MPLS Label Distribution Protocol Commands
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MPLS Label Distribution Protocol Commands
This module describes the commands used to configure Label Distribution Protocol (LDP) in a Multiprotocol Label Switching (MPLS) network.
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 IOS XR MPLS Configuration Guide for the Cisco XR 12000 Series Router.
- backoff
- clear mpls ldp msg-counters neighbor
- clear mpls ldp neighbor
- clear mpls ldp forwarding
- default-route
- discovery hello
- discovery instance-tlv disable
- discovery targeted-hello
- discovery transport-address
- downstream-on-demand
- explicit-null
- graceful-restart (MPLS LDP)
- holdtime (MPLS LDP)
- igp auto-config disable
- igp sync delay
- igp sync delay on-proc-restart
- interface (MPLS LDP)
- label accept
- label advertise
- label allocate
- log graceful-restart
- log neighbor
- log nsr
- log session-protection
- maximum interfaces (MPLS LDP)
- mpls ldp
- neighbor password
- neighbor password disable
- neighbor targeted
- nsr (MPLS-LDP)
- router-id (MPLS LDP)
- session protection
- show mpls ldp backoff
- show mpls ldp bindings
- show mpls ldp discovery
- show mpls ldp forwarding
- show mpls ldp graceful-restart
- show mpls ldp igp sync
- show mpls ldp interface
- show mpls ldp neighbor
- show mpls ldp parameters
- show mpls ldp statistics msg-counters
- show mpls ldp summary
- signalling dscp (LDP)
- snmp-server traps mpls ldp
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.
Syntax Description
initial
Initial backoff delay, in seconds. Range is 5 to 50331.
maximum
Maximum backoff delay, in seconds. Range is 5 to 50331.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
The following example shows how to configure the initial backoff delay to 30 seconds and the maximum backoff delay to 240 seconds:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# mpls ldp RP/0/0/CPU0:router(config-ldp)# backoff 30 240clear 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.
Syntax Description
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
The following example shows how to clear message counters for neighbor 10.20.20.20:
RP/0/0/CPU0:router# clear mpls ldp msg-counters neighbor 10.20.20.20clear mpls ldp neighbor
To force Label Distribution Protocol (LDP) session restart, use the clear mpls ldp neighbor command in EXEC mode.
Syntax Description
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
The following example shows how to force an unconditional LDP session restart:
RP/0/0/CPU0:router# clear mpls ldp neighbor 10.20.20.20clear 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.
Syntax Description
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
This is a sample output from the clear mpls ldp forwarding command:
RP/0/0/CPU0:router# clear mpls ldp forwardingdefault-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.
Command Default
Allocates null (implicit or explicit) local label for IP default route prefix 0.0.0.0/0.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
The following example shows how to enable default MPLS switching for default prefix:
RP/0/0/CPU0:router(config-ldp)# default-routediscovery 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.
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 History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
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 History
Release
Modification
Release 3.2
Support was added for the from acl keyword and argument under the accept command.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
The following example shows how to configure the targeted-hello holdtime to 45 seconds:
RP/0/0/CPU0:router(config-ldp)# discovery targeted-hello holdtime 45The following example shows how to configure the targeted-hello interval to 5 seconds:
RP/0/0/CPU0:router(config-ldp)# discovery targeted-hello interval 5The following example shows how to configure acceptance of targeted hellos from all peers:
RP/0/0/CPU0:router(config-ldp)# discovery targeted-hello acceptThe following example shows how to configure acceptance of targeted hello from peers 10.1.1.1 and 10.2.2.2 only:
RP/0/0/CPU0:router(config)# ipv4 access-list peer_acl_10 RP/0/0/CPU0:router(config-ipv4-acl)# permit 10.1.1.1 RP/0/0/CPU0:router(config-ipv4-acl)# permit 10.2.2.2 RP/0/0/CPU0:router(config-ldp)# discovery targeted-hello accept from peer_acl_10discovery 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 History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
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/0/0/CPU0:router(config-ldp)# interface POS 0/1/0/0 RP/0/0/CPU0:router(config-ldp-if)# discovery transport-address 10.10.3.1 RP/0/0/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 10.44.44.44downstream-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.
Syntax Description
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
Examples
This is a sample output from the downstream-on-demand command:
RP/0/0/CPU0:router(config-ldp)# downstream-on-demand with access-listexplicit-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.
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 History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
The following command shows how to advertise explicit null for all directly connected routes to all LDP peers:
RP/0/0/CPU0:router(config-ldp)# explicit-nullThe 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/0/0/CPU0:router(config)# ipv4 access-list pfx_acl_192_168 RP/0/0/CPU0:router(config-ipv4-acl)# permit 192.168.0.0 RP/0/0/CPU0:router(config-ldp)# explicit-null for pfx_acl_192_168The 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/0/0/CPU0:router(config)# ipv4 access-list peer_acl_10 RP/0/0/CPU0:router(config-ipv4-acl)# permit 10.1.1.1 RP/0/0/CPU0:router(config-ipv4-acl)# permit 10.2.2.2 RP/0/0/CPU0:router(config-ldp)# explicit-null to peer_acl_10The 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/0/0/CPU0:router(config-ldp)# explicit-null for pfx_acl_192_168 to peer_acl_10graceful-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 History
Release
Modification
Release 3.2
This command was supported.
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 the proper task IDs. If you suspect 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
Examples
The following example shows how to configure an existing session for graceful restart:
RP/0/0/CPU0:router(config-ldp)# graceful-restart RP/0/0/CPU0:router:Apr 3 10:56:05.392 : mpls_ldp[336]: %ROUTING-LDP-5-NBR_CHANGE : Nbr 2.2.2.2:0, DOWN RP/0/0/CPU0:router:Apr 3 10:56:05.392 : mpls_ldp[336]: %ROUTING-LDP-5-NBR_CHANGE : Nbr 3.3.3.3:0, DOWN RP/0/0/CPU0:router:Apr 3 10:56:09.525 : mpls_ldp[336]: %ROUTING-LDP-5-NBR_CHANGE : Nbr 3.3.3.3:0, UP RP/0/0/CPU0:router:Apr 3 10:56:11.114 : mpls_ldp[336]: %ROUTING-LDP-5-NBR_CHANGE : Nbr 2.2.2.2:0, UP RP/0/0/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/0/0/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 - -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.
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 History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
Examples
The following example shows how to change the hold time of LDP sessions to 30 seconds:
RP/0/0/CPU0:router(config-ldp)# holdtime 30igp 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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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 IOS XR Routing Configuration Guide for the Cisco XR 12000 Series Router.
Task ID
Examples
The following example shows how to disable LDP auto-configuration on POS 0/1/0/3:
RP/0/0/CPU0:router(config)# mpls ldp RP/0/0/CPU0:router(config-ldp)# interface pos 0/1/0/3 RP/0/0/CPU0:router(config-ldp-if)# igp auto-config disableigp 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.
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 History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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.
Task ID
Examples
The following example shows how to configure LDP to delay declaration of sync-up to 30 seconds:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# mpls ldp RP/0/0/CPU0:router(config-ldp)# igp sync delay 30igp sync delay on-proc-restart
To delay the declaration of synchronization events to the Interior Gateway Protocol (IGP) when the label distribution protocol (LDP) fails or restarts, use the igp sync delay on-proc restart command in MPLS LDP configuration mode. To return to the default behavior, use the no form of this command.
Syntax Description
seconds
Time, in seconds, duration of process-level delay for synchronization events when the LDP fails or restarts. Range is from 60 to 600.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
The igp sync delay on-proc restart command enables a process-level delay for synchronization events when the LDP fails or restarts. This delay defers the sending of sync-up events to the IGP until most or all the LDP sessions converge and also allows the LDP to stabilize. This allows the LDP process failure to be less stressful because IGPs receive all the sync-up events in bulk. This means that the IGP is required to run the shortest path first (SPF) and link-state advertisements (LSAs) only one time with an overall view of the sync-up events.
Task ID
Examples
The following example shows how to configure LDP to delay the declaration of synchronization events to IGP by 60 seconds:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# mpls ldp RP/0/0/CPU0:router(config-ldp)# igp sync delay on-proc restart 60The following example shows the status following execution of the command:
RP/0/0/CPU0:router# show mpls ldp igp sync Process Restart Sync Delay: 60 sec, Gloal timer running (15 sec remaining) GigabitEthernet0/3/0/2: Sync status: Deferred ….When the timer is not running, the output displays the following:
Process Restart Sync Delay: 60 sec, Global timer not runninginterface (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.
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 History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
The following example shows how to configure LDP on POS interface 0/1/0/0:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# mpls ldp RP/0/0/CPU0:router(config-ldp)# interface POS 0/1/0/0 RP/0/0/CPU0:router(config-ldp-if)#The following example shows how to configure LDP on an MPLS TE tunnel:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# mpls ldp RP/0/0/CPU0:router(config-ldp)# interface tunnel-te 123 RP/0/0/CPU0:router(config-ldp-if)#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.
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 History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
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/0/0/CPU0:router(config-ldp)# label accept RP/0/0/CPU0:router(config-ldp-lbl-acpt)# for pfx_acl_1 from 1.1.1.1 RP/0/0/CPU0:router(config-ldp-lbl-acpt)# for pfx_acl_2 from 2.2.2.2 RP/0/0/CPU0:router(config-ldp-lbl-acpt)# for pfx_acl_3 from 3.3.3.3label 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 History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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:
- 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
Examples
The following example shows how to disable advertisement of all locally assigned labels to all peers:
RP/0/0/CPU0:router(config-ldp)# label advertise RP/0/0/CPU0:router(config-ldp-lbl-advt)# disableThe following example shows how to send labels only for prefixes 10.1.1.0 and 20.1.1.0 to all peers:
RP/0/0/CPU0:router(config)# ipv4 access-list pfx_acl_1 RP/0/0/CPU0:router(config-ipv4-acl)# permit 10.1.1.0 RP/0/0/CPU0:router(config-ipv4-acl)# permit 20.1.1.0 RP/0/0/CPU0:router(config-ldp)# label advertise RP/0/0/CPU0:router(config-ldp-lbl-advt)# disable RP/0/0/CPU0:router(config-ldp-lbl-advt)# for pfx_acl_1The 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/0/0/CPU0:router(config)# ipv4 access-list pfx_acl_10 RP/0/0/CPU0:router(config-ipv4-acl)# permit 10.0.0.0 RP/0/0/CPU0:router(config)# ipv4 access-list pfx_acl_20 RP/0/0/CPU0:router(config-ipv4-acl)# permit 20.0.0.0 RP/0/0/CPU0:router(config)# ipv4 access-list peer_acl_10 RP/0/0/CPU0:router(config-ipv4-acl)# permit 10.1.1.1 RP/0/0/CPU0:router(config-ipv4-acl)# permit 10.2.2.2 RP/0/0/CPU0:router(config)# ipv4 access-list peer_acl_20 RP/0/0/CPU0:router(config-ipv4-acl)# permit 20.1.1.1 RP/0/0/CPU0:router(config-ldp)# label advertise RP/0/0/CPU0:router(config-ldp-lbl-advt)# for pfx_acl_10 to peer_acl_10 RP/0/0/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/0/0/CPU0:router(config-ldp)# label advertise RP/0/0/CPU0:router(config-ldp-lbl-advt)# interface POS 0/1/0/0label 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.
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 History
Release
Modification
Release 3.3.0
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 the proper task IDs. If you suspect 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
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/0/0/CPU0:router(config)# ipv4 access-list pfx_acl_1 RP/0/0/CPU0:router(config-ipv4-acl)# permit 192.168.1.1 RP/0/0/CPU0:router(config-ipv4-acl)# permit 192.168.2.2 RP/0/0/CPU0:router(config-ipv4-acl)# permit 192.168.3.3 RP/0/0/CPU0:router(config-ldp)# label allocate for pfx_acl_1log 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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
The following example shows how to enable logging messages for graceful restart session events:
RP/0/0/CPU0:router(config-ldp)# log graceful-restartThe following sample output shows the logging events that can be displayed on the console:
RP/0/0/CPU0:router: mpls_ldp[340]: %ROUTING-LDP-5-GR : GR session 4.4.4.4:0 (instance 1) disconnected RP/0/0/CPU0:router: mpls_ldp[340]: %ROUTING-LDP-5-GR : GR session 4.4.4.4:0 (instance 2) reconnected RP/0/0/CPU0:router: mpls_ldp[340]: %ROUTING-LDP-5-GR : GR session 5.5.5.5:0 (instance 3) timed out RP/0/0/CPU0:router: mpls_ldp[336]: %ROUTING-LDP-5-GR_RESTART_COMPLETE : GR forwarding state hold timer has expiredlog 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.
Command History
Release
Modification
Release 3.2
This command was supported.
Release 3.3.0
The log neighbor command replaced the former log neighbor changes command.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
The following example shows how to enable logging messages for neighbor session up and down events:
RP/0/0/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/0/0/CPU0:router:10 21:11:32.111:mpls_ldp[113]:%LDP-5-NBR_CHANGE: Nbr 10.44.44.44:0, DOWNlog 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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
The following example shows how to enable logging messages for session protection events:
RP/0/0/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/0/0/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/0/0/CPU0:router:Apr 21 12:18:04.987: mpls_ldp[315]:%ROUTING-LDP-5-SESSION_PROTECTION: Session recovery succeeded for peer 4.4.4.4:0maximum 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.
Syntax Description
Command History
Release
Modification
Release 3.3.0
This command was introduced.
Release 3.5.1
Support for this command was removed.
Release 3.8.0
This command was moved to ‘hidden’ status and is no longer valid.
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 the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
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/0/0/CPU0:router(config-ldp)# maximum interfaces 150mpls ldp
To enter MPLS Label Distribution Protocol (LDP) configuration mode, use the mpls ldp command in global configuration mode.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
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.
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 History
Release
Modification
Release 3.2
The command was changed to use clear and encrypted instead of the numbers 0/7 .
Release 3.8.0
The command functionality was modified in the way the neighbor password command was being used for configuring global default passwords.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
The following example shows how to configure the password abc for neighbor 10.20.20.20:
RP/0/0/CPU0:router(config-ldp)# neighbor 10.20.20.20 password clear abcneighbor password disable
To override an individual neighbor which requires no password, use the neighbor password disable command in MPLS LDP configuration mode.
Syntax Description
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
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.
Syntax Description
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
Examples
The following example shows how to set up a targeted discovery session for neighbor 200.1.1.1:
RP/0/RP0/CPU0:router(config-ldp)# neighbor 200.1.1.1 targetednsr (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.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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 processor (RP) or distributed route processor (DRP) failover
- 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
Examples
The following example shows how to enable MPLS LDP NSR:
RP/0/0/CPU0:router# configure RP/0/0/CPU0:router(config)# mpls ldp RP/0/0/CPU0:router(config-ldp)# nsrRelated 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 IOS XRIP Addresses and Services Command Reference for the Cisco XR 12000 Series Router.
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.
Syntax Description
Command Default
LDP uses router ID as determined by global router ID agent, IP Address Repository Manager (IP ARM).
Command History
Release
Modification
Release 3.2
This command was supported.
Release 3.4.0
Deprecated interface keyword.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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:
- Configured LDP router ID.
- Global router ID (if configured).
Calculated (computed) using the primary IPv4 address of the highest numbered configured loopback address. We recommend configuring at least one loopback address.
Note
We recommend that you configure an IP address for the LDP router-id to avoid unnecessary session flaps.
Task ID
Examples
The following example shows how to specify the loopback interface 1 as the preferred interface used to determine the LDP router ID:
RP/0/0/CPU0:router(config-ldp)#router-id loopback 1session 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.
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 History
Release
Modification
Release 3.3.0
This command was introduced.
Release 3.4.0
Default value for duration keyword changed from infinite to 24 hours. The infinite keyword was added for duration value.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
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/0/0/CPU0:router(config-ldp)# session protectionThe 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/0/0/CPU0:router(config-ldp)# session protection for peer_acl duration 30show 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.
Syntax Description
location node-id
(Optional) Displays location information for the specified node ID.
standby
(Optional) Displays standby-node-specific information.
Command History
Release
Modification
Release 3.2
This command was supported.
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 the proper task IDs. If you suspect 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
Examples
The following shows a sample output from the show mpls ldp backoff command:
RP/0/0/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 DescriptionsField
Description
Backoff Time
Initial and maximum backoff time parameters, in seconds.
Backoff Table
- 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.
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 History
Release
Modification
Release 3.2
The advertisement-acls keyword was supported.
Release 3.6.3
The location, standby,remote-only,remote-label, and local-onlykeywords were added.
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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:
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
Examples
The following sample output displays the contents of the LIB for the default routing domain:
RP/0/0/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:23The 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/0/0/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 27274The 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/0/0/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 DescriptionsField
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.
(rewrite)
Binding has been written into MPLS forwarding and is in use.
(no route)
Route is not valid. LDP times it out before the local binding is deleted.
1 Label switched routers.The following sample output summarizes the content by using the summary keyword:
RP/0/0/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 DescriptionsField
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/0/0/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 DescriptionsField
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/0/0/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 395The following sample output shows that the binding matches with a local label:
RP/0/0/CPU0:router# show mpls ldp bindings local-only 10.12.32.2/32, rev 4 Local binding: label: IMP-NULL No remote bindingsThe following sample output shows that the binding matches with a remote label:
RP/0/0/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-NULLshow 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 History
Release
Modification
Release 3.2
This command was supported.
Release 3.3.0
The summary keyword was added.
Release 3.6.3
The following items were added:
Release 3.9.0
The following items were added:
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
The following sample output is from the show mpls ldp discovery command:
RP/0/0/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 DescriptionsField
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
- 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/0/0/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 DescriptionsField
Description
LDP Identifier
The LDP identifier for the local router.
Interfaces
- 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
- 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/0/0/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 Yshow 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 History
Release
Modification
Release 3.2
This command was supported.
Release 3.3.0
Sample output was modified.
Release 3.9.0
The following items were added:
Release 4.0.1
These items were added:
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
Examples
This is a sample output from the show mpls ldp forwarding command:
RP/0/0/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/0/0/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/0/0/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 DescriptionsField
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.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.
Syntax Description
location node-id
(Optional) Displays location information for the specified node ID.
standby
(Optional) Displays standby-node-specific information.
Command History
Release
Modification
Release 3.2
This command was supported.
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 the proper task IDs. If you suspect 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
Examples
The following shows a sample output from theshow mpls ldp graceful-restart command:
RP/0/0/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 DescriptionsField
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.
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.
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 History
Release
Modification
Release 3.3.0
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 the proper task IDs. If you suspect 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
Examples
The following shows a sample output from the show mpls ldp igp synccommand:
RP/0/0/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 DescriptionsField
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.show mpls ldp interface
To display information about LDP-enabled interfaces, use the show mpls ldp interfaces command in EXEC mode.
Syntax Description
type
(Optional) Interface type. For more information, use the question mark (?) online help function.
interface-path-id
Physical interface or a virtual interface.
Note Use the show interfaces command to see a list of all possible interfaces currently configured on the router.
For more information about the syntax for the router, use the question mark (?) online help function.
summary
(Optional) Displays summary information about a specified LDP-enabled interface.
brief
(Optional) Displays concise 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 History
Release
Modification
Release 3.5.0
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 the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.
Task ID
Examples
The following shows a sample output from the show mpls ldp interface command:
RP/0/0/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/100/0show 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 History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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:
Task ID
Examples
The following shows a sample output from the show mpls ldp neighbor command using an IP address:
RP/0/0/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 10.10.2.1The following shows a sample output from the show mpls ldp neighbor command using the non-gr keyword:
RP/0/0/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 DescriptionsField
Description
Peer LDP Identifier
LDP identifier of the neighbor (peer) for this session.
TCP connection
- 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/0/0/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 DescriptionsField
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/0/0/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 DescriptionsField
Description
Peer LDP Identifier
LDP identifier of the neighbor (peer) for this session.
TCP connection
- 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
- 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.
show mpls ldp parameters
Syntax Description
location node-id
(Optional) Displays location information for the specified node ID.
standby
(Optional) Displays standby-node-specific information.
Command History
Release
Modification
Release 3.2
This command was supported.
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 the proper task IDs. If you suspect 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
Examples
The following shows a sample output from the show mpls ldp parameters command:
RP/0/0/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: NormalRelated Commands
Command
Description
Configures the parameters for the LDP backoff mechanism.
Configures the interval between transmission of LDP discovery messages.
Configures a router to advertise an explicit-null label.
Configures the LDP graceful restart feature.
Configures keepalive message hold time for LDP sessions.
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.
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 History
Release
Modification
Release 3.2
This command was supported.
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 the proper task IDs. If you suspect 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
Examples
The following shows a sample output from the show mpls ldp statistics msg-counters command:
RP/0/0/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 : 71Table 1 describes the significant fields shown in the display.
show mpls ldp summary
Syntax Description
location node-id
(Optional) Displays location information for the specified node ID.
standby
(Optional) Displays standby-node-specific information.
Command History
Release
Modification
Release 3.2
This command was supported.
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 the proper task IDs. If you suspect 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
Examples
The following shows a sample output from the show mpls ldp summary command:
RP/0/0/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 DescriptionsField
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.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.
Syntax Description
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
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.
Syntax Description
up
Displays the session-up notification.
down
Displays the session-down notification.
threshold
Displays the session-backoff-threshold crossed notification.
Command History
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect 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
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