Published On: August 6ᵗʰ, 2019 02:04

MPLS Layer 2 VPNs Configuration Guide, Cisco IOS XE Release 3S

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.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and 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 table at the end of this module.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/​go/​cfn. An account on Cisco.com is not required.

Prerequisites for MPLS Pseudowire Status Signaling

  • Before configuring this feature, make sure that both peer routers are capable of sending and receiving pseudowire status messages.

Restrictions for MPLS Pseudowire Status Signaling

  • 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.

Information About MPLS Pseudowire Status Signaling

How MPLS Pseudowire Status Switching Works

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 
.
.
.
status TLV support (local/remote): enabled/supported

How MPLS Pseudowire Status Switching Works using the commands associated with the L2VPN Protocol-Based CLIs feature

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 l2vpn atom 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:

Device# show l2vpn atom vc detail 
.
.
.
status TLV support (local/remote): enabled/supported

When One Router Does Not Support MPLS Pseudowire Status Signaling

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 
.
.
.
status TLV support (local/remote): enabled/not supported

When you issue the following debug mpls l2transport vccommands, 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 One Router Does Not Support MPLS Pseudowire Status Signaling using the commands associated with the L2VPN Protocol-Based CLIs feature

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, we recommend 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 l2vpn atom 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:

Device# show l2vpn atom vc detail 
.
.
.
status TLV support (local/remote): enabled/not supported

When you issue the following debug l2vpn atom vc commands, the messages show that the peer router does not support the MPLS Pseudowire Status Signaling feature and that the local router is changing to withdraw mode, as shown in the following example:

Device# debug l2vpn atom vc event
Device# debug l2vpn atom vc status event
Device# debug l2vpn atom vc status fsm
Device# debug l2vpn atom vc ldp
*Feb 26 13:41:40.707: AToM LDP [110.1.1.2]: Sending label withdraw msg
*Feb 26 13:41:40.707: AToM LDP [110.1.1.2]:   VC Type   5, mtu 1500
*Feb 26 13:41:40.707: AToM LDP [110.1.1.2]:   VC ID     100, label 18
*Feb 26 13:41:40.707: AToM LDP [110.1.1.2]:   Status 0x0000000A [PW Status NOT supported]

Status Messages Indicating That the Attachment Circuit Is Down

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 
.
.
.
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.

Status Messages Indicating That the Attachment Circuit Is Down using the commands associated with the L2VPN Protocol-Based CLIs feature

When the attachment circuit is down between the two routers, the output of the show l2vpn atom vc detail command shows the following status:

Device# show l2vpn atom vc detail 
.
.
.
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:

Device# debug l2vpn atom  vc event
Device# debug l2vpn atom  vc status event 
Device# debug l2vpn atom vc status fsm 
Device# debug l2vpn atom 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.

Message Codes in the Pseudowire Status Messages

The debug mpls l2transport vcand 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

Message Codes in the Pseudowire Status Messages using the commands associated with the L2VPN Protocol-Based CLIs feature

The debug l2vpn atom vc and the show l2vpn atom 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

How to Configure MPLS Pseudowire Status Signaling

Enabling MPLS Pseudowire Status Signaling

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.

SUMMARY STEPS

1. enable

2. configure terminal

3. pseudowire-class name

4. status

5. encapsulation mpls

6. exit

7. exit

8. show mpls l2transport vc detail


DETAILED STEPS
  Command or Action Purpose
Step 1 enable


Example:
Router> enable
 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2 configure terminal


Example:
Router# configure terminal
 

Enters global configuration mode.

 
Step 3 pseudowire-class name


Example:
Router(config)# pseudowire-class atom 
 

Establishes a pseudowire class with a name that you specify and enters pseudowire class configuration mode.

 
Step 4 status


Example:
Router(config-pw)# status 
 

(Optional) Enables the router to send pseudowire status messages to the peer router through label advertisement and label notification messages.

Note   

By default, status messages are enabled. This step is included only in case status messages have been disabled.

If you need to disable status messages because both peer routers do not support this functionality, enter the no statuscommand.

 
Step 5 encapsulation mpls


Example:
Router(config-pw)# encapsulation mpls
 

Specifies the tunneling encapsulation.

 
Step 6 exit


Example:
Router(config-pw)# exit
 

Exits pseudowire class configuration mode.

 
Step 7 exit


Example:
Router(config)# exit
 

Exits global configuration mode.

 
Step 8 show mpls l2transport vc detail


Example:
Router# show mpls l2transport vc detail 
 

Validates that pseudowire messages can be sent and received.

 

Enabling MPLS Pseudowire Status Signaling using the commands associated with the L2VPN Protocol-Based CLIs feature

Perform this 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.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface pseudowire number

4. status

5. encapsulation mpls

6. neighbor peer-address vcid-value

7. exit

8. exit

9. show l2vpn atom vc detail


DETAILED STEPS
  Command or Action Purpose
Step 1 enable


Example:
Router> enable
 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2 configure terminal


Example:
Device# configure terminal
 

Enters global configuration mode.

 
Step 3 interface pseudowire number


Example:
Device(config)# interface pseudowire 1 
 

Establishes an interface pseudowire with a value that you specify and enters pseudowire configuration mode.

 
Step 4 status


Example:
Device(config-pw)# status 
 

(Optional) Enables the router to send pseudowire status messages to the peer router through label advertisement and label notification messages.

Note   

By default, status messages are enabled. This step is included only in case status messages have been disabled.

If you need to disable status messages because both peer routers do not support this functionality, enter the no statuscommand.

 
Step 5 encapsulation mpls


Example:
Device(config-pw)# encapsulation mpls
 

Specifies the tunneling encapsulation.

 
Step 6 neighbor peer-address vcid-value


Example:
Device(config-pw)#  neighbor 10.0.0.1 123
 

Specifies the peer IP address and virtual circuit (VC) ID value of a Layer 2 VPN (L2VPN) pseudowire.

 
Step 7 exit


Example:
Device(config-pw)# exit
 

Exits pseudowire class configuration mode.

 
Step 8 exit


Example:
Device(config)# exit
 

Exits global configuration mode.

 
Step 9 show l2vpn atom vc detail


Example:
Device# show l2vpn atom vc detail 
 

Validates that pseudowire messages can be sent and received.

 

Configuration Examples for MPLS Pseudowire Status Signaling

Example MPLS Pseudowire Status Signaling

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

Example MPLS Pseudowire Status Signaling using the commands associated with the L2VPN Protocol-Based CLIs feature

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
!
template type pseudowire atomstatus
 encapsulation mpls
 status
!
interface pseudowire 100
 source template type pseudowire atomstatus
interface GigabitEthernet0/0/1
        service instance 300 ethernet
l2vpn xconnect context con1
 member GigabitEthernet2/1/1 service-instance 300
 member Pseudowire 100

PE2

interface Loopback0
 ip address 10.1.1.2 255.255.255.255
!
template type pseudowire atomstatus
 encapsulation mpls
 status
!
interface Pseudowire 100
 source template type pseudowire atomstatus
interface GigabitEthernet3/3/0
        service instance 300 ethernet
l2vpn xconnect context con1
 member GigabitEthernet2/1/1 service-instance 300
 member Pseudowire 100

Example Verifying That Both Routers Support Pseudowire Status Messages

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

Example Verifying That Both Routers Support Pseudowire Status Messages using the commands associated with the L2VPN Protocol-Based CLIs feature

You can issue the show l2vpn atom 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:

Device# show l2vpn atom vc detail 
.
.
.
status TLV support (local/remote): enabled/supported

Additional References

Related Documents

Related Topic

Document Title

Cisco IOS commands

Cisco IOS Master Commands List, All Releases

Description of commands associated with MPLS and MPLS applications

Cisco IOS Multiprotocol Label Switching Command Reference

Any Transport over MPLS

Any Transport over MPLS

Standards

Standard

Title

draft-ietf-pwe3-control-protocol-15.txt

Pseudowire Setup and Maintenance Using LDP

draft-ietf-pwe3-iana-allocation-08.txt

IANA Allocations for Pseudo Wire Edge to Edge Emulation (PWE3)

draft-martini-pwe3-pw-switching-03.txt

Pseudo Wire Switching

MIBs

MIB

MIBs Link

Pseudowire Emulation Edge-to-Edge MIBs for Ethernet, Frame Relay, and ATM Services

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

http:/​/​www.cisco.com/​go/​mibs

RFCs

RFC

Title

No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature.

--

Technical Assistance

Description

Link

The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password.

http:/​/​www.cisco.com/​cisco/​web/​support/​index.html

Feature Information for

The following table provides release information about the feature or features described in this module. This table 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.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/​go/​cfn. An account on Cisco.com is not required.

Table 1 Feature Information for MPLS Pseudowire Status Signaling

Feature Name

Releases

Feature Information

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 commands were introduced or modified: debug mpls l2transport vc, show mpls l2transport vc, status (pseudowire class).