Contents

L2VPN Multisegment Pseudowires

The L2VPN Multisegment Pseudowires feature enables you to configure two or more Layer 2 pseudowire segments that function as a single pseudowire. Layer 2 Virtual Private Network (L2VPN) multisegment pseudowires span multiple cores or autonomous systems of the same or different carrier networks. L2VPN multisegment pseudowires are also used in L2VPN Virtual Private LAN Services (VPLS) Inter-AS Option B networks.

This document explains Multiprotocol Label Switching (MPLS) Operations, Administration, and Maintenance (OAM) Support for L2VPN Multisegment Pseudowires and the MPLS OAM Support for the L2VPN VPLS Inter-AS Option B feature. These features allow you to use ping mpls and trace mpls commands to ensure pseudowire connectivity.

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 L2VPN Multisegment Pseudowires

Before configuring this feature, see the following documents:

Restrictions for L2VPN Multisegment Pseudowires

  • Only Multiprotocol Label Switching (MPLS) Layer 2 pseudowires are supported.
  • In Cisco IOS Release 12.3(33)SRE, only static configuration of the pseudowires is supported for the L2VPN Multisegment Pseudowires feature.
  • In Cisco IOS Release 15.1(1)S, dynamic configuration of the pseudowires is supported and required for the L2VPN VPLS Inter-AS Option B feature.
  • In Cisco IOS Release 12.3(33)SRE, only pseudowires advertised with forwarding equivalence class (FEC) 128 are supported for the L2VPN Multisegment Pseudowires feature. FEC 129 is not supported.
  • In Cisco IOS Release 15.1(1)S, FEC 129 is supported and used to exchange information about the pseudowires for the L2VPN VPLS Inter-AS Option B feature.
  • The S-PE router is limited to 1600 pseudowires.

Information About L2VPN Multisegment Pseudowires

L2VPN Pseudowire Defined

An L2VPN pseudowire (PW) is a tunnel established between two provider edge (PE) routers across the core carrying the Layer 2 payload encapsulated as MPLS data, as shown in the figure below. This helps carriers migrate from traditional Layer 2 networks such as Frame Relay and ATM to an MPLS core. The PWs between two PE routers are located within the same autonomous system (AS). Routers PE1 and PE2 are called terminating PE routers (T-PEs). Attachment circuits are bounded to the PW on these PE routers.

Figure 1. An L2VPN Pseudowire

L2VPN Multisegment Pseudowire Defined

An L2VPN multisegment pseudowire (MS-PW) is a set of two or more PW segments that function as a single PW, as shown in the figure below. It is also known as switched PW. MS-PWs span multiple cores or autonomous systems of the same or different carrier networks. An L2VPN MS-PW can include up to 254 PW segments.

Figure 2. A Multisegment Pseudowire

The end routers are called terminating PE routers (T-PEs), and the switching routers are called S-PE routers. The S-PE router terminates the tunnels of the preceding and succeeding PW segments in an MS-PW. The S-PE router can switch the control and data planes of the preceding and succeeding PW segments of the MS-PW. An MS-PW is declared to be up when all the single-segment PWs are up. For more information, see the L2VPN Pseudowire Switching document.

With the L2VPN Multisegment Pseudowire feature introduced in Cisco IOS Release 12.2(33)SRE, the pseudowires are created statically, and FEC 128 information is used to exchange the information about each AS.

MPLS OAM Support for Multisegment Pseudowires

You can use the ping mpls and trace mplscommands to verify that all the segments of the MPLS multisegment pseudowire are operating.

You can use the ping mpls command to verify connectivity at the following pseudowire points:

  • From one end of the pseudowire to the other
  • From one of the pseudowires to a specific segment
  • The segment between two adjacent S-PE routers

You can use the trace mplscommand to verify connectivity at the following pseudowire points:

  • From one end of the pseudowire to the other
  • From one of the pseudowires to a specific segment
  • The segment between two adjacent S-PE routers
  • A range of segments

MPLS OAM Support for L2VPN VPLS Inter-AS Option B

The L2VPN VPLS Inter-AS Option B feature introduced in Cisco IOS Release 15.1(1)S uses multisegment pseudowires to connect Autonomous System Border Routers (ASBRs) in different autonomous systems. With this feature, the pseudowires are created dynamically, and FEC 129 information is used to exchange the information about each ASBR.

The differences between static multisegment pseudowires and dynamic multisegment pseudowires are listed in the table below.

Table 1 Comparison of Static and Dynamic Multisegment Pseudowires

Static Multisegment Pseudowires

Dynamic Multisegment Pseudowires

Are statically stitched and dynamically signalled.

Are dynamically stitched and dynamically signalled.

Label Distribution Protocol (LDP) exchanges the type length value (TLV) and FEC 128 information is exchanged between segments.

Border Gateway Protocol (BGP) exchanges the TLV and FEC 129 information is exchanged between ASBRs.

For more information about the L2VPN VPLS Inter-AS Option B feature, see L2VPN VPLS Inter-AS Option B.

How to Configure L2VPN Multisegment Pseudowires

Configuring L2VPN Multisegment Pseudowires

Perform the following steps on the S-PE routers to create L2VPN multisegment pseudowires.

Cisco 7600 Router-Specific Instructions

If the Cisco 7600 router is the penultimate hop router connected to the S-PE or T-PE router, issue the following commands on the S-PE or T-PE routers:

  • mpls ldp explicit-null
  • no mls mpls explicit-null propagate-ttl
SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    mpls label protocol ldp

    4.    mpls ldp router-id interface force

    5.    pseudowire-class name

    6.    encapsulation mpls

    7.    switching tlv

    8.    exit

    9.    l2 vfi name point-to-point

    10.    description string

    11.    neighbor ip-address vcid { encapsulation mpls | pw-class pw-class-name }


DETAILED STEPS
     Command or ActionPurpose
    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 mpls label protocol ldp


    Example:
    Router(config)# mpls label protocol ldp
     

    Configures the use of Label Distribution Protocol (LDP) on all interfaces.

     
    Step 4 mpls ldp router-id interface force


    Example:
    Router(config)# mpls ldp router-id loopback0 force
     

    Specifies the preferred interface for determining the LDP router ID.

     
    Step 5 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 6 encapsulation mpls


    Example:
    Router(config-pw-class)# encapsulation mpls
     

    Specifies the tunneling encapsulation.

    • For MPLS L2VPNs, the encapsulation type is mpls.
     
    Step 7 switching tlv


    Example:
    Router(config-pw-class)# switching tlv
     

    (Optional) Enables the advertisement of the switching point type-length variable (TLV) in the label binding.

    • This command is enabled by default.
     
    Step 8 exit


    Example:
    Router(config-pw-class)# exit
     

    Exits pseudowire class configuration mode.

     
    Step 9 l2 vfi name point-to-point


    Example:
    Router(config)# l2 vfi atomtunnel point-to-point
     

    Creates a point-to-point Layer 2 virtual forwarding interface (VFI) and enters VFI configuration mode.

     
    Step 10 description string


    Example:
    Router(config-vfi)# description segment1
     

    Provides a description of the switching provider edge router for a multisegment pseudowire.

     
    Step 11 neighbor ip-address vcid { encapsulation mpls | pw-class pw-class-name }


    Example:
    Router(config-vfi)# neighbor 10.0.0.1 100 pw-class mpls
     

    Sets up an emulated VC.

    • Specify the IP address and the VC ID of the peer router. Also specify the pseudowire class to use for the emulated VC.
    Note   

    Only two neighborcommands are allowed for each l2 vfi point-to-point command.

     

    Displaying Information About the L2VPN Multisegment Pseudowires

    Perform the following task to display the status of L2VPN multisegment pseudowires.

    SUMMARY STEPS

      1.    show mpls l2transport binding

      2.    show mpls l2transport vc detail


    DETAILED STEPS
      Step 1   show mpls l2transport binding

      Use the show mpls l2transport binding command to display information about the pseudowire switching point, as shown in bold in the output. (In the following examples PE1 and PE4 are the T-PE routers.)



      Example:
      Router# show mpls l2transport binding
 
  Destination Address: 10.1.1.1,  VC ID: 102
    Local Label:  17
        Cbit: 1,    VC Type: Ethernet,    GroupID: 0
        MTU: 1500,   Interface Desc: n/a
        VCCV: CC Type: CW [1], RA [2], TTL [3]
              CV Type: LSPV [2]
    Remote Label: 16
        Cbit: 1,    VC Type: Ethernet,    GroupID: 0
        MTU: 1500,   Interface Desc: n/a
        VCCV: CC Type: CW [1], RA [2], TTL [3]
              CV Type: LSPV [2]
        PW Switching Point:
             Vcid   local IP addr      remote IP addr      Description
             101        10.11.11.11    10.20.20.20         PW Switching Point PE3
             100        10.20.20.20    10.11.11.11            PW Switching Point PE2

      Step 2   show mpls l2transport vc detail

      Use the show mpls l2transport vc detail command to display status of the pseudowire switching point. In the following example, the output (shown in bold) displays the segment that is the source of the fault of the multisegment pseudowire:



      Example:
      Router# show mpls l2transport vc detail
Local interface: Se3/0 up, line protocol up, HDLC up
  Destination address: 12.1.1.1, VC ID: 100, VC status: down
    Output interface: Se2/0, imposed label stack {23}
    Preferred path: not configured  
    Default path: active
    Next hop: point2point
  Create time: 00:03:02, last status change time: 00:01:41
  Signaling protocol: LDP, peer 10.1.1.1:0 up
    Targeted Hello: 10.1.1.4(LDP Id) -> 10.1.1.1, LDP is UP
    Status TLV support (local/remote)   : enabled/supported
      LDP route watch                   : enabled
      Label/status state machine        : established, LruRrd
      Last local dataplane   status rcvd: No fault
      Last local SSS circuit status rcvd: No fault
      Last local SSS circuit status sent: DOWN(PW-tx-fault)
      Last local  LDP TLV    status sent: No fault
      Last remote LDP TLV    status rcvd: DOWN(PW-tx-fault)
       PW Switching Point:
       Fault type  Vcid   local IP addr   remote IP addr   Description
       PW-tx-fault  101   10.1.1.1        10.1.1.1         S-PE2
      Last remote LDP ADJ    status rcvd: No fault
    MPLS VC labels: local 19, remote 23 
    Group ID: local 0, remote 0
    MTU: local 1500, remote 1500
    Remote interface description: 
  Sequencing: receive disabled, send disabled
  VC statistics:
    packet totals: receive 16, send 27
    byte totals:   receive 2506, send 3098
    packet drops:  receive 0, seq error 0, send 0

      Verifying Multisegment Pseudowires with ping mpls and trace mpls Commands

      You can use ping mpls and trace mpls commands to verify connectivity in multisegment pseudowires.


      Note

      Some ping mpls and trace mplskeywords that are available with IPv4 LDP or traffic engineering (TE) are not available with pseudowire.

      The following keywords are not available with the ping mpls pseudowire command:

      • dsmap
      • flags
      • force-explicit-null
      • output
      • revision
      • ttl

      The following keywords are not available with the trace mpls pseudowire command:

      • flags
      • force-explicit-null
      • output
      • revision
      • ttl
      >
      SUMMARY STEPS

        1.    ping mpls pseudowire destination-address vc-id [segment segment-number]

        2.    trace mpls pseudowire destination-address vc-id segment segment-number [segment-number ]


      DETAILED STEPS
        Step 1   ping mpls pseudowire destination-address vc-id [segment segment-number]

        Where:

        • destination-address is the address of the S-PE router, which is the end of the segment from the direction of the source.
        • vc-id is the VC ID of the segment from the source to the next PE router.
        • segment segment-number is optional and specifies the segment you want to ping.

        The following examples use the topology shown in the second figure above:

        • To perform an end-to-end ping operation from T-PE1 to T-PE2, enter the following command. destination-address is S-PE1 and vc-idis the VC between T-PE1 and S-PE1.

        ping mpls pseudowire destination-address vc-id

        • To perform a ping operation from T-PE1 to segment 2, enter the following command. destination-address is S-PE1 and vc-idis the VC between T-PE1 and S-PE1.

        ping mpls pseudowire destination-address vc-id segment 2



        Example:
        
 
		  
        

        

        Step 2  
              
			  
				trace 
				mpls 
				pseudowire 
			  
			  
				destination-address 
				vc-id 
			  
			  
				segment 
			  
			  
				segment-number 
			  [segment-number 
			 ]
		  
          
			 
         Where: 
			 
        
 
			 
        •  
				   
					 destination-address 
				   
				   
					  
					  
					 is 
					 the 
					 address 
					 of 
					 the 
					 next 
					 S-PE 
					 router 
					 from 
					 the 
					 origin 
					 of 
					 the 
					 trace. 
				   
				

          • 

        •  
				   
					 vc-id 
				   is the VC ID of the segment from which the 
				  trace command is issued.
				

          • 

        •  
				   
					 segment-number 
				   indicates the segment upon which the trace operation will act. If you enter two segment numbers, the traceroute operation will perform a trace on that range of routers. 
				

          • 

        
 
			 
         The following examples use the topology shown in the second figure above:
			 
        
 
			 
        •  To perform a trace operation from T-PE1 to segment 2 of the multisegment pseudowire, enter the following command. 
				  destination-address is S-PE1 and 
				  vc-idis the VC between T-PE1 and S-PE1.
				

          • 

        
 
			 
         
				 
				  trace 
				  mpls 
				  pseudowire 
				 
				 
				  destination-address 
				  vc-id 
				 
				 
				  segment 
				  2 
				 
			 
        
 
			 
         This example performs a trace from T-PE1 to S-PE2.
			 
        
 
			 
        •  To perform a trace operation on a range of segments, enter the following command. This example performs a trace from S-PE2 to T-PE2. 
				  destination-address is S-PE1 and 
				  vc-id 
				  is the VC between T-PE1 and S-PE1.
				

          • 

        
 
			 
         
				 
				  trace 
				  mpls 
				  pseudowire 
				 
				 
				  destination-address 
				  vc-id 
				 
				 
				   
				   
				  segment 
				  2 
				  4 
				 
			 
        
 
			 
         The following commands perform trace operations on S-PE router 10.10.10.9, first on segment 1, then on segment 2.
			 
        
 
			 
         Segment 1 trace: 
			 
        
 
		   

        Example:
         
			 
        Router# trace mpls pseudowire 10.10.10.9 220 segment 1
Tracing MS-PW segments within range [1-1] peer address 10.10.10.9 and timeout 2 seconds
Codes: '!' - success, 'Q' - request not sent, '.' - timeout,
  'L' - labeled output interface, 'B' - unlabeled output interface,
  'D' - DS Map mismatch, 'F' - no FEC mapping, 'f' - FEC mismatch,
  'M' - malformed request, 'm' - unsupported tlvs, 'N' - no label entry,
  'P' - no rx intf label prot, 'p' - premature termination of LSP,
  'R' - transit router, 'I' - unknown upstream index,
  'X' - unknown return code, 'x' - return code 0
Type escape sequence to abort.
L 1 10.10.9.9 0 ms [Labels: 18 Exp: 0]
    local 10.10.10.22 remote 10.10.10.9 vc id 220
Segment 2 trace:
Router# trace mpls pseudowire 10.10.10.9 220 segment 2
Tracing MS-PW segments within range [1-2] peer address 10.10.10.9 and timeout 2 seconds
Codes: '!' - success, 'Q' - request not sent, '.' - timeout,
  'L' - labeled output interface, 'B' - unlabeled output interface,
  'D' - DS Map mismatch, 'F' - no FEC mapping, 'f' - FEC mismatch,
  'M' - malformed request, 'm' - unsupported tlvs, 'N' - no label entry,
  'P' - no rx intf label prot, 'p' - premature termination of LSP,
  'R' - transit router, 'I' - unknown upstream index,
  'X' - unknown return code, 'x' - return code 0
Type escape sequence to abort.
L 1 10.10.9.9 4 ms [Labels: 18 Exp: 0]
    local 10.10.10.22 remote 10.10.10.9 vc id 220
! 2 10.10.3.3 4 ms [Labels: 16 Exp: 0]
    local 10.10.10.9 remote 10.10.10.3 vc id 220
        
 
		  
        

        

        

        

        

        Verifying L2VPN VPLS Inter-AS Option B with ping mpls and trace mpls Commands
        

         
		
         You can use 
			 ping 
			 mplsand 
		  trace 
			 mpls commands to verify connectivity in configurations using the L2VPN VPLS Inter-AS Option B feature. For end-to-end ping and trace operations, you enter the destination address of the T-PE router at the other end of the pseudowire.
		
        
 
		

        Note
         
		  
         Some 
			 ping 
				mplsand 
			 trace 
				mplskeywords that are available with IPv4 LDP or traffic engineering (TE) are not available with pseudowire.
		  
        
 
		  
         The following keywords are not available with the 
			 ping 
				mpls 
			  
			 pseudowire 
			 command:
		  
        
 
		  
        •  
				 
				  dsmap 
				 
			 

          • 

        •  
				 
				  flags 
				 
			 

          • 

        •  
				 
				  force-explicit-null 
				 
			 

          • 

        •  
				 
				  output 
				 
			 

          • 

        •  
				 
				  revision 
				 
			 

          • 

        •  
				 
				  ttl 
				 
			 

          • 

        
 
		  
         The following keywords are not available with the 
			 trace 
				mpls 
			  
			 pseudowire 
			 command:
		  
        
 
		  
        •  
				 
				  flags 
				 
			 

          • 

        •  
				 
				  force-explicit-null 
				 
			 

          • 

        •  
				 
				  output 
				 
			 

          • 

        •  
				 
				  revision 
				 
			 

          • 

        •  
				 
				  ttl 
				 
			 

          • 

        
 >
		
        
 
	 
        
SUMMARY STEPS
          1.   
       
			  
				ping 
				mpls 
				pseudowire 
			  
			  
				destination-address 
				vc-id 
			  [segment 
			 segment-number]
		  
          

          2.   
       
			  
				trace 
				mpls 
				pseudowire 
			  
			  
				destination-address 
				vc-id 
			  
			  
				segment 
			  
			  
				segment-number 
			  [segment-number 
			 ]
		  
          


        DETAILED STEPS
          Step 1  
              
			  
				ping 
				mpls 
				pseudowire 
			  
			  
				destination-address 
				vc-id 
			  [segment 
			 segment-number]
		  
            
			 
           Where:
			 
          
 
			 
          •  
				   
					 destination-address 
				  is the address of the T-PE2 router at the other end of the pseudowire. 
				

            • 

          •  
				   
					 vc-id 
				   is the VC ID between T-PE1 and S-PE1.
				

            • 

          •  
				   
					 segment 
				   
				   
					 segment-number 
				   
				   
					  
					  
					 is 
					 optional 
					 and 
					 specifies 
					 the 
					 segment 
					 you 
					 want 
					 to 
					 ping. 
				   
				

            • 

          
 
			 
           The following examples use the topology shown in the second figure above:
			 
          
 
			 
          •  To perform an end-to-end ping operation from T-PE1 to T-PE2, enter the following command. destination-address is T-PE2 and 
				  vc-idis the VC between T-PE1 and S-PE1.
				

            • 

          
 
			 
           
				 
				  ping 
				  mpls 
				  pseudowire 
				 
				 
				  destination-address 
				  vc-id 
				 
			 
          
 
		   

          Example:
           
			 
          
 
		  
          

          

          Step 2  
              
			  
				trace 
				mpls 
				pseudowire 
			  
			  
				destination-address 
				vc-id 
			  
			  
				segment 
			  
			  
				segment-number 
			  [segment-number 
			 ]
		  
            
			 
           Where: 
			 
          
 
			 
          •  
				   
					 destination-address 
				  is the address of the T-PE2 router at the other end of the pseudowire.
				

            • 

          •  
				   
					 vc-id 
				   is the VC ID between T-PE1 and S-PE1.
				

            • 

          •  
				   
					 segment-number 
				   indicates the segment upon which the trace operation will act. If you enter two segment numbers, the traceroute operation will perform a trace on that range of routers. 
				

            • 

          
 
			 
           The following examples use the topology shown in the second figure above:
			 
          
 
			 
          •  To perform a trace operation from T-PE1 to T-PE2, enter the following command. 
				  destination-addressis T-PE2 and 
				  vc-idis the VC between T-PE1 and S-PE1.
				

            • 

          
 
			 
           
				 
				  trace 
				  mpls 
				  pseudowire 
				 
				 
				  destination-address 
				  vc-id 
				 
				 
				  segment 
				 
				 
				  2 
				 
			 
          
 
			 
           This example performs a trace from T-PE1 to T-PE2.
			 
          
 
			 
          •  To perform a trace operation on a range of segments, enter the following command. This example performs a trace from S-PE2 to T-PE2. 
				  destination-addressis S-PE1 and 
				  vc-id 
				  is the VC between T-PE1 and S-PE1.
				

            • 

          
 
			 
           
				 
				  trace 
				  mpls 
				  pseudowire 
				 
				 
				  destination-address 
				  vc-id 
				 
				 
				  segment 
				  2 
				  4 
				 
			 
          
 
		  
          

          

          

          

          

          Configuration Examples for L2VPN Multisegment Pseudowires
          

          

          Example  Configuring an L2VPN Multisegment Pseudowire
          

          
      
          
The following example does not include all the commands. Unconfigured interfaces are not shown. Portions of the example relevant to L2VPN Multisegment Pseudowires are shown in bold. 
          

    
          

          T-PE1 Configuration
          
      
      
          no ipv6 cef
multilink bundle-name authenticated
frame-relay switching
mpls traffic-eng tunnels
mpls ldp discovery targeted-hello accept
no mpls ip propagate-ttl forwarded
mpls label protocol ldp
!
policy-map exp2
!
interface Loopback0
 ip address 10.131.191.252 255.255.255.255
 no clns route-cache
!         
interface Ethernet0/0
 ip address 10.131.191.230 255.255.255.252
 mpls label protocol ldp
 mpls ip
 no clns route-cache
 ip rsvp bandwidth 1500 1500
 ip rsvp signalling dscp 0
!
interface Ethernet1/0
 ip address 10.131.159.246 255.255.255.252
shutdown 
 no clns route-cache
!
interface Ethernet2/0
 no ip address
 no cdp enable
!
interface Ethernet2/0.1
 encapsulation dot1Q 1000
 xconnect 10.131.191.251 333 encapsulation mpls
!
router ospf 1
 log-adjacency-changes
 passive-interface Loopback0
 network 10.131.159.244 0.0.0.3 area 0
 network 10.131.191.228 0.0.0.3 area 0
 network 10.131.191.232 0.0.0.3 area 0
 network 10.131.191.252 0.0.0.0 area 0
 network 11.0.0.0 0.0.0.3 area 0
 mpls traffic-eng router-id Loopback0
 mpls traffic-eng area 0
!
ip classless
!
no ip http server
!
mpls ldp router-id Loopback0 force
end
          

    
          

          S-PE1 Configuration
          
      
      
          no ipv6 cef
multilink bundle-name authenticated
mpls traffic-eng tunnels
no mpls traffic-eng auto-bw timers
mpls ldp discovery targeted-hello accept
no mpls ip propagate-ttl forwarded
mpls label protocol ldp
!
policy-map exp2
!
l2 vfi sam-sp point-to-point
 neighbor 10.131.191.252 333 encapsulation mpls
 neighbor 10.131.159.251 222 encapsulation mpls
!         
interface Tunnel3
 ip unnumbered Loopback0
 shutdown
 mpls label protocol ldp
 mpls accounting experimental input
 mpls ip
 tunnel mode mpls traffic-eng
 tunnel destination 10.131.159.252
 tunnel mpls traffic-eng autoroute announce
 tunnel mpls traffic-eng priority 2 2
 tunnel mpls traffic-eng bandwidth 512
 tunnel mpls traffic-eng path-option 1 dynamic
 no clns route-cache
 service-policy output exp2
!
interface Loopback0
 ip address 10.131.191.251 255.255.255.255
 no clns route-cache
!
interface Ethernet0/0
 ip address 10.131.191.229 255.255.255.252
 mpls traffic-eng tunnels
 mpls label protocol ldp
 mpls ip
 no clns route-cache
 ip rsvp bandwidth 1500 1500
 ip rsvp signalling dscp 0
!
interface Ethernet1/0
 ip address 10.131.159.226 255.255.255.252
 mpls traffic-eng tunnels
 mpls ip
 no clns route-cache
service-policy output exp2
 ip rsvp bandwidth 1500 1500
 ip rsvp signalling dscp 0
!
interface Serial2/0
 ip unnumbered Loopback0
 mpls ip
 no fair-queue
 no keepalive
 serial restart-delay 0
 no clns route-cache
!         
router ospf 1
 log-adjacency-changes
 passive-interface Loopback0
 network 10.131.159.224 0.0.0.3 area 0
 network 10.131.191.228 0.0.0.3 area 0
 network 10.131.191.251 0.0.0.0 area 0
 mpls traffic-eng router-id Loopback0
 mpls traffic-eng area 0
!
ip classless
!         
end
          

    
          

          T-PE2 Configuration
          
      
      
          no ipv6 cef
no l2tp congestion-control
multilink bundle-name authenticated
frame-relay switching
mpls traffic-eng tunnels
no mpls traffic-eng auto-bw timers frequency 0
mpls ldp discovery targeted-hello accept
no mpls ip propagate-ttl forwarded
mpls label protocol ldp
!
interface Loopback0
 ip address 10.131.159.252 255.255.255.255
 no clns route-cache
!
interface Ethernet0/0
 ip address 10.131.159.230 255.255.255.252
interface Ethernet0/0
 ip address 10.131.159.230 255.255.255.252
 mpls traffic-eng tunnels
 mpls ip
 no clns route-cache
 ip rsvp bandwidth 1500 1500
 ip rsvp signalling dscp 0
!
interface Ethernet1/0
 ip address 10.131.159.245 255.255.255.252
 shutdown
 mpls ip
 no clns route-cache
!
interface Ethernet3/0.1
 encapsulation dot1Q 1000
 xconnect 10.131.159.251 111 encapsulation mpls
!
router ospf 1
 log-adjacency-changes
 passive-interface Loopback0
 network 10.131.122.0 0.0.0.3 area 0
 network 10.131.159.228 0.0.0.3 area 0
 network 10.131.159.232 0.0.0.3 area 0
 network 10.131.159.244 0.0.0.3 area 0
 network 10.131.159.252 0.0.0.0 area 0
 network 11.0.0.0 0.0.0.3 area 0
 network 19.0.0.0 0.0.0.255 area 0
 mpls traffic-eng router-id Loopback0
 mpls traffic-eng area 0
end
          

    
          

          S-PE2 configuration
          
      
      
          no ipv6 cef
no l2tp congestion-control
multilink bundle-name authenticated
mpls traffic-eng tunnels
no mpls traffic-eng auto-bw timers frequency 0
mpls ldp discovery targeted-hello accept
no mpls ip propagate-ttl forwarded
mpls label protocol ldp
!
l2 vfi sam-sp point-to-point
 neighbor 10.131.159.252 111 encapsulation mpls
 neighbor 10.131.191.251 222 encapsulation mpls
!
!
interface Loopback0
 ip address 10.131.159.251 255.255.255.255
!
interface Ethernet0/0
interface Ethernet0/0
 ip address 10.131.159.229 255.255.255.252
 mpls traffic-eng tunnels
 mpls accounting experimental input
 mpls ip
 ip rsvp bandwidth 1500 1500
 ip rsvp signalling dscp 0
!
interface Ethernet1/0
 ip address 10.131.159.225 255.255.255.252
 mpls traffic-eng tunnels
 mpls ip
 ip rsvp bandwidth 1500 1500
 ip rsvp signalling dscp 0
!
router ospf 1
 log-adjacency-changes
 passive-interface Loopback0
 network 10.131.159.224 0.0.0.3 area 0
 network 10.131.159.228 0.0.0.3 area 0
 network 10.131.159.251 0.0.0.0 area 0
 network 19.0.0.0 0.0.0.255 area 0
 mpls traffic-eng router-id Loopback0
 mpls traffic-eng area 0
!
end
          

    
          

          

          

          

          Additional References
          

           
	 
          

          Related Documents
           
		 
		

           
					 
           Related Topic
					 
          
 
				            		
 
					 
           Document Title
					 
          
 
				            		

          
          

           
					 
           Cisco IOS commands
					 
          
 
				            		
 
					 
           
						Cisco IOS Master Commands List, All Releases 
					 
          
 
				            		

          

           
					 
           MPLS commands
					 
          
 
				            		
 
					 
           
						Cisco IOS Multiprotocol Label Switching Command Reference 
					 
          
 
				            		

          

           
					 
           Layer 2 VPNS
					 
          
 
				            		

           
					 
          •  Any Transport over MPLS 
						

            • 

          •  L2VPN Pseudowire Switching 
						

            • 

          •  MPLS LSP Ping/Traceroute for LDP/TE, and LSP Ping for VCCV 
						

            • 

          
 
				  
          
          		

          

           
					 
           L2VPN VPLS Inter-AS Option B
					 
          
 
				            		
 
					 
           L2VPN VPLS Inter-AS Option B 
					 
          
 
				            		

          
          

          

          
 
	 
          

          Standards
           
		 
		

           
					 
           Standard
					 
          
 
				            		
 
					 
           Title
					 
          
 
				            		

          
          

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

          
          

          

          
 
	 
          

          MIBs
           
		 
		

           
					 
           MIB
					 
          
 
				            		
 
					 
           MIBs Link
					 
          
 
				            		

          
          

           
					 
           No new or modified MIBs are supported by this feature, and support for existing MIBs has not been modified by this feature.
					 
          
 
				            		
 
					 
           To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:
					 
          
 
					 
           
						http:/​/​www.cisco.com/​go/​mibs 
					 
          
 
				            		

          
          

          

          
 
	 
          

          RFCs
           
		 
		

           
					 
           RFC
					 
          
 
				            		
 
					 
           Title
					 
          
 
				            		

          
          

           
					 
           RFC 4379
					 
          
 
				            		
 
					 
           
						http:/​/​tools.ietf.org/​html/​rfc4379 Detecting Multi-Protocol Label Switched (MPLS) Data Plane Failures 
					 
          
 
				            		

          

           
					 
           RFC 4447
					 
          
 
				            		
 
					 
           
						Pseudowire Setup and Maintenance Using the Label Distribution Protocol (LDP) 
					 
          
 
				            		

          

           
					 
           RFC 5085
					 
          
 
				            		
 
					 
           
						Pseudowire Virtual Circuit Connectivity Verification (VCCV) 
					 
          
 
				            		

          
          

          

          
 
	 
          

          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 L2VPN Multisegment Pseudowires
          

           
		
          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 2 Feature Information for L2VPN Multisegment Pseudowires 
           
				  
           Feature Name
				  
          
 
				          		
 
				  
           Releases
				  
          
 
				          		
 
				  
           Feature Information
				  
          
 
				          		

          
          

           
				  
           L2VPN Multisegment Pseudowires 
				  
          
 
				          		
 
				  
           12.2(33)SRE
				  
          
 
				          		
 
				  
           This feature enables you to configure two or more Layer 2 pseudowire segments that function as a single pseudowire. The feature spans multiple cores or autonomous systems of the same or different carrier networks. 
				  
          
 
				          		

          

           
				  
           MPLS OAM Support for Multisegment Pseudowires
				  
          
 
				          		
 
				  
           12.2(33)SRE
				  
          
 
				          		
 
				  
           This feature enables you to use the 
					 ping 
					 mpls and 
						trace 
						mplscommands to verify that all the segments of the MPLS multisegment pseudowire are operating. 
				  
          
 
				          		

          

           
				  
           MPLS OAM Support for L2VPN VPLS Inter-AS Option B
				  
          
 
				          		
 
				  
           15.1(1)S
				  
          
 
				          		
 
				  
           This feature is an enhancement to the MPLS OAM Support for Multisegment Pseudowires feature. This feature allows you to use the 
					 ping 
					 mpls and 
						trace 
						mplscommands to verify the pseudowire used in a L2VPN VPLS Inter-AS Option B configuration. 
				  
          
 
				          		

          
          

          

          
 
		
           
		
          
 
	 
          

          

          

          


          













L2VPN Multisegment Pseudowires

                              

          


          Contents
          L2VPN Multisegment Pseudowires
          

           
	 
          

           The L2VPN Multisegment Pseudowires feature enables you to configure two or more Layer 2 pseudowire segments that function as a single pseudowire. Layer 2 Virtual Private Network (L2VPN) multisegment pseudowires span multiple cores or autonomous systems of the same or different carrier networks. L2VPN multisegment pseudowires are also used in L2VPN Virtual Private LAN Services (VPLS) Inter-AS Option B networks. 
	 
          

           This document explains Multiprotocol Label Switching (MPLS) Operations, Administration, and Maintenance (OAM) Support for L2VPN Multisegment Pseudowires and the MPLS OAM Support for the L2VPN VPLS Inter-AS Option B feature. These features allow you to use 
		ping 
		  mpls and 
		trace 
		  mpls commands to ensure pseudowire connectivity. 
	 
          

          

          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 L2VPN Multisegment Pseudowires
          


          

          Restrictions for L2VPN Multisegment Pseudowires
          

          • 
Only Multiprotocol Label Switching (MPLS) Layer 2 pseudowires are supported.

            • 

          • 
In Cisco IOS Release 12.3(33)SRE, only static configuration of the pseudowires is supported for the L2VPN Multisegment Pseudowires feature.

            • 

          • 
In Cisco IOS Release 15.1(1)S, dynamic configuration of the pseudowires is supported and required for the L2VPN VPLS Inter-AS Option B feature. 

            • 

          • 
In Cisco IOS Release 12.3(33)SRE, only pseudowires advertised with forwarding equivalence class (FEC) 128 are supported for the L2VPN Multisegment Pseudowires feature. FEC 129 is not supported. 

            • 

          • 
In Cisco IOS Release 15.1(1)S, FEC 129 is supported and used to exchange information about the pseudowires for the L2VPN VPLS Inter-AS Option B feature.

            • 

          • 
The S-PE router is limited to 1600 pseudowires.

            • 

          

          

          

          Information About L2VPN Multisegment Pseudowires
          

          

          L2VPN Pseudowire Defined
          

           An L2VPN pseudowire (PW) is a tunnel established between two provider edge (PE) routers across the core carrying the Layer 2 payload encapsulated as MPLS data, as shown in the figure below. This helps carriers migrate from traditional Layer 2 networks such as Frame Relay and ATM to an MPLS core. The PWs between two PE routers are located within the same autonomous system (AS). Routers PE1 and PE2 are called terminating PE routers (T-PEs). Attachment circuits are bounded to the PW on these PE routers. 
	 
          

          Figure 1. An L2VPN Pseudowire

          

          

          

          L2VPN Multisegment Pseudowire Defined
          

           An L2VPN multisegment pseudowire (MS-PW) is a set of two or more PW segments that function as a single PW, as shown in the figure below. It is also known as switched PW. MS-PWs span multiple cores or autonomous systems of the same or different carrier networks. An L2VPN MS-PW can include up to 254 PW segments. 
	 
          

          Figure 2. A Multisegment Pseudowire

          

           The end routers are called terminating PE routers (T-PEs), and the switching routers are called S-PE routers. The S-PE router terminates the tunnels of the preceding and succeeding PW segments in an MS-PW. The S-PE router can switch the control and data planes of the preceding and succeeding PW segments of the MS-PW. An MS-PW is declared to be up when all the single-segment PWs are up. For more information, see the L2VPN Pseudowire Switching document. 
	 
          

           With the L2VPN Multisegment Pseudowire feature introduced in Cisco IOS Release 12.2(33)SRE, the pseudowires are created statically, and FEC 128 information is used to exchange the information about each AS. 
	 
          

          

          

          MPLS OAM Support for Multisegment Pseudowires
          

          
You can use the ping mpls and trace mplscommands to verify that all the segments of the MPLS multisegment pseudowire are operating. 
          

          
You can use the ping mpls command to verify connectivity at the following pseudowire points:
          

          • 
From one end of the pseudowire to the other

            • 

          • 
From one of the pseudowires to a specific segment

            • 

          • 
The segment between two adjacent S-PE routers

            • 

          

          
You can use the trace mplscommand to verify connectivity at the following pseudowire points:
          

          • 
From one end of the pseudowire to the other

            • 

          • 
From one of the pseudowires to a specific segment

            • 

          • 
The segment between two adjacent S-PE routers

            • 

          • 
A range of segments

            • 

          

          

          

          MPLS OAM Support for L2VPN VPLS Inter-AS Option B
          

           The L2VPN VPLS Inter-AS Option B feature introduced in Cisco IOS Release 15.1(1)S uses multisegment pseudowires to connect Autonomous System Border Routers (ASBRs) in different autonomous systems. With this feature, the pseudowires are created dynamically, and FEC 129 information is used to exchange the information about each ASBR. 
	 
          

           The differences between static multisegment pseudowires and dynamic multisegment pseudowires are listed in the table below. 
	 
          


          Table 1 Comparison of Static and Dynamic Multisegment Pseudowires 
           
				
           Static Multisegment Pseudowires
				
          
 
			           		
 
				
           Dynamic Multisegment Pseudowires
				
          
 
			           		

          
          

           
				
           Are statically stitched and dynamically signalled.
				
          
 
			           		
 
				
           Are dynamically stitched and dynamically signalled.
				
          
 
			           		

          

           
				
           Label Distribution Protocol (LDP) exchanges the type length value (TLV) and FEC 128 information is exchanged between segments.
				
          
 
			           		
 
				
           Border Gateway Protocol (BGP) exchanges the TLV and FEC 129 information is exchanged between ASBRs.
				
          
 
			           		

          
          

          

          

           For more information about the L2VPN VPLS Inter-AS Option B feature, see L2VPN VPLS Inter-AS Option B. 
	 
          

          

          

          

          How to Configure L2VPN Multisegment Pseudowires
          

          

          Configuring L2VPN Multisegment Pseudowires
          

          
Perform the following steps on the S-PE routers to create L2VPN multisegment pseudowires. 
          

          

          Cisco 7600 Router-Specific Instructions
          

          
      
          
If the Cisco 7600 router is the penultimate hop router connected to the S-PE or T-PE router, issue the following commands on the S-PE or T-PE routers:
          

      
          • 
          
            mpls
            ldp
            explicit-null
          
        

            • 

          • 
          
            no
            mls
            mpls
            explicit-null
            propagate-ttl
          
        

            • 

          

    
          
SUMMARY STEPS
            1.   
      
          
            enable
          
        
            

            2.   
      
          
            configure
            terminal
          
        
            

            3.   
      
          
            mpls
            label
            protocol
            ldp
          
        
            

            4.   
      
          
            mpls
            ldp
            router-id
          
          
            interface
          
          
            force
          
        
            

            5.   
      
          
            pseudowire-class
          
          
            name
          
        
            

            6.   
      
          
            encapsulation
            mpls
          
        
            

            7.   
      
          
            switching
            tlv
          
        
            

            8.   
      
          
            exit
          
        
            

            9.   
      
          
            l2
            vfi
          
          
            name
          
          
            
            
          
          
            point-to-point
          
        
            

            10.   
      
          
            description
          
          
            string
          
        
            

            11.   
      
          
            neighbor
          
          
            ip-address
            vcid
          
          
            {
          
          
            encapsulation
            mpls
           
|
 pw-class pw-class-name }
            


          DETAILED STEPS
             Command or ActionPurpose
            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
          
            mpls
            label
            protocol
            ldp
          
        
             

            Example:
            
          
            Router(config)# mpls label protocol ldp

            

        
            
 
                  		 
          
            
Configures the use of Label Distribution Protocol (LDP) on all interfaces.
            

         
      
            

            Step 4
          
            mpls
            ldp
            router-id
          
          
            interface
          
          
            force
          
        
             

            Example:
            
          
            Router(config)# mpls ldp router-id loopback0 force
            

        
            
 
                  		 
          
            
Specifies the preferred interface for determining the LDP router ID. 
            

         
      
            

            Step 5
          
            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 6
          
            encapsulation
            mpls
          
        
             

            Example:
            
          
            Router(config-pw-class)# encapsulation mpls 
            

        
            
 
                  		 
          
            
Specifies the tunneling encapsulation. 
            

          
            • 
For MPLS L2VPNs, the encapsulation type is mpls.

              • 

            

         
      
            

            Step 7
          
            switching
            tlv
          
        
             

            Example:
            
          
            Router(config-pw-class)# switching tlv
            

        
            
 
                  		 
          
            
(Optional) Enables the advertisement of the switching point type-length variable (TLV) in the label binding. 
            

          
            • 
This command is enabled by default. 

              • 

            

         
      
            

            Step 8
          
            exit
          
        
             

            Example:
            
          
            Router(config-pw-class)# exit
            

        
            
 
                  		 
          
            
Exits pseudowire class configuration mode.
            

         
      
            

            Step 9
          
            l2
            vfi
          
          
            name
          
          
            
            
          
          
            point-to-point
          
        
             

            Example:
            
          
            Router(config)# l2 vfi atomtunnel point-to-point 
            

        
            
 
                  		 
          
            
Creates a point-to-point Layer 2 virtual forwarding interface (VFI) and enters VFI configuration mode. 
            

         
      
            

            Step 10
          
            description
          
          
            string
          
        
             

            Example:
            
          
            Router(config-vfi)# description segment1
            

        
            
 
                  		 
          
            
Provides a description of the switching provider edge router for a multisegment pseudowire.
            

         
      
            

            Step 11
          
            neighbor
          
          
            ip-address
            vcid
          
          
            {
          
          
            encapsulation
            mpls
           
|
 pw-class pw-class-name }
             

            Example:
            
          
            Router(config-vfi)# neighbor 10.0.0.1 100 pw-class mpls 
            

        
            
 
                  		 
          
            
Sets up an emulated VC. 
            

          
            • 
Specify the IP address and the VC ID of the peer router. Also specify the pseudowire class to use for the emulated VC. 

              • 

            

          
            Note   
                
              
            
Only two neighborcommands are allowed for each l2 vfi point-to-point command. 
            

            

         
      
            

            

            

            

            

            Displaying Information About the L2VPN Multisegment Pseudowires
            

            
      
            
Perform the following task to display the status of L2VPN multisegment pseudowires.
            

    
            
SUMMARY STEPS
              1.   
      
          
            show
            mpls
            l2transport
            binding
          
        
              

              2.   
      
          
            show
            mpls
            l2transport
            vc
            detail
          
        
              


            DETAILED STEPS
              Step 1  
             
          
            show
            mpls
            l2transport
            binding
          
        
               
          
              
Use the show mpls l2transport binding command to display information about the pseudowire switching point, as shown in bold in the output. (In the following examples PE1 and PE4 are the T-PE routers.)
              

         

              Example:
              
          
              Router# show mpls l2transport binding
 
  Destination Address: 10.1.1.1,  VC ID: 102
    Local Label:  17
        Cbit: 1,    VC Type: Ethernet,    GroupID: 0
        MTU: 1500,   Interface Desc: n/a
        VCCV: CC Type: CW [1], RA [2], TTL [3]
              CV Type: LSPV [2]
    Remote Label: 16
        Cbit: 1,    VC Type: Ethernet,    GroupID: 0
        MTU: 1500,   Interface Desc: n/a
        VCCV: CC Type: CW [1], RA [2], TTL [3]
              CV Type: LSPV [2]
        PW Switching Point:
             Vcid   local IP addr      remote IP addr      Description
             101        10.11.11.11    10.20.20.20         PW Switching Point PE3
             100        10.20.20.20    10.11.11.11            PW Switching Point PE2

              

        
              
 
          
              
          
              

        
              

              Step 2  
             
          
            show
            mpls
            l2transport
            vc
            detail
          
        
               
          
              
Use the show mpls l2transport vc detail command to display status of the pseudowire switching point. In the following example, the output (shown in bold) displays the segment that is the source of the fault of the multisegment pseudowire:
              

         

              Example:
              
          
              Router# show mpls l2transport vc detail
Local interface: Se3/0 up, line protocol up, HDLC up
  Destination address: 12.1.1.1, VC ID: 100, VC status: down
    Output interface: Se2/0, imposed label stack {23}
    Preferred path: not configured  
    Default path: active
    Next hop: point2point
  Create time: 00:03:02, last status change time: 00:01:41
  Signaling protocol: LDP, peer 10.1.1.1:0 up
    Targeted Hello: 10.1.1.4(LDP Id) -> 10.1.1.1, LDP is UP
    Status TLV support (local/remote)   : enabled/supported
      LDP route watch                   : enabled
      Label/status state machine        : established, LruRrd
      Last local dataplane   status rcvd: No fault
      Last local SSS circuit status rcvd: No fault
      Last local SSS circuit status sent: DOWN(PW-tx-fault)
      Last local  LDP TLV    status sent: No fault
      Last remote LDP TLV    status rcvd: DOWN(PW-tx-fault)
       PW Switching Point:
       Fault type  Vcid   local IP addr   remote IP addr   Description
       PW-tx-fault  101   10.1.1.1        10.1.1.1         S-PE2
      Last remote LDP ADJ    status rcvd: No fault
    MPLS VC labels: local 19, remote 23 
    Group ID: local 0, remote 0
    MTU: local 1500, remote 1500
    Remote interface description: 
  Sequencing: receive disabled, send disabled
  VC statistics:
    packet totals: receive 16, send 27
    byte totals:   receive 2506, send 3098
    packet drops:  receive 0, seq error 0, send 0
              

        
              

              

              

              

              

              Verifying Multisegment Pseudowires with ping mpls and trace mpls Commands
              

               
		
               You can use 
		  ping 
			 mpls and 
		  trace 
			 mpls commands to verify connectivity in multisegment pseudowires. 
		
              
 
		

              Note
               
		  
               Some 
			 ping 
			 mpls and 
				trace 
				mplskeywords that are available with IPv4 LDP or traffic engineering (TE) are not available with pseudowire.
		  
              
 
		  
               The following keywords are not available with the 
			 ping 
				mpls 
			  
			 pseudowire 
			 command:
		  
              
 
		  
              •  
				 
				  dsmap 
				 
			 

                • 

              •  
				 
				  flags 
				 
			 

                • 

              •  
				 
				  force-explicit-null 
				 
			 

                • 

              •  
				 
				  output 
				 
			 

                • 

              •  
				 
				  revision 
				 
			 

                • 

              •  
				 
				  ttl 
				 
			 

                • 

              
 
		  
               The following keywords are not available with the 
			 trace 
				mpls 
			  
			 pseudowire 
			 command:
		  
              
 
		  
              •  
				 
				  flags 
				 
			 

                • 

              •  
				 
				  force-explicit-null 
				 
			 

                • 

              •  
				 
				  output 
				 
			 

                • 

              •  
				 
				  revision 
				 
			 

                • 

              •  
				 
				  ttl 
				 
			 

                • 

              
 >
		
              
 
	 
              
SUMMARY STEPS
                1.   
       
			  
				ping 
				mpls 
				pseudowire 
			  
			  
				destination-address 
				vc-id 
			  [segment 
			 segment-number]
		  
                

                2.   
       
			  
				trace 
				mpls 
				pseudowire 
			  
			  
				destination-address 
				vc-id 
			  
			  
				segment 
			  
			  
				segment-number 
			  [segment-number 
			 ]
		  
                


              DETAILED STEPS
                Step 1  
              
			  
				ping 
				mpls 
				pseudowire 
			  
			  
				destination-address 
				vc-id 
			  [segment 
			 segment-number]
		  
                  
			 
                 Where:
			 
                
 
			 
                •  
				   
					 destination-address 
				   is the address of the S-PE router, which is the end of the segment from the direction of the source. 
				

                  • 

                •  
				   
					 vc-id 
				   is the VC ID of the segment from the source to the next PE router. 
				

                  • 

                •  
				   
					 segment 
				   
				   
					 segment-number 
				   
				   
					  
					  
					 is 
					 optional 
					 and 
					 specifies 
					 the 
					 segment 
					 you 
					 want 
					 to 
					 ping. 
				   
				

                  • 

                
 
			 
                 The following examples use the topology shown in the second figure above:
			 
                
 
			 
                •  To perform an end-to-end ping operation from T-PE1 to T-PE2, enter the following command. 
				  destination-address is S-PE1 and 
				  vc-idis the VC between T-PE1 and S-PE1.
				

                  • 

                
 
			 
                 
				 
				  ping 
				  mpls 
				  pseudowire 
				 
				 
				  destination-address 
				  vc-id 
				 
			 
                
 
			 
                •  To perform a ping operation from T-PE1 to segment 2, enter the following command. destination-address is S-PE1 and 
				  vc-idis the VC between T-PE1 and S-PE1.
				

                  • 

                
 
			 
                 
				 
				  ping 
				  mpls 
				  pseudowire 
				 
				 
				  destination-address 
				  vc-id 
				 
				 
				   
				   
				 
				 
				  segment 
				  2 
				 
			 
                
 
		   

                Example:
                 
			 
                
 
		  
                

                

                Step 2  
              
			  
				trace 
				mpls 
				pseudowire 
			  
			  
				destination-address 
				vc-id 
			  
			  
				segment 
			  
			  
				segment-number 
			  [segment-number 
			 ]
		  
                  
			 
                 Where: 
			 
                
 
			 
                •  
				   
					 destination-address 
				   
				   
					  
					  
					 is 
					 the 
					 address 
					 of 
					 the 
					 next 
					 S-PE 
					 router 
					 from 
					 the 
					 origin 
					 of 
					 the 
					 trace. 
				   
				

                  • 

                •  
				   
					 vc-id 
				   is the VC ID of the segment from which the 
				  trace command is issued.
				

                  • 

                •  
				   
					 segment-number 
				   indicates the segment upon which the trace operation will act. If you enter two segment numbers, the traceroute operation will perform a trace on that range of routers. 
				

                  • 

                
 
			 
                 The following examples use the topology shown in the second figure above:
			 
                
 
			 
                •  To perform a trace operation from T-PE1 to segment 2 of the multisegment pseudowire, enter the following command. 
				  destination-address is S-PE1 and 
				  vc-idis the VC between T-PE1 and S-PE1.
				

                  • 

                
 
			 
                 
				 
				  trace 
				  mpls 
				  pseudowire 
				 
				 
				  destination-address 
				  vc-id 
				 
				 
				  segment 
				  2 
				 
			 
                
 
			 
                 This example performs a trace from T-PE1 to S-PE2.
			 
                
 
			 
                •  To perform a trace operation on a range of segments, enter the following command. This example performs a trace from S-PE2 to T-PE2. 
				  destination-address is S-PE1 and 
				  vc-id 
				  is the VC between T-PE1 and S-PE1.
				

                  • 

                
 
			 
                 
				 
				  trace 
				  mpls 
				  pseudowire 
				 
				 
				  destination-address 
				  vc-id 
				 
				 
				   
				   
				  segment 
				  2 
				  4 
				 
			 
                
 
			 
                 The following commands perform trace operations on S-PE router 10.10.10.9, first on segment 1, then on segment 2.
			 
                
 
			 
                 Segment 1 trace: 
			 
                
 
		   

                Example:
                 
			 
                Router# trace mpls pseudowire 10.10.10.9 220 segment 1
Tracing MS-PW segments within range [1-1] peer address 10.10.10.9 and timeout 2 seconds
Codes: '!' - success, 'Q' - request not sent, '.' - timeout,
  'L' - labeled output interface, 'B' - unlabeled output interface,
  'D' - DS Map mismatch, 'F' - no FEC mapping, 'f' - FEC mismatch,
  'M' - malformed request, 'm' - unsupported tlvs, 'N' - no label entry,
  'P' - no rx intf label prot, 'p' - premature termination of LSP,
  'R' - transit router, 'I' - unknown upstream index,
  'X' - unknown return code, 'x' - return code 0
Type escape sequence to abort.
L 1 10.10.9.9 0 ms [Labels: 18 Exp: 0]
    local 10.10.10.22 remote 10.10.10.9 vc id 220
Segment 2 trace:
Router# trace mpls pseudowire 10.10.10.9 220 segment 2
Tracing MS-PW segments within range [1-2] peer address 10.10.10.9 and timeout 2 seconds
Codes: '!' - success, 'Q' - request not sent, '.' - timeout,
  'L' - labeled output interface, 'B' - unlabeled output interface,
  'D' - DS Map mismatch, 'F' - no FEC mapping, 'f' - FEC mismatch,
  'M' - malformed request, 'm' - unsupported tlvs, 'N' - no label entry,
  'P' - no rx intf label prot, 'p' - premature termination of LSP,
  'R' - transit router, 'I' - unknown upstream index,
  'X' - unknown return code, 'x' - return code 0
Type escape sequence to abort.
L 1 10.10.9.9 4 ms [Labels: 18 Exp: 0]
    local 10.10.10.22 remote 10.10.10.9 vc id 220
! 2 10.10.3.3 4 ms [Labels: 16 Exp: 0]
    local 10.10.10.9 remote 10.10.10.3 vc id 220
                
 
		  
                

                

                

                

                

                Verifying L2VPN VPLS Inter-AS Option B with ping mpls and trace mpls Commands
                

                 
		
                 You can use 
			 ping 
			 mplsand 
		  trace 
			 mpls commands to verify connectivity in configurations using the L2VPN VPLS Inter-AS Option B feature. For end-to-end ping and trace operations, you enter the destination address of the T-PE router at the other end of the pseudowire.
		
                
 
		

                Note
                 
		  
                 Some 
			 ping 
				mplsand 
			 trace 
				mplskeywords that are available with IPv4 LDP or traffic engineering (TE) are not available with pseudowire.
		  
                
 
		  
                 The following keywords are not available with the 
			 ping 
				mpls 
			  
			 pseudowire 
			 command:
		  
                
 
		  
                •  
				 
				  dsmap 
				 
			 

                  • 

                •  
				 
				  flags 
				 
			 

                  • 

                •  
				 
				  force-explicit-null 
				 
			 

                  • 

                •  
				 
				  output 
				 
			 

                  • 

                •  
				 
				  revision 
				 
			 

                  • 

                •  
				 
				  ttl 
				 
			 

                  • 

                
 
		  
                 The following keywords are not available with the 
			 trace 
				mpls 
			  
			 pseudowire 
			 command:
		  
                
 
		  
                •  
				 
				  flags 
				 
			 

                  • 

                •  
				 
				  force-explicit-null 
				 
			 

                  • 

                •  
				 
				  output 
				 
			 

                  • 

                •  
				 
				  revision 
				 
			 

                  • 

                •  
				 
				  ttl 
				 
			 

                  • 

                
 >
		
                
 
	 
                
SUMMARY STEPS
                  1.   
       
			  
				ping 
				mpls 
				pseudowire 
			  
			  
				destination-address 
				vc-id 
			  [segment 
			 segment-number]
		  
                  

                  2.   
       
			  
				trace 
				mpls 
				pseudowire 
			  
			  
				destination-address 
				vc-id 
			  
			  
				segment 
			  
			  
				segment-number 
			  [segment-number 
			 ]
		  
                  


                DETAILED STEPS
                  Step 1  
              
			  
				ping 
				mpls 
				pseudowire 
			  
			  
				destination-address 
				vc-id 
			  [segment 
			 segment-number]
		  
                    
			 
                   Where:
			 
                  
 
			 
                  •  
				   
					 destination-address 
				  is the address of the T-PE2 router at the other end of the pseudowire. 
				

                    • 

                  •  
				   
					 vc-id 
				   is the VC ID between T-PE1 and S-PE1.
				

                    • 

                  •  
				   
					 segment 
				   
				   
					 segment-number 
				   
				   
					  
					  
					 is 
					 optional 
					 and 
					 specifies 
					 the 
					 segment 
					 you 
					 want 
					 to 
					 ping. 
				   
				

                    • 

                  
 
			 
                   The following examples use the topology shown in the second figure above:
			 
                  
 
			 
                  •  To perform an end-to-end ping operation from T-PE1 to T-PE2, enter the following command. destination-address is T-PE2 and 
				  vc-idis the VC between T-PE1 and S-PE1.
				

                    • 

                  
 
			 
                   
				 
				  ping 
				  mpls 
				  pseudowire 
				 
				 
				  destination-address 
				  vc-id 
				 
			 
                  
 
		   

                  Example:
                   
			 
                  
 
		  
                  

                  

                  Step 2  
              
			  
				trace 
				mpls 
				pseudowire 
			  
			  
				destination-address 
				vc-id 
			  
			  
				segment 
			  
			  
				segment-number 
			  [segment-number 
			 ]
		  
                    
			 
                   Where: 
			 
                  
 
			 
                  •  
				   
					 destination-address 
				  is the address of the T-PE2 router at the other end of the pseudowire.
				

                    • 

                  •  
				   
					 vc-id 
				   is the VC ID between T-PE1 and S-PE1.
				

                    • 

                  •  
				   
					 segment-number 
				   indicates the segment upon which the trace operation will act. If you enter two segment numbers, the traceroute operation will perform a trace on that range of routers. 
				

                    • 

                  
 
			 
                   The following examples use the topology shown in the second figure above:
			 
                  
 
			 
                  •  To perform a trace operation from T-PE1 to T-PE2, enter the following command. 
				  destination-addressis T-PE2 and 
				  vc-idis the VC between T-PE1 and S-PE1.
				

                    • 

                  
 
			 
                   
				 
				  trace 
				  mpls 
				  pseudowire 
				 
				 
				  destination-address 
				  vc-id 
				 
				 
				  segment 
				 
				 
				  2 
				 
			 
                  
 
			 
                   This example performs a trace from T-PE1 to T-PE2.
			 
                  
 
			 
                  •  To perform a trace operation on a range of segments, enter the following command. This example performs a trace from S-PE2 to T-PE2. 
				  destination-addressis S-PE1 and 
				  vc-id 
				  is the VC between T-PE1 and S-PE1.
				

                    • 

                  
 
			 
                   
				 
				  trace 
				  mpls 
				  pseudowire 
				 
				 
				  destination-address 
				  vc-id 
				 
				 
				  segment 
				  2 
				  4 
				 
			 
                  
 
		  
                  

                  

                  

                  

                  

                  Configuration Examples for L2VPN Multisegment Pseudowires
                  

                  

                  Example  Configuring an L2VPN Multisegment Pseudowire
                  

                  
      
                  
The following example does not include all the commands. Unconfigured interfaces are not shown. Portions of the example relevant to L2VPN Multisegment Pseudowires are shown in bold. 
                  

    
                  

                  T-PE1 Configuration
                  
      
      
                  no ipv6 cef
multilink bundle-name authenticated
frame-relay switching
mpls traffic-eng tunnels
mpls ldp discovery targeted-hello accept
no mpls ip propagate-ttl forwarded
mpls label protocol ldp
!
policy-map exp2
!
interface Loopback0
 ip address 10.131.191.252 255.255.255.255
 no clns route-cache
!         
interface Ethernet0/0
 ip address 10.131.191.230 255.255.255.252
 mpls label protocol ldp
 mpls ip
 no clns route-cache
 ip rsvp bandwidth 1500 1500
 ip rsvp signalling dscp 0
!
interface Ethernet1/0
 ip address 10.131.159.246 255.255.255.252
shutdown 
 no clns route-cache
!
interface Ethernet2/0
 no ip address
 no cdp enable
!
interface Ethernet2/0.1
 encapsulation dot1Q 1000
 xconnect 10.131.191.251 333 encapsulation mpls
!
router ospf 1
 log-adjacency-changes
 passive-interface Loopback0
 network 10.131.159.244 0.0.0.3 area 0
 network 10.131.191.228 0.0.0.3 area 0
 network 10.131.191.232 0.0.0.3 area 0
 network 10.131.191.252 0.0.0.0 area 0
 network 11.0.0.0 0.0.0.3 area 0
 mpls traffic-eng router-id Loopback0
 mpls traffic-eng area 0
!
ip classless
!
no ip http server
!
mpls ldp router-id Loopback0 force
end
                  

    
                  

                  S-PE1 Configuration
                  
      
      
                  no ipv6 cef
multilink bundle-name authenticated
mpls traffic-eng tunnels
no mpls traffic-eng auto-bw timers
mpls ldp discovery targeted-hello accept
no mpls ip propagate-ttl forwarded
mpls label protocol ldp
!
policy-map exp2
!
l2 vfi sam-sp point-to-point
 neighbor 10.131.191.252 333 encapsulation mpls
 neighbor 10.131.159.251 222 encapsulation mpls
!         
interface Tunnel3
 ip unnumbered Loopback0
 shutdown
 mpls label protocol ldp
 mpls accounting experimental input
 mpls ip
 tunnel mode mpls traffic-eng
 tunnel destination 10.131.159.252
 tunnel mpls traffic-eng autoroute announce
 tunnel mpls traffic-eng priority 2 2
 tunnel mpls traffic-eng bandwidth 512
 tunnel mpls traffic-eng path-option 1 dynamic
 no clns route-cache
 service-policy output exp2
!
interface Loopback0
 ip address 10.131.191.251 255.255.255.255
 no clns route-cache
!
interface Ethernet0/0
 ip address 10.131.191.229 255.255.255.252
 mpls traffic-eng tunnels
 mpls label protocol ldp
 mpls ip
 no clns route-cache
 ip rsvp bandwidth 1500 1500
 ip rsvp signalling dscp 0
!
interface Ethernet1/0
 ip address 10.131.159.226 255.255.255.252
 mpls traffic-eng tunnels
 mpls ip
 no clns route-cache
service-policy output exp2
 ip rsvp bandwidth 1500 1500
 ip rsvp signalling dscp 0
!
interface Serial2/0
 ip unnumbered Loopback0
 mpls ip
 no fair-queue
 no keepalive
 serial restart-delay 0
 no clns route-cache
!         
router ospf 1
 log-adjacency-changes
 passive-interface Loopback0
 network 10.131.159.224 0.0.0.3 area 0
 network 10.131.191.228 0.0.0.3 area 0
 network 10.131.191.251 0.0.0.0 area 0
 mpls traffic-eng router-id Loopback0
 mpls traffic-eng area 0
!
ip classless
!         
end
                  

    
                  

                  T-PE2 Configuration
                  
      
      
                  no ipv6 cef
no l2tp congestion-control
multilink bundle-name authenticated
frame-relay switching
mpls traffic-eng tunnels
no mpls traffic-eng auto-bw timers frequency 0
mpls ldp discovery targeted-hello accept
no mpls ip propagate-ttl forwarded
mpls label protocol ldp
!
interface Loopback0
 ip address 10.131.159.252 255.255.255.255
 no clns route-cache
!
interface Ethernet0/0
 ip address 10.131.159.230 255.255.255.252
interface Ethernet0/0
 ip address 10.131.159.230 255.255.255.252
 mpls traffic-eng tunnels
 mpls ip
 no clns route-cache
 ip rsvp bandwidth 1500 1500
 ip rsvp signalling dscp 0
!
interface Ethernet1/0
 ip address 10.131.159.245 255.255.255.252
 shutdown
 mpls ip
 no clns route-cache
!
interface Ethernet3/0.1
 encapsulation dot1Q 1000
 xconnect 10.131.159.251 111 encapsulation mpls
!
router ospf 1
 log-adjacency-changes
 passive-interface Loopback0
 network 10.131.122.0 0.0.0.3 area 0
 network 10.131.159.228 0.0.0.3 area 0
 network 10.131.159.232 0.0.0.3 area 0
 network 10.131.159.244 0.0.0.3 area 0
 network 10.131.159.252 0.0.0.0 area 0
 network 11.0.0.0 0.0.0.3 area 0
 network 19.0.0.0 0.0.0.255 area 0
 mpls traffic-eng router-id Loopback0
 mpls traffic-eng area 0
end
                  

    
                  

                  S-PE2 configuration
                  
      
      
                  no ipv6 cef
no l2tp congestion-control
multilink bundle-name authenticated
mpls traffic-eng tunnels
no mpls traffic-eng auto-bw timers frequency 0
mpls ldp discovery targeted-hello accept
no mpls ip propagate-ttl forwarded
mpls label protocol ldp
!
l2 vfi sam-sp point-to-point
 neighbor 10.131.159.252 111 encapsulation mpls
 neighbor 10.131.191.251 222 encapsulation mpls
!
!
interface Loopback0
 ip address 10.131.159.251 255.255.255.255
!
interface Ethernet0/0
interface Ethernet0/0
 ip address 10.131.159.229 255.255.255.252
 mpls traffic-eng tunnels
 mpls accounting experimental input
 mpls ip
 ip rsvp bandwidth 1500 1500
 ip rsvp signalling dscp 0
!
interface Ethernet1/0
 ip address 10.131.159.225 255.255.255.252
 mpls traffic-eng tunnels
 mpls ip
 ip rsvp bandwidth 1500 1500
 ip rsvp signalling dscp 0
!
router ospf 1
 log-adjacency-changes
 passive-interface Loopback0
 network 10.131.159.224 0.0.0.3 area 0
 network 10.131.159.228 0.0.0.3 area 0
 network 10.131.159.251 0.0.0.0 area 0
 network 19.0.0.0 0.0.0.255 area 0
 mpls traffic-eng router-id Loopback0
 mpls traffic-eng area 0
!
end
                  

    
                  

                  

                  

                  

                  Additional References
                  

                   
	 
                  

                  Related Documents
                   
		 
		

                   
					 
                   Related Topic
					 
                  
 
				                    		
 
					 
                   Document Title
					 
                  
 
				                    		

                  
                  

                   
					 
                   Cisco IOS commands
					 
                  
 
				                    		
 
					 
                   
						Cisco IOS Master Commands List, All Releases 
					 
                  
 
				                    		

                  

                   
					 
                   MPLS commands
					 
                  
 
				                    		
 
					 
                   
						Cisco IOS Multiprotocol Label Switching Command Reference 
					 
                  
 
				                    		

                  

                   
					 
                   Layer 2 VPNS
					 
                  
 
				                    		

                   
					 
                  •  Any Transport over MPLS 
						

                    • 

                  •  L2VPN Pseudowire Switching 
						

                    • 

                  •  MPLS LSP Ping/Traceroute for LDP/TE, and LSP Ping for VCCV 
						

                    • 

                  
 
				  
                  
                  		

                  

                   
					 
                   L2VPN VPLS Inter-AS Option B
					 
                  
 
				                    		
 
					 
                   L2VPN VPLS Inter-AS Option B 
					 
                  
 
				                    		

                  
                  

                  

                  
 
	 
                  

                  Standards
                   
		 
		

                   
					 
                   Standard
					 
                  
 
				                    		
 
					 
                   Title
					 
                  
 
				                    		

                  
                  

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

                  
                  

                  

                  
 
	 
                  

                  MIBs
                   
		 
		

                   
					 
                   MIB
					 
                  
 
				                    		
 
					 
                   MIBs Link
					 
                  
 
				                    		

                  
                  

                   
					 
                   No new or modified MIBs are supported by this feature, and support for existing MIBs has not been modified by this feature.
					 
                  
 
				                    		
 
					 
                   To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:
					 
                  
 
					 
                   
						http:/​/​www.cisco.com/​go/​mibs 
					 
                  
 
				                    		

                  
                  

                  

                  
 
	 
                  

                  RFCs
                   
		 
		

                   
					 
                   RFC
					 
                  
 
				                    		
 
					 
                   Title
					 
                  
 
				                    		

                  
                  

                   
					 
                   RFC 4379
					 
                  
 
				                    		
 
					 
                   
						http:/​/​tools.ietf.org/​html/​rfc4379 Detecting Multi-Protocol Label Switched (MPLS) Data Plane Failures 
					 
                  
 
				                    		

                  

                   
					 
                   RFC 4447
					 
                  
 
				                    		
 
					 
                   
						Pseudowire Setup and Maintenance Using the Label Distribution Protocol (LDP) 
					 
                  
 
				                    		

                  

                   
					 
                   RFC 5085
					 
                  
 
				                    		
 
					 
                   
						Pseudowire Virtual Circuit Connectivity Verification (VCCV) 
					 
                  
 
				                    		

                  
                  

                  

                  
 
	 
                  

                  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 L2VPN Multisegment Pseudowires
                  

                   
		
                  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 2 Feature Information for L2VPN Multisegment Pseudowires 
                   
				  
                   Feature Name
				  
                  
 
				                  		
 
				  
                   Releases
				  
                  
 
				                  		
 
				  
                   Feature Information
				  
                  
 
				                  		

                  
                  

                   
				  
                   L2VPN Multisegment Pseudowires 
				  
                  
 
				                  		
 
				  
                   12.2(33)SRE
				  
                  
 
				                  		
 
				  
                   This feature enables you to configure two or more Layer 2 pseudowire segments that function as a single pseudowire. The feature spans multiple cores or autonomous systems of the same or different carrier networks. 
				  
                  
 
				                  		

                  

                   
				  
                   MPLS OAM Support for Multisegment Pseudowires
				  
                  
 
				                  		
 
				  
                   12.2(33)SRE
				  
                  
 
				                  		
 
				  
                   This feature enables you to use the 
					 ping 
					 mpls and 
						trace 
						mplscommands to verify that all the segments of the MPLS multisegment pseudowire are operating. 
				  
                  
 
				                  		

                  

                   
				  
                   MPLS OAM Support for L2VPN VPLS Inter-AS Option B
				  
                  
 
				                  		
 
				  
                   15.1(1)S
				  
                  
 
				                  		
 
				  
                   This feature is an enhancement to the MPLS OAM Support for Multisegment Pseudowires feature. This feature allows you to use the 
					 ping 
					 mpls and 
						trace 
						mplscommands to verify the pseudowire used in a L2VPN VPLS Inter-AS Option B configuration.