp graceful-restart command in user EXEC or privileged EXEC mode.

show mpls ldp graceful-restart
Syntax Description

This command has no arguments or keywords.

Command Modes

User EXEC
Privileged EXEC

Command History

Release

Modification

12.0(29)S

This command was introduced.

12.2(25)S

This command was integrated into Cisco IOS Release 12.2(25)S.

12.3(14)T

This command was integrated into Cisco IOS Release 12.3(14)T.

12.2(28)SB

This command was integrated into Cisco IOS Release 12.2(28)SB and implemented on the Cisco 10000 series routers.

12.2(33)SRA

This command was integrated into Cisco IOS Release 12.2(33)SRA.

12.2(33)SXH

This command was integrated into Cisco IOS Release 12.2(33)SXH.

Usage Guidelines

This command shows the following information about LDP sessions:

•Configured parameters.

•The state of the LDP sessions (for which Graceful Restart was negotiated during initialization).

•The list of LDP sessions for which graceful recovery is pending. However, the router has retained the state information from those neighbors.

Examples

The following example shows a summary of the LDP Graceful Restart settings and configuration:
Router# show mpls ldp graceful-restart
LDP Graceful Restart is enabled
Neighbor Liveness Timer: 5 seconds
Max Recovery Time: 200 seconds
Down Neighbor Database (0 records):
Graceful Restart-enabled Sessions:
VRF default:
    Peer LDP Ident: 10.18.18.18:0, State: estab
    Peer LDP Ident: 10.17.17.17:0, State: estab
Table 8 describes the significant fields shown in the display.

Table 8 show mpls ldp graceful-restart Field Descriptions

Field

Description

Neighbor Liveness Timer

The number of seconds the neighbor liveness timer is set for.

Max Recovery Time

The number of seconds the maximum recovery timer is set for.

Down Neighbor Database

Information about the down (failed or restarting) LDP neighbor.

Graceful Restart-enabled Sessions

Information about the LDP sessions that are enabled for Graceful Restart.

Peer LDP Ident

The LDP ID of the provider edge (PE) neighbor.

State

The state of the session with the neighbor.

Related Commands

Command

Description

show mpls ldp neighbor

Displays the status of LDP sessions.

show mpls ldp neighbor

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

show mpls ldp neighbor [vrf vrf-name | all] [address | interface] [detail] [graceful-restart]
Syntax Description

vrf vrf-name

(Optional) Displays the LDP neighbors for the specified Virtual Private Network (VPN) routing and forwarding (VRF) instance (vrf-name).

all

(Optional) Displays LDP neighbor information for all VPNs, including those in the default routing domain.

address

(Optional) Identifies the neighbor with this IP address.

interface

(Optional) Defines the LDP neighbors accessible over this interface.

detail

(Optional) Displays information in long form.

graceful-restart

(Optional) Displays per-neighbor graceful restart information.

Defaults

This command displays information about LDP neighbors for the default routing domain if you do not specify the optional vrf keyword.

Command Modes

User EXEC
Privileged EXEC

Command History

Release

Modification

11.1CT

This command was introduced.

12.0(10)ST

The command was modified to reflect Multiprotocol Label Switching (MPLS) Internet Engineering Task Force (IETF) command syntax and terminology.

12.0(14)ST

This command was modified to reflect MPLS VPN support for LDP and the vrf and all keywords were added.

12.1(8a)E

This command was integrated into Cisco IOS Release 12.1(8a)E.

12.2(2)T

This command was integrated into Cisco IOS Release 12.2(2)T.

12.0(22)S

This command was integrated into Cisco IOS Release 12.0(22)S.

12.2(14)S

This command was integrated into Cisco IOS Release 12.2(14)S.

12.0(26)S

The detail keyword was updated to display information about inbound filtering.

12.2(25)S

The graceful-restart keyword was added.

12.3(14)T

The command output was updated so that the detail keyword displays information about MPLS LDP Session Protection.

12.2(18)SXE

This command was integrated into Cisco IOS Release 12.2(18)SXE.

12.2(28)SB

The detail keyword was updated to include Message Digest 5 (MD5) password information and the command was implemented on the Cisco 10000 series routers.

12.2(33)SRA

This command was integrated into Cisco IOS Release 12.2(33)SRA.

12.2(33)SXH

This command was integrated into Cisco IOS Release 12.2(33)SXH.

Usage Guidelines

The show mpls ldp neighbor command can provide information about all LDP neighbors, or the information can be limited to the following:

•Neighbor with specific IP address

•LDP neighbors known to be accessible over a specific interface

Note This command displays information about LDP and Tag Distribution Protocol (TDP) neighbor sessions.

Examples

For explanations of the significant fields shown in the displays, see Table 9.

The following is sample output from the show mpls ldp neighbor command:
Router# show mpls ldp neighbor
Peer LDP Ident: 10.0.7.7:2; Local LDP Ident 10.1.1.1:1
        TCP connection: 10.0.7.7.11032 - 10.1.1.1.646
        State: Oper; Msgs sent/rcvd: 5855/6371; Downstream on demand
        Up time: 13:15:09
        LDP discovery sources:
          ATM3/0.1
Peer LDP Ident: 10.1.1.1:0; Local LDP Ident 10.1.1.1:0
        TCP connection: 10.1.1.1.646 - 10.1.1.1.11006
        State: Oper; Msgs sent/rcvd: 4/411; Downstream
        Up time: 00:00:52
        LDP discovery sources:
          Ethernet1/0/0
        Addresses bound to peer LDP Ident:
          10.0.0.29        10.1.1.1         10.0.0.199      10.10.1.1
          10.205.0.9      
The following is sample output from the show mpls ldp neighbor command, in which duplicate addresses are detected. They indicate an error because a given address should be bound to only one peer.
Router# show mpls ldp neighbor 
Peer LDP Ident: 10.0.7.7:2; Local LDP Ident 10.1.1.1:1
        TCP connection: 10.0.7.7.11032 - 10.1.1.1.646
        State: Oper; Msgs sent/rcvd: 5855/6371; Downstream on demand
        Up time: 13:15:09
        LDP discovery sources:
          ATM3/0.1
Peer LDP Ident: 10.1.1.1:0; Local LDP Ident 10.1.1.1:0
        TCP connection: 10.1.1.1.646 - 10.1.1.1.11006
        State: Oper; Msgs sent/rcvd: 4/411; Downstream
        Up time: 00:00:52
        LDP discovery sources:
          Ethernet1/0/0
        Addresses bound to peer LDP Ident:
          10.0.0.29 10.1.1.1 10.0.0.199 10.10.1.1
          10.205.0.9 
        Duplicate Addresses advertised by peer: 
          10.10.8.111
The following is sample output from the show mpls ldp neighbor vrf vpn10 command, which displays the LDP neighbor information for the specified VPN routing and forwarding instance named vpn10:
Router# show mpls ldp neighbor vrf vpn10
Peer LDP Ident:10.14.14.14:0; Local LDP Ident 10.29.0.2:0
        TCP connection:10.14.14.14.646 - 10.29.0.2.11384
        State:Oper; Msgs sent/rcvd:1423/800; Downstream
        Up time:02:38:11
        LDP discovery sources:
          ATM3/0/0.10
        Addresses bound to peer LDP Ident:
          10.3.36.9       10.7.0.1        10.14.14.14     10.13.0.1       
          10.15.0.1       10.17.0.1       10.19.0.1       10.21.0.1       
          10.23.0.1       10.25.0.1       10.27.0.1       10.29.0.1       
          10.31.0.1       10.33.0.1       10.35.0.1       10.37.0.1       
          10.39.0.1       10.41.0.1       10.43.0.1       10.45.0.1       
          10.47.0.1       10.49.0.1       10.51.0.1       10.53.0.1       
          10.55.0.1       10.57.0.1       10.59.0.1       10.61.0.1       
          10.63.0.1       10.65.0.1       10.67.0.1       10.69.0.1       
          10.71.0.1       10.73.0.1       10.75.0.1       10.77.0.1       
          10.79.0.1       10.81.0.1       10.83.0.1       10.85.0.1       
          10.87.0.1       10.89.0.1       10.91.0.1       10.93.0.1       
          10.95.0.1       10.97.0.1       10.99.0.1       10.101.0.1      
          10.103.0.1      10.105.0.1      10.107.0.1      10.109.0.1      
          10.4.0.2        10.3.0.2        
The following shows sample output from the show mpls ldp neighbor detail command, which displays information about inbound filtering:
Router# show mpls ldp neighbor vrf vpn1 detail
 Peer LDP Ident: 10.13.13.13:0; Local LDP Ident 10.33.0.2:0
   TCP connection: 10.13.13.13.646 - 10.33.0.2.31581
   State: Oper; Msgs sent/rcvd: 11/10; Downstream; Last TIB rev sent 13
   Up time: 00:02:25; UID: 26; Peer Id 0;
   LDP discovery sources:
    Ethernet1/0/2; Src IP addr: 10.33.0.1 
     holdtime: 15000 ms, hello interval: 5000 ms
   Addresses bound to peer LDP Ident:
    10.3.105.1       10.13.13.13     10.33.0..1        
   Peer holdtime: 180000 ms; KA interval: 60000 ms; Peer state: estab
   LDP inbound filtering accept acl:1
 Peer LDP Ident: 10.14.14.14:0; Local LDP Ident 10.33.0.2:0
   TCP connection: 10.14.14.14.646 - 10.33.0.2.31601
   State: Oper; Msgs sent/rcvd: 10/9; Downstream; Last TIB rev sent 13
   Up time: 00:01:17; UID: 29; Peer Id 3;
   LDP discovery sources:
    Ethernet1/0/3; Src IP addr: 10.33.0.1 
     holdtime: 15000 ms, hello interval: 5000 ms
   Addresses bound to peer LDP Ident:
    10.3.104.1       10.14.14.14     10.32.0.1        
   Peer holdtime: 180000 ms; KA interval: 60000 ms; Peer state: estab
   LDP inbound filtering accept acl:1 
The following is sample output from the show mpls ldp neighbor all command, which displays the LDP neighbor information for all VPN routing and forwarding instances, including those in the default routing domain. In this example, note that the same neighbor LDP ID (10.14.14.14) appears in all the listed VRF interfaces, highlighting the fact that the same IP address can coexist in different VPN routing and forwarding instances.
Router# show mpls ldp neighbor all 
Peer TDP Ident:10.11.11.11:0; Local TDP Ident 10.12.12.12:0
        TCP connection:10.11.11.11.711 - 10.12.12.12.11003
        State:Oper; PIEs sent/rcvd:185/187; Downstream
        Up time:02:40:02
        TDP discovery sources:
          ATM1/1/0.1
        Addresses bound to peer TDP Ident:
          10.3.38.3        10.1.0.2        10.11.11.11     
VRF vpn1:
    Peer LDP Ident:10.14.14.14:0; Local LDP Ident 10.7.0.2:0
        TCP connection:10.14.14.14.646 - 10.7.0.2.11359
        State:Oper; Msgs sent/rcvd:952/801; Downstream
        Up time:02:38:49
        LDP discovery sources:
          ATM3/0/0.1
        Addresses bound to peer LDP Ident:
          10.3.36.9       10.7.0.1        10.14.14.14     10.13.0.1       
          10.15.0.1       10.17.0.1       10.19.0.1       10.21.0.1       
          10.23.0.1       10.25.0.1       10.27.0.1       10.29.0.1       
          10.31.0.1       10.33.0.1       10.35.0.1       10.37.0.1       
          10.39.0.1       10.41.0.1       10.43.0.1       10.45.0.1       
          10.47.0.1       10.49.0.1       10.51.0.1       10.53.0.1       
          10.55.0.1       10.57.0.1       10.59.0.1       10.61.0.1       
          10.63.0.1       10.65.0.1       10.67.0.1       10.69.0.1       
          10.71.0.1       10.73.0.1       10.75.0.1       10.77.0.1       
          10.79.0.1       10.81.0.1       10.83.0.1       10.85.0.1       
          10.87.0.1       10.89.0.1       10.91.0.1       10.93.0.1       
          10.95.0.1       10.97.0.1       10.99.0.1       10.101.0.1      
          10.103.0.1      10.105.0.1      10.107.0.1      10.109.0.1      
          10.4.0.2        10.3.0.2        
VRF vpn2:
    Peer LDP Ident:10.14.14.14:0; Local LDP Ident 10.13.0.2:0
        TCP connection:10.14.14.14.646 - 10.13.0.2.11361
        State:Oper; Msgs sent/rcvd:964/803; Downstream
        Up time:02:38:50
        LDP discovery sources:
          ATM3/0/0.2
        Addresses bound to peer LDP Ident:
          10.3.36.9       10.7.0.1        10.14.14.14     10.13.0.1       
          10.15.0.1       10.17.0.1       10.19.0.1       10.21.0.1       
          10.23.0.1       10.25.0.1       10.27.0.1       10.29.0.1       
          10.31.0.1       10.33.0.1       10.35.0.1       10.37.0.1       
          10.39.0.1       10.41.0.1       10.43.0.1       10.45.0.1       
          10.47.0.1       10.49.0.1       10.51.0.1       10.53.0.1       
          10.55.0.1       10.57.0.1       10.59.0.1       10.61.0.1       
          10.63.0.1       10.65.0.1       10.67.0.1       10.69.0.1       
          10.71.0.1       10.73.0.1       10.75.0.1       10.77.0.1       
          10.79.0.1       10.81.0.1       10.83.0.1       10.85.0.1       
          10.87.0.1       10.89.0.1       10.91.0.1       10.93.0.1       
          10.95.0.1       10.97.0.1       10.99.0.1       10.101.0.1      
          10.103.0.1      10.105.0.1      10.107.0.1      10.109.0.1      
          10.4.0.2        10.3.0.2        
VRF vpn3:
    Peer LDP Ident:10.14.14.14:0; Local LDP Ident 10.15.0.2:0
        TCP connection:10.14.14.14.646 - 10.15.0.2.11364
        State:Oper; Msgs sent/rcvd:1069/800; Downstream
        Up time:02:38:52
        LDP discovery sources:
          ATM3/0/0.3
        Addresses bound to peer LDP Ident:
          10.3.36.9       10.17.0.1       10.14.14.14     10.13.0.1       
          10.15.0.1       10.17.0.1       10.19.0.1       10.21.0.1       
          10.23.0.1       10.25.0.1       10.27.0.1       10.29.0.1       
          10.31.0.1       10.33.0.1       10.35.0.1       10.37.0.1       
          10.39.0.1       10.41.0.1       10.43.0.1       10.45.0.1       
          10.47.0.1       10.49.0.1       10.51.0.1       10.53.0.1       
          10.55.0.1       10.57.0.1       10.59.0.1       10.61.0.1       
          10.63.0.1       10.65.0.1       10.67.0.1       10.69.0.1       
          10.71.0.1       10.73.0.1       10.75.0.1       10.77.0.1       
          10.79.0.1       10.81.0.1       10.83.0.1       10.85.0.1       
          10.87.0.1       10.89.0.1       10.91.0.1       10.93.0.1       
          10.95.0.1       10.97.0.1       10.99.0.1       10.101.0.1      
          10.103.0.1      10.105.0.1      10.107.0.1      10.109.0.1      
          10.4.0.2        10.3.0.2 
VRF vpn4:
    Peer LDP Ident:10.14.14.14:0; Local LDP Ident 10.17.0.2:0
        TCP connection:10.14.14.14.646 - 10.17.0.2.11366
        State:Oper; Msgs sent/rcvd:1199/802; Downstream
The following example shows the Graceful Restart status of the LDP neighbors:
Router# show mpls ldp neighbor graceful-restart
Peer LDP Ident: 10.20.20.20:0; Local LDP Ident 10.17.17.17:0
   TCP connection: 10.20.20.20.16510 - 10.17.17.17.646
    State: Oper; Msgs sent/rcvd: 8/18; Downstream
    Up time: 00:04:39
    Graceful Restart enabled; Peer reconnect time (msecs): 120000
Peer LDP Ident: 10.19.19.19:0; Local LDP Ident 10.17.17.17:0
    TCP connection: 10.19.19.19.11007 - 10.17.17.17.646
    State: Oper; Msgs sent/rcvd: 8/38; Downstream
    Up time: 00:04:30
    Graceful Restart enabled; Peer reconnect time (msecs): 120000
The following sample output from the show mpls ldp neighbor detail command displays information about the MD5 password configuration:
Router# show mpls ldp neighbor detail
    Peer LDP Ident: 10.3.3:0; Local LDP Ident 10.1.1.1:0
        TCP connection: 10.3.3.3.11018 - 10.1.1.1.646
        Password: required, neighbor, in use
        State: Oper; Msgs sent/rcvd: 167/167; Downstream; Last TIB rev sent 9
        Up time: 02:24:02; UID: 5; Peer Id 3;
        LDP discovery sources:
          Targeted Hello 10.1.1.1 -> 10.3.3.3, passive;
            holdtime: 90000 ms, hello interval: 10000 ms
        Addresses bound to peer LDP Ident:
          10.3.3.3         10.0.30.3
        Peer holdtime: 180000 ms; KA interval: 60000 ms; Peer state: estab
    Peer LDP Ident: 10.4.4.4:0; Local LDP Ident 10.1.1.1:0
        TCP connection: 10.4.4.4.11017 - 10.1.1.1.646
        Password: not required, none, stale
        State: Oper; Msgs sent/rcvd: 9/9; Downstream; Last TIB rev sent 9
        Up time: 00:05:35; UID: 6; Peer Id 1;
        LDP discovery sources:
          Ethernet1/0; Src IP addr: 10.0.20.4 
            holdtime: 15000 ms, hello interval: 5000 ms
        Addresses bound to peer LDP Ident:
          10.0.40.4       10.4.4.4         10.0.20.4 
        Peer holdtime: 180000 ms; KA interval: 60000 ms; Peer state: estab
Table 9 describes the significant fields shown in the displays.

Table 9 show mpls ldp neighbor Field Descriptions

Field

Description

Peer LDP Ident

LDP (or TDP) identifier of the neighbor (peer) for this session.

Local LDP Ident

LDP (or TDP) identifier for the local label switch router (LSR) for this session.

TCP connection

TCP connection used to support the LDP session, shown in the following format:

•peer IP address.peer port

•local IP address.local port

Password

Indicates if password protection is being used. Password status is as follows:

•Required or not required—Indicates whether password configuration is required.

•Neighbor, none, option #, or fallback—Indicates the password source when the password was configured.

•In use (current) or stale (previous)—Indicates the current LDP session password usage status.

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.

Downstream on demand

Indicates that the Downstream on Demand method of label distribution is being used for this LDP session. When the Downstream on Demand method is used, an LSR advertises its locally assigned (incoming) labels to its LDP peer only when the peer requests them.

Downstream

Indicates that the downstream method of label distribution is being used for this LDP session. When the downstream method is used, an LSR advertises all of its locally assigned (incoming) labels to its LDP peer (subject to any configured access list restrictions).

Up time

Length of time (in hours, minutes, seconds) the LDP session has existed.

Graceful Restart enabled

Indicates whether the LDP session has Graceful Restart enabled.

Peer reconnect time

The length of time, in milliseconds (msecs), the peer router waits for a router to reconnect.

LDP discovery sources

Sources of LDP discovery activity that led to the establishment of this LDP session.

Targeted Hello

Lists the platforms to which targeted hello messages are being sent:

•The active field indicates that this LSR has initiated targeted hello messages.

•The passive field indicates that the neighbor LSR has initiated targeted hello messages and that this LSR is configured to respond to the targeted hello messages from the neighbor.

holdtime

Period of time, in milliseconds (ms), a discovered LDP neighbor is remembered without receipt of an LDP hello message from the neighbor.

hello interval

Period of time, in milliseconds (ms), between the sending of consecutive hello messages.

Addresses bound to peer LDP Ident

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 Label Forwarding Information Base (LFIB).

Duplicate Addresses advertised by peer

IP addresses that are bound to another peer. They indicate an error because a given address should be bound to only one peer.

Peer holdtime

The time, in milliseconds (ms), that the neighbor session is retained without the receipt of an LDP message from the neighbor.

KA Interval

Keep Alive Interval. The amount of time, in milliseconds (ms), that a router lets pass without sending an LDP message to its neighbor. If this time elapses and the router has nothing to send, it sends a Keep Alive message.

Peer state

State of the peer; estab means established.

LDP inbound filtering accept acl:1

Access list that is permitted for inbound label binding filtering.

Related Commands

Command

Description

show mpls ldp discovery

Displays the status of the LDP discovery process.

Feature Information for NSF/SSO - MPLS LDP and LDP Graceful Restart

Table 10 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 10 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.

Table 10 Feature Information for NSF/SSO - MPLS LDP and LDP Graceful Restart

Feature Name

Releases

Feature Information

NSF/SSO - MPLS LDP and LDP Graceful Restart

12.2(25)S
12.2(28)SB
12.2(33)SRA
12.2(33)SXH

LDP NSF allows a Route Processor to recover from disruption in service without losing its MPLS forwarding state.

In 12.2(25)S, this feature was introduced on Cisco 7500 series routers.

In 12.2(28)SB, this feature was integrated into Cisco IOS Release 12.2(28)SB and implemented on Cisco 10000 series routers.

In 12.2(33)SRA, this feature was integrated into Cisco IOS Release 12.2(33)SRA.

In 12.2(33)SXH, this feature was integrated into Cisco IOS Release 12.2(33)SXH.

Any Internet Protocol (IP) addresses used in this document are not intended to be actual addresses. Any examples, command display output, and figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses in illustrative content is unintentional and coincidental.

© 2004-2007 Cisco Systems, Inc. All rights reserved.

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Cisco IOS Software Releases 12.2 S

NSF/SSO - MPLS LDP and LDP Graceful Restart

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Table Of Contents

NSF/SSO - MPLS LDP and LDP Graceful Restart

Contents

Prerequisites for NSF/SSO - MPLS LDP and LDP Graceful Restart

Restrictions for NSF/SSO - MPLS LDP and LDP Graceful Restart

Information About NSF/SSO - MPLS LDP and LDP Graceful Restart

How NSF/SSO - MPLS LDP and LDP Graceful Restart Works

What Happens During an LDP Restart and an LDP Session Reset

How a Route Processor Advertises That It Supports NSF/SSO - MPLS LDP and LDP Graceful Restart

What Happens if a Route Processor Does Not Have LDP Graceful Restart

Checkpointing

Troubleshooting Tips

How to Configure and Use NSF/SSO - MPLS LDP and LDP Graceful Restart

Configuring MPLS LDP Graceful Restart

Prerequisites

SUMMARY STEPS

DETAILED STEPS

Verifying the Configuration

SUMMARY STEPS

DETAILED STEPS

Configuration Examples for LDP NSF

Configuring NSF/SSO - MPLS LDP and LDP Graceful Restart: Example

Additional References

Related Documents

Standards

MIBs

RFCs

Technical Assistance

Command Reference

debug mpls ldp graceful-restart

Syntax Description

Defaults

Command Modes

Command History

Usage Guidelines

Examples

Related Commands

mpls label protocol (global configuration)

Syntax Description

Defaults

Command Modes

Command History

Usage Guidelines

Examples

Related Commands

mpls ldp graceful-restart

Syntax Description

Defaults

Command Modes

Command History

Usage Guidelines

Examples

Related Commands

mpls ldp graceful-restart timers forwarding-holding

Syntax Description

Defaults

Command Modes

Command History

Usage Guidelines

Examples

Related Commands

mpls ldp graceful-restart timers max-recovery

Syntax Description

Defaults

Command Modes

Command History

Usage Guidelines

Examples

Related Commands

mpls ldp graceful-restart timers neighbor-liveness

Syntax Description

Defaults

Command Modes

Command History

Usage Guidelines

Examples