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The MPLS Pseudowire Status Signaling feature enables you to configure the router so it can send pseudowire status to a peer router, even when the attachment circuit is down.
Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the "Feature Information for MPLS Pseudowire Status Signaling" section.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
•Prerequisites for MPLS Pseudowire Status Signaling
•Restrictions for MPLS Pseudowire Status Signaling
•Information About MPLS Pseudowire Status Signaling
•How to Configure MPLS Pseudowire Status Signaling
•Configuration Examples for MPLS Pseudowire Status Signaling
•Feature Information for MPLS Pseudowire Status Signaling
•Before configuring this feature, make sure that both peer routers are capable of sending and receiving pseudowire status messages.
•Both peer routers must support the ability to send and receive pseudowire status messages in label advertisement and label notification messages. If both peer routers do not support pseudowire status messages, Cisco recommends that you disable the messages with the no status command.
•This feature is not integrated with Any Transport over MPLS (AToM) Virtual Circuit Connection Verification (VCCV).
•This feature is not integrated with Bidirectional Forwarding Detection (BFD).
•The standby and required switchover values from IETF draft-muley-pwe3-redundancy-02.txt are not supported.
•How MPLS Pseudowire Status Signaling Works
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The pseudowire status messages are sent in label advertisement and label notification messages if the peer also supports the MPLS Pseudowire Status Signaling feature. You can issue the show mpls l2transport vc detail command to show that both the local and remote routers support pseudowire status messages. The following example shows the line of output to look for:
Router# show mpls l2transport vc detail
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.
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status TLV support (local/remote): enabled/supported
The peer routers must support the ability to send and receive pseudowire status messages in label advertisement and label notification messages. If one router does not support pseudowire status messages, Cisco recommends that you disable the messages with the no status command. This returns the router to label withdraw mode.
If the peer does not support the MPLS Pseudowire Status Signaling feature, the local router changes its mode of operation to label withdraw mode. You can issue the show mpls l2transport vc detail command to show that the remote router does not support pseudowire status messages. The following example shows the line of output to look for:
Router# show mpls l2transport vc detail
.
.
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status TLV support (local/remote): enabled/not supported
When you issue the following debug mpls l2transport vc commands, the messages show that the peer router does not supportthe MPLS Pseudowire Status Signaling feature and that the local router is changing to withdraw mode, as shown in bold in the following example:
Router#
debug mpls l2transport vc event
Router# debug mpls l2transport vc status event
Router# debug mpls l2transport vc status fsm
Router# debug mpls l2transport vc ldp
*Feb 26 13:41:40.707: AToM LDP [10.1.1.2]:
Sending label withdraw msg
*Feb 26 13:41:40.707: AToM LDP [10.1.1.2]: VC Type 5, mtu 1500
*Feb 26 13:41:40.707: AToM LDP [10.1.1.2]: VC ID 100, label 18
*Feb 26 13:41:40.707: AToM LDP [10.1.1.2]: Status 0x0000000A [PW Status NOT supported]
When the attachment circuit is down between the two routers, the output of the show mpls l2transport vc detail command shows the following status:
Router# show mpls l2transport vc detail
.
.
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Last remote LDP TLV status rcvd: AC DOWN(rx,tx faults)
The debug messages also indicate that the attachment circuit is down, as shown in bold in the command output:
Router#
debug mpls l2transport vc event
Router# debug mpls l2transport vc status event
Router# debug mpls l2transport vc status fsm
Router# debug mpls l2transport vc ldp
*Feb 26 11:51:42.427: AToM LDP [10.1.1.1]: Received notif msg, id 88
*Feb 26 11:51:42.427: AToM LDP [10.1.1.1]: Status 0x00000007 [PW Status]
*Feb 26 11:51:42.427: AToM LDP [10.1.1.1]: PW Status 0x00000006 [AC DOWN(rx,tx faults)]
Other pseudowire status messages include not-forwarding, pw-tx-fault, and pw-rx-fault.
The debug mpls l2transport vc and the show mpls l2transport vc detail commands show output that contains message codes. For example:
Label/status state machine: established, LruRru
AToM MGR [10.9.9.9, 100]: S:Evt local up, LndRru->LnuRru
The message codes (LruRru, LndRru, and LnuRru) indicate the status of the local and remote routers. You can use the following key to interpret the message codes:
•L—local router
•R—remote router
•r or n—ready (r) or not ready (n)
•u or d—up (u) or down (d) status
The output also includes other values:
•D—Dataplane
•S—Local shutdown
•Enabling MPLS Pseudowire Status Signaling (required)
Perform the following task to enable the router to send pseudowire status to a peer router even when the attachment circuit is down. If both routers do not support pseudowire status messages, then disable the messages with the no status command.
1. enable
2. configure terminal
3. pseudowire-class name
4. status
5. encapsulation mpls
6. exit
7. exit
8. show mpls l2transport vc detail
This section contains the following examples:
•Example: MPLS Pseudowire Status Signaling
•Example: Verifying That Both Routers Support Pseudowire Status Messages
The following example configures the MPLS Pseudowire Status Signaling feature on two PE routers. By default, status messages are enabled. The status command is included in this example in case status messages have been disabled.
PE1
interface Loopback0
ip address 10.1.1.1 255.255.255.255
!
pseudowire-class atomstatus
encapsulation mpls
status
!
interface GigabitEthernet0/0/1
xconnect 10.1.1.2 123 pw-class atomstatus
PE2
interface Loopback0
ip address 10.1.1.2 255.255.255.255
!
pseudowire-class atomstatus
encapsulation mpls
status
!
interface GigabitEthernet3/3/0
xconnect 10.1.1.1 123 pw-class atomstatus
You can issue the show mpls l2transport vc detail command to show that both the local and remote routers support pseudowire status messages. The following example shows the line of output to look for:
Router# show mpls l2transport vc detail
.
.
.
status TLV support (local/remote): enabled/supported
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Cisco IOS commands |
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Description of commands associated with MPLS and MPLS applications |
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Any Transport over MPLS |
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No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature. |
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Table 1 lists the release history for this feature and provides links to specific configuration information.
Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Note Table 1 lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
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MPLS Pseudowire Status Signaling |
Cisco IOS XE Release 2.3 |
The MPLS Pseudowire Status Signaling feature enables you to configure the router so it can send pseudowire status to a peer router, even when the attachment circuit is down. The following sections provide information about this feature: •Information About MPLS Pseudowire Status Signaling •How to Configure MPLS Pseudowire Status Signaling The following commands were introduced or modified: debug mpls l2transport vc, show mpls l2transport vc, status (pseudowire class). |