Cisco ASR 9000 Series Aggregation Services Router MPLS Command Reference, Release 4.1
MPLS Label Distribution Protocol Commands
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Contents

MPLS Label Distribution Protocol Commands

This module describes the commands used to configure Label Distribution Protocol (LDP) in a Multiprotocol Label Switching (MPLS) network on the Cisco ASR 9000 Series Routers.

LDP provides a standard methodology for hop-by-hop (or dynamic label) distribution in an MPLS network by assigning labels to routes that have been chosen by the underlying Interior Gateway Protocol (IGP) routing protocols. The resulting labeled paths, called label switch paths (LSPs), forward labeled traffic across an MPLS backbone.

LDP also provides the means for label switching routers (LSRs) to request, distribute, and release label prefix binding information to peer routers in a network. LDP enables LSRs to discover potential peers and establish LDP sessions with those peers to exchange label binding information.

For detailed information about MPLS concepts, configuration tasks, and examples, see Cisco ASR 9000 Series Aggregation Services Router MPLS Configuration Guide.

backoff

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

backoff initial maximum

no backoff

Syntax Description

initial

Initial backoff delay, in seconds. Range is 5 to 2147483 .

maximum

Maximum backoff delay, in seconds. Range is 5 to 2147483 .

Command Default

initial : 15

maximum : 120

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router# configure
RP/0/RSP0/CPU0:router(config)# mpls ldp
RP/0/RSP0/CPU0:router(config-ldp)# backoff 30 240
  

Related Commands

Command

Description

show mpls ldp backoff

Displays information about the configured session setup backoff parameters and LDP peers.

show mpls ldp parameters

Displays current LDP parameter settings.

clear mpls ldp msg-counters neighbor

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

clear mpls ldp msg-counters neighbor { ip-address | all }

Syntax Description

ip-address

LSR or LDP ID of the neighbor.

all

Clears LDP message counters for all neighbors.

Command Default

No default behavior or values

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router# clear mpls ldp msg-counters neighbor 10.20.20.20

Related Commands

Command

Description

show mpls ldp statistics msg-counters

Displays statistics about the type and count of the messages sent and received from neighbors.

clear mpls ldp neighbor

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

clear mpls ldp neighbor [ip-address]

Syntax Description

ip-address

(Optional) Neighbor IP address or LDP ID.

Command Default

No default behavior or values

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router# clear mpls ldp neighbor 10.20.20.20

Related Commands

Command

Description

show mpls ldp neighbor

Displays information about LDP neighbors.

clear mpls ldp forwarding

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

clear mpls ldp forwarding [ IP -address ]

Syntax Description

IP-address

(Optional) IPv4 address, specified in four-part, dotted-decimal notation.

Command Default

No default behavior or values

Command Modes

EXEC

Command History

Release

Modification

Release 4.0.1

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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


RP/0/RSP0/CPU0:router# clear mpls ldp forwarding

Related Commands

Command

Description

show mpls ldp forwarding

Displays the LDP forwarding state installed in MPLS forwarding.

show mpls forwarding

Displays the contents of the MPLS Label Forwarding Information Base (LFIB).

graceful-restart (MPLS LDP)

Configures the LDP graceful restart feature.

show mpls ldp bindings

Displays the contents of LDP LIB.

default-route

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

default-route

no default-route

Syntax Description

This command has no arguments or keywords.

Command Default

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

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router(config-ldp)# default-route

Related Commands

Command

Description

show mpls ldp bindings

Displays LDP label bindings.

show mpls ldp forwarding

Displays LDP installed forwarding state.

discovery hello

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

discovery hello { holdtime seconds | interval seconds }

no discovery hello { holdtime | interval }

Syntax Description

holdtime

Sets the time, in seconds, a discovered LDP neighbor is remembered without receipt of an LDP hello message from the neighbor. Default is 15.

interval

Sets the time, in seconds, between consecutive hello messages. Default is 5.

seconds

Time value, in seconds. Range is 1 to 65535 (65535 means infinite).

Command Default

holdtime: 15

interval: 5

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router(config-ldp)# discovery hello holdtime 30
  

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

RP/0/RSP0/CPU0:router(config-ldp)# discovery hello interval 10

Related Commands

Command

Description

discovery targeted-hello

Configures targeted-hello messages.

discovery instance-tlv disable

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

discovery instance-tlv disable

no discovery instance-tlv disable

Syntax Description

This command has no arguments or keywords.

Command Default

No default behavior or values

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router# configure
RP/0/RSP0/CPU0:router(config)# mpls ldp
RP/0/RSP0/CPU0:router(config-ldp)# discovery instance-tlv disable

Related Commands

Command

Description

discovery targeted-hello

Configures targeted-hello messages.

discovery targeted-hello

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

discovery targeted-hello { accept | [ from acl ] | holdtime seconds | interval seconds }

no discovery targeted-hello { accept | holdtime | interval }

Syntax Description

accept

Accepts targeted hellos from any source.

from acl

(Optional) Accepts targeted hellos from LDP peers as permitted by the access-list.

holdtime

Configures the time a discovered LDP neighbor is remembered without receipt of an LDP hello message from a neighbor.

interval

Displays time between consecutive hello messages.

seconds

Time value, in seconds. Range is 1 to 65535.

Command Default

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

holdtime : 90

interval : 10

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

LDP supports IPv4 standard access lists only.

Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router(config-ldp)# discovery targeted-hello holdtime 45
  

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

RP/0/RSP0/CPU0:router(config-ldp)# discovery targeted-hello interval 5
  

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

RP/0/RSP0/CPU0:router(config-ldp)# discovery targeted-hello accept

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

RP/0/RSP0/CPU0:router(config)# ipv4 access-list peer_acl_10
RP/0/RSP0/CPU0:router(config-ipv4-acl)# permit 10.1.1.1
RP/0/RSP0/CPU0:router(config-ipv4-acl)# permit 10.2.2.2
RP/0/RSP0/CPU0:router(config-ldp)# discovery targeted-hello accept from peer_acl_10
  
 

Related Commands

Command

Description

show mpls ldp discovery

Displays LDP discovery information.

show mpls ldp parameters

Displays LDP parameters information.

discovery transport-address

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

discovery transport-address { ip-address | interface }

no discovery transport-address { ip-address | interface }

Syntax Description

ip-address

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

interface

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

Command Default

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

Command Modes

MPLS LDP interface configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

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

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


Note


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


Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router(config-ldp)# interface POS 0/1/0/0 
RP/0/RSP0/CPU0:router(config-ldp-if)# discovery transport-address 10.10.3.1
  
RP/0/RSP0/CPU0:router# show mpls ldp neighbor
  
  Peer LDP Identifier: 10.44.44.44:0
    TCP connection: 10.44.44.44:65520 - 10.10.3.1:646
    Graceful Restart: Yes (Reconnect Timeout: 15 sec, Recovery: 180 sec)
    State: Oper; Msgs sent/rcvd: 13/9
    Up time: 00:00:11
    LDP Discovery Sources: 
         POS 0/1/0/0
    Addresses bound to this peer:
      10.10.3.2       10.44.44.44
  

Related Commands

Command

Description

show mpls ldp discovery

Displays the status of the LDP discovery process.

show mpls ldp neighbor

Displays information about LDP neighbors.

downstream-on-demand

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

downstream-on-demand with access-list

nodownstream-on-demand with access-list

Syntax Description

with

Displays access list of LDP peers.

access-list

IP access-list name.

Command Default

No default behavior or values

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 4.0.1

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Task ID

Task ID Operation

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router(config-ldp)# downstream-on-demand with access-list 
  

  

Related Commands

Command

Description

graceful-restart (MPLS LDP)

Configures the LDP graceful restart feature.

show mpls ldp bindings

Displays the contents of LDP LIB.

explicit-null

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

explicit-null [ to peer-acl | for prefix-acl [ to peer-acl ] ]

no explicit-null

Syntax Description

to peer-acl

(Optional) Specifies LDP peers for which explicit-null is advertised instead of implicit-null. Range is 1 to 99.

for prefix-acl

(Optional) Specifies prefixes for which explicit-null is advertised instead of implicit-null. Range is 1 to 99.

Command Default

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

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 5.0.0

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

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

LDP supports IPv4 standard access lists only.

Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router(config-ldp)# explicit-null

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

RP/0/RSP0/CPU0:router(config)# ipv4 access-list pfx_acl_192_168
RP/0/RSP0/CPU0:router(config-ipv4-acl)# permit 192.168.0.0
RP/0/RSP0/CPU0:router(config-ldp)# explicit-null for pfx_acl_192_168
  

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

RP/0/RSP0/CPU0:router(config)# ipv4 access-list peer_acl_10
RP/0/RSP0/CPU0:router(config-ipv4-acl)# permit 10.1.1.1
RP/0/RSP0/CPU0:router(config-ipv4-acl)# permit 10.2.2.2
  
RP/0/RSP0/CPU0:router(config-ldp)# explicit-null to peer_acl_10
  

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

RP/0/RSP0/CPU0:router(config-ldp)# explicit-null for pfx_acl_192_168 to peer_acl_10

Related Commands

Command

Description

show mpls ldp bindings

Displays the contents of LDP LIB.

show mpls ldp forwarding

Displays the contents of the LDP forwarding database.

show mpls ldp parameters

Displays current LDP parameter settings.

graceful-restart (MPLS LDP)

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

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

no graceful-restart [ reconnect-timeout | forwarding-state-holdtime ]

Syntax Description

reconnect-timeout seconds

(Optional) Configures the time that the local LDP sends to its graceful restartable peer, indicating how long its neighbor should wait for reconnection in the event of a LDP session failure, in seconds. Range is 60 to 1800.

forwarding-state-holdtime seconds

(Optional) Configures the time the local forwarding state is preserved (without being reclaimed) after the local LDP control plane restarts, in seconds. Range is 60 to 1800.

Command Default

By default, graceful restart is disabled.

reconnect-timeout: 120

forwarding-state-holdtime: 180

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

The maximum value for the seconds argument is 1800.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

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

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


Note


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


Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router(config-ldp)# graceful-restart
  
RP/0/RSP0/CPU0:router:Apr  3 10:56:05.392 : mpls_ldp[336]: %ROUTING-LDP-5-NBR_CHANGE : Nbr 2.2.2.2:0, DOWN 
RP/0/RSP0/CPU0:router:Apr  3 10:56:05.392 : mpls_ldp[336]: %ROUTING-LDP-5-NBR_CHANGE : Nbr 3.3.3.3:0, DOWN 
RP/0/RSP0/CPU0:router:Apr  3 10:56:09.525 : mpls_ldp[336]: %ROUTING-LDP-5-NBR_CHANGE : Nbr 3.3.3.3:0, UP 
RP/0/RSP0/CPU0:router:Apr  3 10:56:11.114 : mpls_ldp[336]: %ROUTING-LDP-5-NBR_CHANGE : Nbr 2.2.2.2:0, UP 
  
RP/0/RSP0/CPU0:router# show mpls ldp neighbor brief
  
  Peer              GR Up Time         Discovery Address
  ----------------- -- --------------- --------- -------
  3.3.3.3:0         Y  00:01:04                3       8
  2.2.2.2:0         N  00:01:02                2       5
  
RP/0/RSP0/CPU0:router# show mpls ldp graceful-restart
  
    Forwarding State Hold timer : Not Running
    GR Neighbors                : 1
  
     Neighbor ID      Up  Connect Count  Liveness Timer      Recovery Timer    
     ---------------  --  -------------  ------------------  ------------------
     3.3.3.3          Y        1                -                   - 

Related Commands

Command

Description

show mpls ldp forwarding

Displays the contents of the LDP forwarding database.

show mpls ldp graceful-restart

Displays information related to graceful restart.

show mpls ldp neighbor

Displays information about LDP neighbors.

show mpls ldp parameters

Displays current LDP parameter settings.

show mpls ldp summary

Displays summarized information regarding the LDP process.

holdtime (MPLS LDP)

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

holdtime seconds

no holdtime

Syntax Description

seconds

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

Command Default

seconds: 180

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router(config-ldp)# holdtime 30

Related Commands

Command

Description

show mpls ldp parameters

Displays current LDP parameter settings.

igp auto-config disable

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

igp auto-config disable

no igp auto-config disable

Syntax Description

This command has no arguments or keywords.

Command Default

No default behavior or values

Command Modes

MPLS LDP interface configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router(config)# mpls ldp
RP/0/RSP0/CPU0:router(config-ldp)# interface pos 0/1/0/3
RP/0/RSP0/CPU0:router(config-ldp-if)# igp auto-config disable
  

Related Commands

Command

Description

show mpls ldp interface

Displays information about LDP-enabled interfaces.

igp sync delay

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

igp sync delay seconds

no igp sync delay

Syntax Description

seconds

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

Command Default

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

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router# configure
RP/0/RSP0/CPU0:router(config)# mpls ldp
RP/0/RSP0/CPU0:router(config-ldp)# igp sync delay 30
  

Related Commands

Command

Description

show mpls ldp igp sync

Displays LDP IGP sync information for link(s).

interface (MPLS LDP)

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

interface type interface-path-id

no interface type interface-path-id

Syntax Description

type

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

interface-path-id

Physical interface or a virtual interface.

Note   

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

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

Command Default

No default behavior or values

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.9.0

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

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


Note


You cannot enable LDP on loopback interfaces.


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

Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router# configure
RP/0/RSP0/CPU0:router(config)# mpls ldp
RP/0/RSP0/CPU0:router(config-ldp)# interface POS 0/1/0/0
RP/0/RSP0/CPU0:router(config-ldp-if)#
  

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

RP/0/RSP0/CPU0:router# configure
RP/0/RSP0/CPU0:router(config)# mpls ldp
RP/0/RSP0/CPU0:router(config-ldp)# interface tunnel-te 123
RP/0/RSP0/CPU0:router(config-ldp-if)#
  

Related Commands

Command

Description

show mpls ldp parameters

Displays current LDP parameter settings.

show mpls ldp neighbor

Displays LDP neighbor session parameters.

label accept

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

label accept for prefix-acl from ip-address

no label accept for prefix-acl from ip-address

Syntax Description

for prefix-acl

Accepts and retains remote bindings for prefixes that are permitted by the prefix access list prefix-acl argument.

from ip-address

Displays the peer IP address.

Command Default

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

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

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

LDP supports IPv4 standard access lists only.


Note


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


Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

The following example shows how to configure inbound label filtering policy. In this example, an LSR is configured to accept and retain label bindings for prefixes 192.168.1.1 (pfx_acl_1) from peer 1.1.1.1, prefix 192.168.2.2 (pfx_acl_2) from peer 2.2.2.2, and prefixes 192.168.1.1, 192.168.2.2, 192.168.3.3 (pfx_acl_3) from peer 3.3.3.3:

RP/0/RSP0/CPU0:router(config-ldp)# label accept
RP/0/RSP0/CPU0:router(config-ldp-lbl-acpt)# for pfx_acl_1 from 1.1.1.1
RP/0/RSP0/CPU0:router(config-ldp-lbl-acpt)# for pfx_acl_2 from 2.2.2.2
RP/0/RSP0/CPU0:router(config-ldp-lbl-acpt)# for pfx_acl_3 from 3.3.3.3

Related Commands

Command

Description

label advertise

Controls advertisement of LDP local label bindings (outbound label filtering).

clear mpls ldp neighbor

Resets LDP neighbor sessions.

show mpls ldp bindings

Displays LDP binding information.

label advertise

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

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

no label advertise [ disable | for prefix-acl [ to peer-acl ] | interface type interface-path-id ]

Syntax Description

disable

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

for prefix-acl

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

to peer-acl

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

interface

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

type

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

interface-path-id

Physical interface or a virtual interface.

Note   

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

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

Command Default

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

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

  • Every command has a prefix-acl or peer-acl pair associated with it, as follows:
    • In the absence of the for or to keywords, the access list pair is (none, none).
    • When using the for keyword without the to keyword, the access list is (prefix-acl, none).
  • A prefix can have a maximum of one (prefix-acl, peer-acl) pair, as follows:
    • A (prefix-acl, peer-acl) pair applies to a prefix only if the prefix-acl matches the prefix. A match occurs if the prefix-acl permits the prefix.
    • If more than one (prefix-acl, peer-acl) pair from multiple label advertise commands matches a prefix, the (prefix-acl, peer-acl) pair in the first command applies to the prefix.
  • When an LSR is ready to advertise a label for a prefix, the LSR determines whether a (prefix-acl, peer-acl) pair applies to the prefix.
    • If none applies, and if the disable keyword has been configured for the command, the label for the prefix is not advertised to any peer; otherwise, the label is advertised to all peers.
    • If a (prefix-acl, peer-acl) pair applies to the prefix, and if the prefix-acl denies the prefix, the label is not advertised to any peer.
    • If the prefix-acl permits the prefix and the peer-acl is none (that is, the command that applies to the prefix is an label advertise for prefix-acl command without the to keyword), the label is advertised to all peers.
    • If the prefix-acl permits the prefix and there is a peer-acl, the label is advertised to all peers permitted by the peer-acl.
    Normally, LDP advertises labels for non-BGP routes present in the routing table. Additionally, LDP advertises labels from /32 IP addresses on Loopback interfaces and does not advertise /32 addresses for other non-Loopback interfaces. To control advertisement of labels for /32 IP addresses on these interfaces, use the label advertise interface command. LDP supports IPv4 standard access lists only.

    Note


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


Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router(config-ldp)# label advertise
RP/0/RSP0/CPU0:router(config-ldp-lbl-advt)# disable

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

RP/0/RSP0/CPU0:router(config)# ipv4 access-list pfx_acl_1
RP/0/RSP0/CPU0:router(config-ipv4-acl)# permit 10.1.1.0
RP/0/RSP0/CPU0:router(config-ipv4-acl)# permit 20.1.1.0

RP/0/RSP0/CPU0:router(config-ldp)# label advertise
RP/0/RSP0/CPU0:router(config-ldp-lbl-advt)# disable
RP/0/RSP0/CPU0:router(config-ldp-lbl-advt)# for pfx_acl_1

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

RP/0/RSP0/CPU0:router(config)# ipv4 access-list pfx_acl_10
RP/0/RSP0/CPU0:router(config-ipv4-acl)# permit 10.0.0.0
  
RP/0/RSP0/CPU0:router(config)# ipv4 access-list pfx_acl_20
RP/0/RSP0/CPU0:router(config-ipv4-acl)# permit 20.0.0.0
  
RP/0/RSP0/CPU0:router(config)# ipv4 access-list peer_acl_10
RP/0/RSP0/CPU0:router(config-ipv4-acl)# permit 10.1.1.1
RP/0/RSP0/CPU0:router(config-ipv4-acl)# permit 10.2.2.2
  
RP/0/RSP0/CPU0:router(config)# ipv4 access-list peer_acl_20
RP/0/RSP0/CPU0:router(config-ipv4-acl)# permit 20.1.1.1 
  
RP/0/RSP0/CPU0:router(config-ldp)# label advertise
RP/0/RSP0/CPU0:router(config-ldp-lbl-advt)# for pfx_acl_10 to peer_acl_10
RP/0/RSP0/CPU0:router(config-ldp-lbl-advt)# for pfx_acl_20 to peer_acl_20
  

Note


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


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

RP/0/RSP0/CPU0:router(config-ldp)# label advertise
RP/0/RSP0/CPU0:router(config-ldp-lbl-advt)# interface POS 0/1/0/0

Related Commands

Command

Description

show mpls ldp neighbor

Displays information about LDP neighbors.

show mpls ldp bindings

Displays information about LDP label bindings.

label allocate

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

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

no label allocate

Syntax Description

for

Specifies set of prefixes for which local label needs to be allocated.

prefix-acl

IP access-list name or number. Range is from 1 to 99.

host-routes

Allocates the label for host routes only.

Command Default

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

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

The host-routes keyword was added.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

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

LDP supports IPv4 standard access lists only.

Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router(config)# ipv4 access-list pfx_acl_1
RP/0/RSP0/CPU0:router(config-ipv4-acl)# permit 192.168.1.1
RP/0/RSP0/CPU0:router(config-ipv4-acl)# permit 192.168.2.2
RP/0/RSP0/CPU0:router(config-ipv4-acl)# permit 192.168.3.3
  
RP/0/RSP0/CPU0:router(config-ldp)# label allocate for pfx_acl_1
  

Related Commands

Command

Description

show mpls ldp bindings

Displays information about LDP label bindings.

show mpls ldp forwarding

Displays the contents of the LDP forwarding database.

log graceful-restart

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

log graceful-restart

no log graceful-restart

Syntax Description

This command has no arguments or keywords.

Command Default

No default behavior or values

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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


Note


A logging message is issued upon graceful restart session events.


Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router(config-ldp)# log graceful-restart

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

RP/0/RSP0/CPU0:router: mpls_ldp[340]: %ROUTING-LDP-5-GR : GR session 4.4.4.4:0 (instance 1) disconnected 
  
RP/0/RSP0/CPU0:router: mpls_ldp[340]: %ROUTING-LDP-5-GR : GR session 4.4.4.4:0 (instance 2) reconnected 
  
RP/0/RSP0/CPU0:router: mpls_ldp[340]: %ROUTING-LDP-5-GR : GR session 5.5.5.5:0 (instance 3) timed out
  
RP/0/RSP0/CPU0:router: mpls_ldp[336]: %ROUTING-LDP-5-GR_RESTART_COMPLETE : GR forwarding state hold timer has expired
  

Related Commands

Command

Description

show mpls ldp neighbor

Displays information about LDP neighbors.

show mpls ldp graceful-restart

Displays information about LDP GR sessions.

log neighbor

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

log neighbor

no log neighbor

Syntax Description

This command has no arguments or keywords.

Command Default

No default behavior or values

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

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


Note


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


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

RP/0/RSP0/CPU0:router:10 21:11:32.111:mpls_ldp[113]:%LDP-5-NBR_CHANGE: Nbr 10.44.44.44:0, DOWN

Related Commands

Command

Description

show mpls ldp neighbor

Displays information about LDP neighbors.

log nsr

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

log nsr

no log nsr

Syntax Description

This command has no arguments or keywords.

Command Default

No default behavior or values

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router(config-ldp)# log nsr

log session-protection

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

log session-protection

no log session-protection

Syntax Description

This command has no arguments or keywords.

Command Default

No default behavior or values

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router(config-ldp)# log session-protection


Note


Logging messages are issued when session protection events occur.


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

RP/0/RSP0/CPU0:router:Apr 21 12:15:01.742: mpls_ldp[315]:%ROUTING-LDP-5-SESSION_PROTECTION: Session hold up initiated for peer 4.4.4.4:0
  
RP/0/RSP0/CPU0:router:Apr 21 12:18:04.987: mpls_ldp[315]:%ROUTING-LDP-5-SESSION_PROTECTION: Session recovery succeeded for peer 4.4.4.4:0

Related Commands

Command

Description

show mpls ldp neighbor

Displays information about LDP neighbors.

maximum interfaces (MPLS LDP)

To configure upper limit on maximum number of LDP configured interfaces, use the maximum interfaces command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

maximum interfaces number

no maximum interfaces

Syntax Description

number

Maximum number of LDP configured interfaces. Range is 1 to 250 interfaces .

Command Default

By default, you can enable LDP on up to 100 interfaces.

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 4.0.1

This command was removed.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

The following example shows how to set an upper limit of 150 as maximum number of LDP interfaces, which can be enabled on the box:

RP/0/RSP0/CPU0:router(config-ldp)# maximum interfaces 150

Related Commands

Command

Description

show mpls ldp discovery

Displays LDP discovery information.

show mpls ldp summary

Displays LDP summary information.

mpls ldp

To enter MPLS Label Distribution Protocol (LDP) configuration mode, use the mpls ldp command in global configuration mode.

mpls ldp

Syntax Description

This command has no arguments or keywords.

Command Default

No default behavior or values

Command Modes

Global configuration

Command History

Release

Modification

Release 3.9.0

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

The following example shows how to MPLS LDP configuration mode:

RP/0/RSP0/CPU0:router# configure
RP/0/RSP0/CPU0:router(config)# mpls ldp
RP/0/RSP0/CPU0:router(config-ldp)
  

neighbor password

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

neighbor IP-address password { clear | encrypted } password

no neighbor IP-address password

Syntax Description

IP-address

Neighbor IP address.

clear

Clears the password for the encyrption parameter to specify that an unencrypted password will follow.

encrypted

Specifies that an encrypted password will follow.

password

Clear text or encrypted password string.

Command Default

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

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

To override the default password for a specific neighbor, use the neighbor IP-address password command, where the IP-address argument is the IP address of the neighbor.


Note


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


Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router(config-ldp)# neighbor 10.20.20.20 password clear abc

Related Commands

Command

Description

neighbor targeted

Configures transmission of targeted hellos towards a neighbor.

neighbor password disable

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

neighbor IP-address password disable

Syntax Description

IP-address

Neighbor IP address.

Command Default

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

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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


Note


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


Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router(config-ldp)# neighbor 10.20.20.20 password disable abc
RP/0/RSP0/CPU0:router(config-ldp)#

neighbor targeted

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

neighbor IP address targeted

no neighbor IP address targeted

Syntax Description

IP address

Neighbor IP address.

Command Default

No default behavior or values

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

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

Related Commands

Command

Description

neighbor password

Configures password authentication using MD5.

show mpls ldp neighbor

Displays information about LDP neighbors.

show mpls ldp discovery

Displays information about LDP discovery sources.

nsr (MPLS-LDP)

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

nsr

no nsr

Syntax Description

This command has no arguments or keywords.

Command Default

By default, MPLS LDP NSR is disabled.

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

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

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


Note


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


Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

The following example shows how to enable MPLS LDP NSR:

RP/0/RSP0/CPU0:router# configure
RP/0/RSP0/CPU0:router(config)# mpls ldp
RP/0/RSP0/CPU0:router(config-ldp)# nsr
  

Related Commands

Command

Description

nsr process-failures switchover

Configures switchover as a recovery action for active instances to switch over to a standby RP or a DRP, to maintain NSR. For more information, see Cisco ASR 9000 Series Aggregation Services Router  IP Addresses and Services Command Reference .

show mpls ldp neighbor

Displays standby node specific information.

router-id (MPLS LDP)

To specify the IP address of a preferred interface or a specific IP address as the LDP router ID, use the router-id command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.

router-id IP-address

no router-id

Syntax Description

IP-address

32-bit router ID value specified in four-part, dotted-decimal notation.

Command Default

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

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

The router-id command lets you specify an interface with an IP address to be used as the LDP router ID (which is necessary when an IP address selected as the LDP router ID might not be advertisable by the routing protocol to a neighboring router). In such cases, use the router-id command to select the IP address of the specified loopback interface (if the interface is operational) or a specific IP address.

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

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

Note


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


Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

The following example shows how to specify an IP address as the LDP router ID:

RP/0/RSP0/CPU0:router(config-ldp)#router-id 10.0.0.1

Related Commands

Command

Description

show mpls ldp discovery

Displays the status of the LDP discovery process.

show mpls ldp neighbor

Displays information about LDP neighbors.

show mpls ldp parameters

Displays current LDP parameter settings.

session protection

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

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

no session protection

Syntax Description

duration seconds

(Optional) Specifies the protection duration, that is, the number of seconds that targeted discovery should continue following the loss of link discovery to a neighbor. Range is 30 to 2147483.

infinite

(Optional) Specifies session protection to last forever after loss of link discovery.

for peer-acl

(Optional) Specifies set of LDP peers for which session protection is to be enabled.

Command Default

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

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

LDP supports only IPv4 standard access lists.

Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router(config-ldp)# session protection
  

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

RP/0/RSP0/CPU0:router(config-ldp)# session protection for peer_acl duration 30

Related Commands

Command

Description

show mpls ldp neighbor

Displays information about LDP neighbors.

show mpls ldp backoff

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

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

Syntax Description

location node-id

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

standby

(Optional) Displays standby-node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

The location and standby keywords were added.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

Task ID

Task ID

Operations

mpls-ldp

read

Examples

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

RP/0/RSP0/CPU0:router# show mpls ldp backoff
  
Backoff Time:
  Initial:15 sec, Maximum:120 sec
  
Backoff Table: (2 entries)
  
  LDP Id               Backoff (sec)  Waiting (sec)   
  -------------------- -------------- ----------------
  33.33.33.33:0          15               15
  11.11.11.11:0          30               30
  

This table describes the significant fields shown in the display.



Table 1 show mpls ldp backoff Command Field Descriptions

Field

Description

Backoff Time

Initial and maximum backoff time parameters, in seconds.

Backoff Table

List of discovered LDP neighbors for which session setup is being delayed because of previous failures to establish a session due to incompatible configuration. The backoff table incorporates the following information:
LDP Id

Identifies the LDP neighbors.

Backoff (sec)

Specifies the time that the session setup is delayed.

Waiting (sec)

Specifies an approximate time the session setup has been delayed.

Related Commands

Command

Description

backoff

Configures LDP backoff parameters.

show mpls ldp forwarding

Displays the contents of MPLS forwarding table.

show mpls ldp bindings

Displays the contents of LDP LIB.

show mpls ldp bindings

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

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

Syntax Description

IP-address /prefix

(Optional) Destination prefix/mask length, written in A.B.C.D format.

mask

Network mask, written in A.B.C.D format.

length

Mask length, in bits. Range is 0 to 32.

advertisement-acls

(Optional) Displays the label bindings as applied for (advertisement) outbound label filtering ACLs.

brief

(Optional) Displays all the prefixes in the LDP database.

detail

(Optional) Displays the total counts of advertised-to and remote-binding peers in IP address sort order, with remote bindings in tabular format.

local

(Optional) Displays the local label bindings.

local-label label [to label]

(Optional) Displays entries matching local label values. Add the label to label argument to indicate the label range.

local-only

(Optional) Displays binding matches with a local label only.

neighbor address

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

remote-only

(Optional) Displays bindings matches with a remote label only.

remote-label label [to label]

(Optional) Displays entries matching the label values assigned by a neighbor router. Add the label tolabel argument to indicate the label range. Range is from 0 to 2147483647.

summary

(Optional) Displays a summary of the contents of the Label Information Base (LIB).

location node-id

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

standby

(Optional) Displays standby-node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

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

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

Note


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


Task ID

Task ID

Operations

mpls-ldp

read

Examples

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

RP/0/RSP0/CPU0:router# show mpls ldp bindings
  
     5.41.0.0/16 , rev 4 
          local binding: label:IMP-NULL
          No remote bindings
  5.43.9.98/32 , rev 6 
          local binding: label:IMP-NULL
          No remote bindings
  10.10.2.0/24 , rev 12 
          local binding: label:IMP-NULL
          remote bindings : 
              lsr:10.255.255.255:0, label:16 
              lsr:10.256.256.256:0, label:IMP-NULL 
  10.10.3.0/24 , rev 10 
          local binding: label:IMP-NULL
          remote bindings : 
              lsr:10.255.255.255:0, label:IMP-NULL 
              lsr:10.256.256.256:0, label:22 
  22.22.22.22/32 , rev 14 
          local binding: label:16
          remote bindings : 
              lsr:10.255.255.255:0, label:17 
              lsr:10.256.256.256:0, label:IMP-NULL
  33.33.33.33/32 , rev 2 
          local binding: label:IMP-NULL
          remote bindings : 
              lsr:10.255.255.255:0, label:18 
              lsr:10.256.256.256:0, label:23 
  

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

RP/0/RSP0/CPU0:router# show mpls ldp bindings 150.150.150.150/32 detail
  
  150.150.150.150/32, rev 2
       Local binding: label: IMP-NULL
         Advertised to: (6 peers)
           120.120.120.120:0  130.130.130.130:0  150.150.150.1:0  150.150.150.2:0
           150.150.150.3:0    150.150.150.4:0
       Remote bindings:    (3 peers)
           Peer                Label
  -----------------         --------
         120.120.120.120:0     27018
         130.130.130.130:0     26017
         160.160.160.160:0     27274
  

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

RP/0/RSP0/CPU0:router# show mpls ldp bindings neighbor 10.255.255.255
  
  10.10.2.0/24 , rev 12 
          local binding: label:IMP-NULL
          remote bindings : 
              lsr:10.255.255.255, label:16 
  10.10.3.0/24 , rev 10 
          local binding: label:IMP-NULL
          remote bindings : 
              lsr:10.255.255.255:0, label:IMP-NULL 
  22.22.22.22/32 , rev 14 
          local binding: label:16
          remote bindings : 
              lsr:10.255.255.255:0, label:17 
  33.33.33.33/32 , rev 2 
          local binding: label:IMP-NULL
          remote bindings : 
              lsr:10.255.255.255:0, label:18 
  44.44.44.44/32 , rev 16 
          local binding: label:17
          remote bindings : 
              lsr:10.255.255.255:0, label:IMP-NULL
  

This table describes the significant fields shown in the display.



Table 2 show mpls ldp bindings and show mpls ldp bindings neighbor Command Field Descriptions

Field

Description

a.b.c.d/n

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

rev

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

local binding

Locally assigned label for a prefix.

remote bindings

Outgoing labels for this destination learned from other LSRs.1 Each item in this list identifies the LSR from which the outgoing label was learned and reflects the label associated with that LSR. Each LSR in the transmission path is identified by its LDP identifier.

1 Label switched routers.

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

RP/0/RSP0/CPU0:router# show mpls ldp bindings summary
  
  LIB Summary:
    Total Prefix   : 20 
    Revision No    : Current:34, Advertised:34
    Local Bindings : 14
        NULL    : 10 (implicit:10, explicit:0)
        Non-NULL: 4 (lowest:48, highest:51)
    Remote Bindings: 24
  

This table describes the significant fields shown in the display.



Table 3 show mpls ldp bindings summary Command Field Descriptions

Field

Description

Total Prefix

Number of prefixes (routes) known to LDP LIB. All invalid and timed-out routes display as no-routes.

Revision No

Current revision number of LIB entries as well as the minimum revision number that has been advertised to all peers.

Local Bindings

Total number of local bindings, with information on how many of them are Null, non-null, and lowest/highest label assigned or allocated by LDP.

Remote Bindings

Number of remote bindings.

The following sample output shows the access-list advertisement:

RP/0/RSP0/CPU0:router# show mpls ldp bindings advertisement-acls
  
  Advertisement Spec: 
          Prefix ACL = 'pfx_11'
          Prefix ACL = 'pfx_22'
          Prefix ACL = 'pfx_40_1'; Peer ACL = 'peer_11'
  
  5.41.0.0/16 , rev 82 
  11.11.11.11/32 , rev 69 
          Advert ACL(s): Prefix ACL 'pfx_11' 
  20.20.20.20/32 , rev 83 
  22.22.22.22/32 , rev 78 
          Advert ACL(s): Prefix ACL 'pfx_22' 
  40.1.1.0/24 , rev 79 
          Advert ACL(s): Prefix ACL 'pfx_40_1'; Peer ACL 'peer_11' 
  

This table describes the significant fields shown in the display.



Table 4 show mpls ldp bindings advertisement-acls Command Field Descriptions

Field

Description

Advertisement Spec

Lists all prefix and peer access-lists used as outbound label advertisement control.

Advert ACL(s)

Lists the first matching rule (if any) for the prefix entry for outbound label advertisement control (for prefix-acl).

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

RP/0/RSP0/CPU0:router# show mpls ldp bindings brief
  
  Prefix                Local Advertised Remote Bindings
                        Label (peers)         (peers)
  ------------------ -------- ---------- ---------------
  1.1.2.2/32            -          0           1
  1.2.3.4/32            16010      396         0
  4.4.4.4/32            16004      396         3
  10.0.0.0/24           19226      396         395
  

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

RP/0/RSP0/CPU0:router# show mpls ldp bindings local-only
  
  10.12.32.2/32, rev 4
          Local binding: label: IMP-NULL
          No remote bindings
  

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

RP/0/RSP0/CPU0:router# show mpls ldp bindings remote-only
  
  10.26.4.0/24, rev 0
          No local binding
          Remote bindings: (1 peers)
              Peer                Label   
              -----------------   --------
              10.6.6.6:0          IMP-NULL
  10.43.4.0/24, rev 0
          No local binding
          Remote bindings: (1 peers)
              Peer                Label   
              -----------------   --------
              10.4.4.4:0          IMP-NULL
  10.46.4.0/24, rev 0
          No local binding
          Remote bindings: (2 peers)
              Peer                Label   
              -----------------   --------
              10.4.4.4:0          IMP-NULL
              10.6.6.6:0          IMP-NULL
  

Related Commands

Command

Description

label accept

Configures the LDP remote label acceptance.

label advertise

Configures the LDP local label advertisement control.

show mpls ldp neighbor

Displays information on the LDP neighbors.

show mpls ldp forwarding

Displays the contents of the LDP forwarding database.

show mpls ldp discovery

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

show mpls ldp discovery [ IP-address type interface-path-id | brief | link | targeted | summary ] [detail] [ location node-id | standby ]

Syntax Description

IP-address

(Optional) Neighbor IP address.

type

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

interface-path-id

Physical interface or a virtual interface.

Note   

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

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

brief

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

link

(Optional) Displays link information for LDP discovery.

targeted

(Optional) Displays targeted information for LDP discovery.

summary

(Optional) Displays summarized information for LDP discovery.

detail

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

location node-id

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

standby

(Optional) Displays standby node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

The following items were added:

  • The link keyword was added.
  • The targeted keyword was added.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

Task ID

Task ID

Operations

mpls-ldp

read

Examples

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

RP/0/RSP0/CPU0:router# show mpls ldp discovery
  
  Local LDP Identifier: 10.44.44.44:0
  Discovery Sources:
    Interfaces:
       POS 0/1/0/0 : xmit/recv
        LDP Id: 10.33.33.33:0, Transport address: 10.33.33.33
            Hold time: 15 sec (local:15 sec, peer:15 sec)
  

This table describes the significant fields shown in the display.



Table 5 show mpls ldp discovery Command Field Descriptions

Field

Description

Local LDP Identifier

LDP identifier for the local router. An LDP identifier is a 6-byte construct displayed in the form IP address:number. By convention, the first 4 bytes of the LDP identifier constitute the router ID; integers, starting with 0, constitute the final two bytes of the IP address:number construct.

Interfaces

Interfaces engaged in LDP discovery activity, as follows:
xmit field

Indicates that the interface is transmitting LDP discovery hello packets.

recv field

indicates that the interface is receiving LDP discovery hello packets.

The LDP identifiers indicate the LDP neighbors discovered on the interface.

Transport Address

Address associated with this LDP peer (advertised in hello messages).

LDP Id

LDP identifier of the LDP peer.

Hold time

State of the forwarding hold timer and its current value.

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

RP/0/RSP0/CPU0:router# show mpls ldp discovery summary
  
  LDP Identifier: 139.0.0.1:0
  Interfaces:
    Configured: 2
    Enabled   : 1
  Discovery:
    Hello xmit: 1 (1 link)
    Hello recv: 1 (1 link)

This table describes the significant fields shown in the display.



Table 6 show mpls ldp discovery summary Command Field Descriptions

Field

Description

LDP Identifier

The LDP identifier for the local router.

Interfaces

Summary of interfaces engaged in LDP activity.
Configured

Number of interfaces configured for LDP.

Enabled

Number of interfaces on which LDP is actively enabled and is thus sending LDP hellos. An interface configured for LDP is enabled only if running IP and not in the down state.

Discovery

Summary of LDP discovery process.
Hello xmit

Number of local LDP discovery sources (including link and targeted hellos) emitting LDP hellos.

Hello recv

Number of discovered hello sources via link or targeted hello mechanics.

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

RP/0/RSP0/CPU0:router# show mpls ldp discovery brief
  
  Local LDP Identifier: 150.150.150.150:0
  
  Discovery Source         Peer LDP Id          Holdtime Session
  ------------------------ -------------------- -------- -------
  BE35                     130.130.130.130:0    15       Y
  Gi0/6/0/6                160.160.160.160:0    15       Y
  Gi0/6/2/7.1              174.1.1.2:0          45       Y
  Target: 120.120.120.120  120.120.120.120:0    90       Y
  Target: 150.150.150.1    150.150.150.1:0      120      Y
  

Related Commands

Command

Description

discovery hello

Configures LDP link hello parameters.

discovery targeted-hello

Configures LDP targeted-hello parameters.

neighbor targeted

Configures LDP targeted neighbor.

session protection

Configures LDP session protection.

interface (MPLS LDP)

Configures LDP on an interface.

show mpls ldp neighbor

Displays information about LDP neighbors.

show mpls ldp forwarding

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

show mpls ldp forwarding [ IP -address ] { mask | length } [fast-reroute] [detail] [ next-hop | address IP-address | interfaceinterface-path-id | label label-value | neigbor IP -address | unlabelled ] [ local-label label-value ] [ location node-id | summary | standby ]

Syntax Description

IP-address

(Optional) IP address, specified in four-part, dotted-decimal notation.

mask

Network mask.

length

Mask length, in bits. Range is 0 to 32.

detail

(Optional) Displays detailed information for the LDP timestamp that is used for the routing and forwarding update.

fast-reroute

(Optional) Displays the prefix that is LFA FRR protected in nature.

next-hop

Matches prefixes by next-hop IP address.

local-label label-value

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

neighbor

Matches prefixes with a path through specified LDP neighbor.

unlabelled

Matches prefixes containing unlabelled paths.

location node-id

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

summary

(Optional) Displays the summary information for the LDP forwarding information base (LFIB).

standby

(Optional) Displays standby-node specific information.

Command Default

No default behavior or values

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

The following items were added:

  • The detail keyword.
  • Sample output for the detail keyword.
  • The local-label keyword.
  • The location keyword.
  • The standby keyword.

Release 4.0.1

These items were added:

  • The fast-reroute keyword.
  • The summary keyword.
  • The next-hop keyword.
  • The neighbor keyword.
  • The unlabelled keyword.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

Task ID

Task ID

Operations

mpls-ldp

read

Examples

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

RP/0/RSP0/CPU0:router# show mpls ldp forwarding 
  
  Prefix             Label Label      Outgoing     Next Hop        GR Stale
                     In    Out        Interface
  ------------------ ----- ---------- ------------ --------------- -- -----
  2.2.2.2/32         22    ImpNull    PO0/2/0/1      12.0.0.2        N  N
  3.0.0.1/32         24    20         PO0/2/0/1      12.0.0.2        N  N
  3.0.0.2/32         25    21         PO0/2/0/1      12.0.0.2        N  N
  3.0.0.3/32         26    22         PO0/2/0/1      12.0.0.2        N  N
  4.4.4.4/32         20    ExpNullv4  tt10           4.4.4.4         N  N
  4.4.4.5/32         21    ExpNullv4  tt10           4.4.4.4         N  N
  123.0.0.0/24       23    ImpNull    PO0/2/0/1      12.0.0.2        N  N
  3.3.3.3/32       16000   16001      PO0/2/0/3.1  131.1.1.4         Y  N 
                           16002      PO0/2/0/3.2  131.1.2.4         Y  N 
                           16003      PO0/2/0/3.3  131.1.3.4         N  N  
                           16002      PO0/2/0/1    192.11.1.1 (!)    Y  N 
                           Unlabelled PO0/2/0/2    192.11.2.1 (!)    N  N 

  

Note


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


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

RP/0/RSP0/CPU0:router# show mpls ldp forwarding 1.1.1.1/32 detail
  
  Prefix           Label   Label      Outgoing     Next Hop        GR Stale
                   In      Out        Interface                            
  ---------------- ------- ---------- ------------ --------------- -- -----
  3.3.3.3/32       16000   16001     PO0/2/0/3.1   131.1.1.4         N  N
                           [ Protected; path-id 1 backup-path-id 33; 
                           [peer 13.13.13.1:0 ]
                           16002      PO0/2/0/3.2  131.1.2.4         Y  N 
                           [ Protected; path-id 2 backup-path-id 33; 
                           peer 13.13.13.1:0 ]
                           16003      PO0/2/0/3.3  131.1.3.4         N  N
                           [ Protected; path-id 3 backup-path-id 34;
                           peer 13.13.13.2:0 ]  
                           16002      PO0/2/0/1    192.11.1.1 (!)    Y  N
                           [ Backup; path-id 33; peer 14.14.14.1:0 ] 
                           Unlabelled PO0/2/0/2    192.11.2.1 (!)    N  N
                           [ Backup; path-id 34 ]  
    
  
    Routing update   : Mar 31 13:35:25.348 (00:55:32 ago)
    Forwarding update: Mar 31 13:35:25.349 (00:55:32 ago)
  

Note


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


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

This sample output shows the statistics of protected prefixes and protected paths from the summary keyword:

RP/0/RSP0/CPU0:router# show mpls ldp forwarding summary
Forwarding Server (LSD):
  Connected: Yes
  Forwarding State Holdtime: 360 sec
Forwarding States:
  Interfaces: 10
  Local labels: 8
  Rewrites:
    Prefix:
      Total: 8 (0 with ECMP, 8 FRR protected)
      Labelled:
        Primary pathset : 8 labelled (0 partial), 0 unlabelled
        Backup pathset  : 8 labelled (0 partial), 0 unlabelled
        Complete pathset: 8 labelled (0 partial), 0 unlabelled
    Paths:
      Total: 16 (8 backup, 8 FRR protected)
      Labelled: 16 (8 backup)

This table describes the significant fields shown in the display.



Table 7 show mpls ldp forwarding Command Field Descriptions

Field

Description

Prefix/mask

Prefix on the FEC2 for an MPLS forwarding entry.

Label In

Local label assigned to the prefix/mask.

Label Out

Outgoing label for the prefix/mask.

Outgoing Interface

Outgoing physical interface.

Next Hop

Next Hop address.

GR

Graceful restart status (Y or N).

Stale

Status of the entry, stale or not stale. An entry is marked stale when the next-hop graceful restart neighbor disconnects and is unmarked when neighbor reconnects and refreshes the label.

Chkpt

Status of the entry, checkpointed or not checkpointed.

path-id

Primary Path-id.

Backup-path-id

The backup path-id is the path-id of the path protecting a given primary path. A protecting path can be primary path or a non-primary path.

Peer

Displays next-hop LDP peer's LDP identifier.

Connected

Displays LDP connection state with LSD forwarding server.

Forwarding State Holdtime

Displays time that LDP has registered with LSD server to keep LDP forwarding state intact upon LDP disconnect event.

Interfaces

Number of LDP enabled MPLS interfaces.

Local Labels

Number of LDP allocated local labels from LSD.

Rewrites

Counts of Forwarding rewrites. Displays total number of known IPv4 prefixes alongwith information on number of prefixes with more than one ECMP path. This also displays number of prefixes with LFA-FRR protection. The labelled set prints the counts related to prefixes with none, all, partial labelled paths as shown by unlabeled, labelled, and partial keywords. This information is available for primary, backup, and complete path set.

Paths

Forwarding path counts. Displays count of total number of known forwarding paths, along with number of backup paths and number of FRR protected paths. It also displays the count of labelled paths indicating how many of non-primary paths are labelled.

2 Forwarding Equivalence Class.

Related Commands

Command

Description

graceful-restart (MPLS LDP)

Configures the LDP graceful restart feature.

show mpls ldp bindings

Displays the contents of LDP LIB.

show mpls ldp graceful-restart

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

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

Syntax Description

location node-id

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

standby

(Optional) Displays standby-node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

The location and standby keywords were added.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

Task ID

Task ID

Operations

mpls-ldp

read

Examples

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

RP/0/RSP0/CPU0:router# show mpls ldp graceful-restart
  
    Forwarding State Hold timer : Not Running
    GR Neighbors                : 1
  
     Neighbor ID      Up  Connect Count  Liveness Timer      Recovery Timer    
     ---------------  --  -------------  ------------------  ------------------
     10.0.0.2                Y        1                -                   -          
  

This table describes the significant fields shown in the display.



Table 8 show mpls ldp graceful-restart Command Field Descriptions

Field

Description

Forwarding State Hold timer

State of the hold timer—running or not running.

GR Neighbors

Number of graceful restartable neighbors.

Neighbor ID

Router ID of each neighbor.

Up

Neighbor up or down.

Connect Count

Number of times the same neighbor has reconnected.

Liveness Timer

State of the liveness timer (running or not running) and its expiration time, if running.

Recovery Timer

State of the recovery timer (running or not running) and its expiration time, if running.

Related Commands

Command

Description

graceful-restart (MPLS LDP)

Configures the LDP graceful restart feature.

show mpls ldp neighbor

Displays information about LDP neighbors.

show mpls ldp igp sync

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

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

Syntax Description

interface

(Optional) Displays the interface type.

type

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

interface-path-id

(Optional) Physical interface or a virtual interface.

Note   

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

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

location node-id

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

standby

(Optional) Displays standby-node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

The location and standby keywords were added.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

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

Task ID

Task ID

Operations

mpls-ldp

read

Examples

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

RP/0/RSP0/CPU0:router# show mpls ldp igp sync
  
  GigabitEthernet0/3/0/0:
    Sync status: Ready
    Peers:
      2.2.2.2:0
      3.3.3.3:0 (GR)
    GR-only Reachability:
      4.4.4.4:0 (Chkpt-created)
  
  POS0/2/0/0:
    Sync status: Not ready
                 (Deferred; 24 sec remaining)
  
  POS0/2/0/1:
    Sync status: Not ready
  

This table describes the significant fields shown in the display.



Table 9 show mpls ldp igp sync Command Field Descriptions

Field

Description

Sync status

MPLS LDP convergence status on a given link. Ready indicates that the link is converged and is ready to be used by IGP. Not Ready with Deferred means that the link fulfills LDP IGP synchronization requirements but is deferred by LDP IGP synchronization delay timeout configuration setting. Not Ready means that the link is not ready to be used by IGP.

Peers

List of peers converged on the given link. If the peer session is GR3-enabled, output is tagged as GR. If GR-only reachability is indicated due to a GR neighbor record recovered from checkpoint after local start, then Chkpt-created flag is also set.

GR-only Reachability

List of GR4 peers which are not currently converged on a given link but still in the forwarding state.

3 Graceful Restart.
4 Graceful Restart.

Related Commands

Command

Description

igp sync delay

Configures LDP IGP sync delay timeout.

show mpls ldp interface

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

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

Syntax Description

type

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

interface-path-id

Physical interface or a virtual interface.

Note   

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

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

summary

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

brief

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

detail

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

location node-id

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

standby

(Optional) Displays standby-node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

The location and standby keywords were added.

Release 4.2.0

The detail keyword was added.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Task ID

Task ID

Operations

mpls-ldp

read

Examples

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

RP/0/RSP0/CPU0:router# show mpls ldp interface
  
  Interface GigabitEthernet0/3/0/3
      No LDP config
  Interface POS0/2/0/0
      No LDP config
      Auto-config items:
         ospf/100/0
  Interface POS0/2/0/1
      No LDP config
      Auto-config items:
         ospf/100/0
  Interface POS0/2/0/2
      No LDP config
      Auto-config items:
         ospf/100/0
  Interface POS0/2/0/3
      No LDP config
      Auto-config items:
         ospf/100/0
  

This table describes the significant fields shown in the display.



Table 10 show mpls ldp interface Command Field Descriptions

Field

Description

Auto-config items

Lists IGPs that specify an interface for MPLS LDP auto-configuration:
OSPF

ospf instance area

ISIS

isis instance

The following shows a sample output from the show mpls ldp interface detail command for the mesh groups:

RP/0/RSP0/CPU0:router# show mpls ldp interface detail
  
Interface GigabitEthernet0/2/0/0 (0x20200040)
	Enabled via config: LDP interface
Interface GigabitEthernet0/2/0/1 (0x20200060)
	Disabled via config: IGP Auto-config disable
	  Ignoring: LDP interface
Interface GigabitEthernet0/2/0/2 (0x20200080)
	Disabled via config: IGP Auto-config disable
	  Ignoring: LDP interface
Interface tunnel-te1 (0x200000f0)
	Disabled
Interface tunnel-te100 (0x20000110)
	Enabled via config: TE Mesh-group 123, TE Mesh-group all
Interface tunnel-te101 (0x20000130)
	Enabled via config: TE Mesh-group 123, TE Mesh-group all

  

Related Commands

Command

Description

igp auto-config disable

Disables LDP auto-configuration.

show mpls ldp neighbor

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

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

Syntax Description

IP-address

(Optional) Neighbor IP address.

type

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

interface-path-id

Physical interface or a virtual interface.

Note   

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

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

brief

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

detail

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

gr

(Optional) Displays graceful restartable neighbors.

location node-id

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

non-gr

(Optional) Displays non-graceful restartable neighbors.

sp

(Optional) Displays neighbors with session protection.

standby

(Optional) Displays standby-node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

The following items were added:

  • The location keyword was added.
  • Sample output for the brief keyword was modified to add the NSR and IPv4 Label columns.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

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

Task ID

Task ID

Operations

mpls-ldp

read

Examples

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

RP/0/RSP0/CPU0:router# show mpls ldp neighbor 10.22.22.22
  
  Peer LDP Identifier: 10.22.22.22:0
    TCP connection: 10.22.22.22:646 - 10.33.33.33:65530
    Graceful Restart: No
    State: Oper; Msgs sent/rcvd: 46/43
    Up time: 00:31:21
    LDP Discovery Sources: 
  POS 0/2/0/0
    Addresses bound to this peer:
      10.22.22.22     10.10.2.1      
  

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

RP/0/RSP0/CPU0:router# show mpls ldp neighbor non-gr
  
  Peer LDP Identifier: 10.44.44.44:0
    TCP connection: 10.44.44.44:65535 - 10.33.33.33:646
    Graceful Restart: No
    State: Oper; Msgs sent/rcvd: 49/46
    Up time: 00:33:33
    LDP Discovery Sources: 
      POS 0/1/0/0
    Addresses bound to this peer:
      10.44.44.44     10.10.3.2      
  Peer LDP Identifier: 10.22.22.22:0
    TCP connection: 10.22.22.22:646 - 10.33.33.33:65530
    Graceful Restart: No
    State: Oper; Msgs sent/rcvd: 48/45
    Up time: 00:33:11
    LDP Discovery Sources: 
      POS 0/2/0/0
    Addresses bound to this peer:
      10.22.22.22     10.10.2.1 
  

This table describes the significant fields shown in the display.



Table 11 show mpls ldp neighbor Command Field Descriptions

Field

Description

Peer LDP Identifier

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

TCP connection

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

peer port

local IP address

local port

Graceful Restart

Graceful-restart status (Y or N).

State

State of the LDP session. Generally this is Oper (operational), but transient is another possible state.

Msgs sent/rcvd

Number of LDP messages sent to and received from the session peer. The count includes the transmission and receipt of periodic keepalive messages, which are required for maintenance of the LDP session.

Up time

The length of time that this session has been up for (in hh:mm:ss format).

LDP Discovery Sources

The source(s) of LDP discovery activity leading to the establishment of the LDP session.

Addresses bound to this peer

The known interface addresses of the LDP session peer. These are addresses that might appear as “next hop” addresses in the local routing table. They are used to maintain the LFIB5.

5 LFIB = Label Forwarding Information Base.

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

RP/0/RSP0/CPU0:router# show mpls ldp neighbor brief
  
  Peer               GR  NSR  Up Time     Discovery  Address  IPv4 Label
  -----------------  --  ---  ----------  ---------  -------  ----------
  2.2.2.2:0          N   Y    01:39:50            1        4          19
  3.3.3.3:0          N   N    01:38:04            1        3           5
  

This table describes the significant fields shown in the display.



Table 12 show mpls ldp neighbor brief Command Field Descriptions

Field

Description

Peer

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

GR

Graceful-restart status (Y or N).

Up Time

Time the session has been up (in hh:mm:ss format).

Discovery

Number of LDP discovery sources corresponding to the neighbor.

Address

Number of addresses bound to this peer.

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

RP/0/RSP0/CPU0:router# show mpls ldp neighbor detail
 
  Peer LDP Identifier: 2.2.2.2:0
    TCP connection: 2.2.2.2:11707 - 1.1.1.1:646
    Graceful Restart: No
    Session Holdtime: 180 sec
    State: Oper; Msgs sent/rcvd: 33/29
    Up time: 00:13:37
    LDP Discovery Sources: 
       POS0/2/0/1
      Targeted Hello (1.1.1.1 ->2.2.2.2, active)
    Addresses bound to this peer:
      23.0.0.2 2.0.0.2        123.0.4.2       10.42.37.119    
      10.2.2.2        
    Peer holdtime: 180 sec; KA interval: 60 sec; Peer state: Estab
    Clients: Dir Adj Client
    Inbound label filtering: accept acl 'pfx_acl2'
    Session Protection:
      Enabled, state: Ready
      Duration: 30 seconds
  

This table describes the significant fields shown in the display.



Table 13 show mpls ldp neighbor detail Command Field Descriptions

Field

Description

Peer LDP Identifier

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

TCP connection

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

peer port

local IP address

local port

Graceful Restart

Graceful-restart status (Y or N).

Session Holdtime

Session hold time, in seconds.

State

State of the LDP session (operational or transient).

Msgs sent/rcvd

Number of LDP messages sent to and received from the session peer. The count includes the transmission and receipt of periodic keepalive messages, which are required for maintenance of the LDP session.

Up time

Time the session has been up for (in hh:mm:ss format).

Peer holdtime

Time to keep LDP peer session up without receipt of LDP protocol message from a peer.

Peer state

Peer session state.

Peer holdtime

Time to keep LDP peer session up without receipt of LDP protocol message from a peer.

Clients

LDP (internal) clients requesting session with a neighbor.

Inbound label filtering

LDP neighbor inbound filtering policy.

Session Protection

State of the session protection:
Incomplete

Targeted discovery requested but not yet up.

Ready

Targeted discovery and at least one link hello adjacency to the peer are up.

Protecting

Targeted discovery is up and there is no link hello adjacency to the peer. Targeted discovery is protecting and backing up link discoveries.

Duration

Maximum time to maintain session through targeted discovery upon loss of primary link discovery.

Holdtimer

When in “protecting” state, time to keep LDP peer session up without receipt of LDP protocol message from a peer.

Related Commands

Command

Description

graceful-restart (MPLS LDP)

Configures the LDP graceful restart feature.

label accept

Configures the LDP inbound label filtering feature.

session protection

Configures the LDP session protection feature.

show mpls ldp discovery

Displays the status of the LDP discovery process.

show mpls ldp parameters

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

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

Syntax Description

location node-id

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

standby

(Optional) Displays standby-node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

The location and standby keywords were added.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

Task ID

Task ID

Operations

mpls-ldp

read

network

read

Examples

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

RP/0/RSP0/CPU0:router# show mpls ldp parameters
  
  LDP Parameters:
    Protocol Version: 1
    Router ID: 10.11.11.11
    Null Label: Implicit
    Session:
      Hold time: 180 sec
      Keepalive interval: 60 sec
      Backoff: Initial:15 sec, Maximum:120 sec
    Discovery:
      Link Hellos:     Holdtime:15 sec, Interval:5 sec
      Targeted Hellos: Holdtime:90 sec, Interval:10 sec
                       (Accepting peer ACL 'peer_acl_10')
    Graceful Restart:
      Enabled (Configured)
      Reconnect Timeout:120 sec, Forwarding State Holdtime:180 sec
    Timeouts:
      Binding with no-route: 300 sec
      LDP application recovery (with LSD): 360 sec
    OOR state
      Memory: Normal
  

This table describes the significant fields shown in the display.



Table 14 show mpls ldp parameters Command Field Descriptions

Field

Description

Protocol Version

Version of LDP running on the platform.

Router ID

Currently used router ID.

Null Label

LDP use of implicit-null or explicit-null as label for prefixes where it has to use a null label.

Session Hold time

Time LDP session is to be maintained with an LDP peer without receiving LDP traffic or an LDP keepalive message from the peer.

Session Keepalive interval

Time interval between consecutive transmissions of LDP keepalive messages to an LDP peer.

Session Backoff

Initial maximum backoff time for sessions.

Discovery Link Hellos

Time to remember that a neighbor platform wants an LDP session without receiving an LDP hello message from the neighbor (hold time), and the time interval between the transmission of consecutive LDP hello messages to neighbors (interval).

Discovery Targeted Hellos

Indicates the time:

  • To remember that a neighbor platform wants an LDP session when the neighbor platform is not directly connected to the router or the neighbor platform has not sent an LDP hello message. This intervening interval is known as hold time.
  • Interval between the transmission of consecutive hello messages to a neighbor not directly connected to the router and if targeted hellos are being accepted, displaying peer-acl (if any).

Graceful Restart

Status of graceful-restart status (Y or N).

Timeouts

Various timeouts (of interest) that the LDP is using. One timeout is binding no route, which indicates how long the LDP waits for an invalid route before deleting it. It also shows restart recovery time for LSD and LDP.

OOR state

Out of resource memory state: Normal, Major, or Critical.

Related Commands

Command

Description

backoff

Configures the parameters for the LDP backoff mechanism.

discovery hello

Configures the interval between transmission of LDP discovery messages.

explicit-null

Configures a router to advertise an explicit-null label.

graceful-restart (MPLS LDP)

Configures the LDP graceful restart feature.

holdtime (MPLS LDP)

Configures keepalive message hold time for LDP sessions.

neighbor targeted

Specifies the preferred interface or IP address of a Loopback interface for determining the LDP router ID.

show mpls ldp statistics msg-counters

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

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

Syntax Description

IP-address

(Optional) Neighbor IP address.

location node-id

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

standby

(Optional) Displays standby-node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

The location and standby keywords were added.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

Task ID

Task ID

Operations

mpls-ldp

read

Examples

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

RP/0/RSP0/CPU0:router# show mpls ldp statistics msg-counters
  
  Peer LDP Identifier: 10.33.33.33:0
     Msg Sent: (80)
       Init             : 1
       Address          : 1
       Address_Withdraw : 0
       Label_Mapping    : 5
       Label_Withdraw   : 0
       Label_Release    : 0
       Notification     : 0
       KeepAlive        : 73
  
     Msg Rcvd: (81)
       Init             : 1
       Address          : 1
       Address_Withdraw : 0
       Label_Mapping    : 8
       Label_Withdraw   : 0
       Label_Release    : 0
       Notification     : 0
       KeepAlive        : 71
  

Table 1 describes the significant fields shown in the display.

Table 15 show mpls ldp statistics msg-counters Command Field Descriptions

Field

Description

Peer LDP Identifier

LDP identifier of the neighbor (peer).

Msg Sent

Summary of messages sent to the LDP peer.

Msg Rcvd

Summary of messages received from the LDP peer.

Related Commands

Command

Description

clear mpls ldp msg-counters neighbor

Clears MPLS LDP message counter values.

show mpls ldp bindings

Displays the contents of LDP LIB.

show mpls ldp neighbor

Displays LDP neighbor information.

show mpls ldp summary

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

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

Syntax Description

location node-id

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

standby

(Optional) Displays standby-node-specific information.

Command Default

No default behavior or values

Command Modes

EXEC

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Release 3.9.0

The location and standbykeywords were added.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

Task ID

Task ID

Operations

mpls-ldp

read

Examples

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

RP/0/RSP0/CPU0:router# show mpls ldp summary
  
   Routes    : 4
   Neighbors : 1 (1 GR)
   Hello Adj : 1
   Interfaces: 4 (1 forward reference, 2 LDP configured)
   Addresses : 3
   Clients   : 0
   Servers   :
                   Connected  Registered
                   ---------  ----------
       SysDB           Y          Y
       IM              Y          Y
       IPv4 ARM        Y          -
       LSD             Y          Y
       RIBv4           Y          Y
  

This table describes the significant fields shown in the display.



Table 16 show mpls ldp summary Command Field Descriptions

Field

Description

Routes

Number of known IP routes (prefixes).

Neighbors

Number of LDP neighbors, including targeted and graceful restartable neighbors.

Hello Adj

Number of discovered LDP discovery sources.

Interfaces

Number of known IP interfaces and number of LDP configured interfaces.

LDP is configured on a forward-referenced interface which may not exist or for which no IP address is configured.

Addresses

Number of known local IP addresses.

Clients

Number of external LDP clients. This number is always zero.

Servers

Connection and registration status with servers: SysDB6, IM7, IPv4 ARM8, LSD9, and IPv4 RIBv410.

6 SysDB = System Database.
7 IM = Interface Manager.
8 IPv4 ARM = IPv4 Address Resource Manager.
9 LSD = Label Switching Database.
10 RIBv4 = Routing Information Base.

Related Commands

Command

Description

show mpls ldp bindings

Displays the contents of LDP LIB.

show mpls ldp discovery

Displays the status of the LDP discovery process.

show mpls ldp forwarding

Displays the contents of the LDP forwarding database.

show mpls ldp graceful-restart

Displays the status of the LDP graceful restart.

show mpls ldp parameters

Displays current LDP parameter settings.

signalling dscp (LDP)

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

signalling dscp dscp

no signalling dscp

Syntax Description

dscp

DSCP priority value. Range is 0 to 63.

Command Default

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

Command Modes

MPLS LDP configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

DSCP marking improves signaling setup and teardown times.

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


Note


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


Task ID

Task ID

Operations

mpls-ldp

read, write

Examples

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

RP/0/RSP0/CPU0:router(config-ldp)# signalling dscp 56

snmp-server traps mpls ldp

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

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

Syntax Description

up

Displays the session-up notification.

down

Displays the session-down notification.

threshold

Displays the session-backoff-threshold crossed notification.

Command Default

LDP does not send SNMP traps.

Command Modes

Global configuration

Command History

Release

Modification

Release 3.7.2

This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

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

Session up

Generated when sessions go up.

Session down

Generated when sessions go down.

Threshold

Generated when attempts to establish a session fails. The predefined value is 8.

Task ID

Task ID

Operations

mpls-ldp

read, write

mpls-te

read, write

snmp

read, write

Examples

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

RP/0/RSP0/CPU0:router(config)# snmp-server traps mpls ldp up