Segment Routing v6 Configuration Guide for Cisco 8000 Series Routers, Cisco IOS XR Releases

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Segment Routing v6 Configuration Guide for Cisco 8000 Series Routers, Cisco IOS XR Releases

Static SRv6 pseudowire

Updated: September 8, 2026

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Explains how a static pseudowire provides single-homing VPWS connectivity between PEs across an SRv6 core without requiring control-plane signaling.

Static SRv6 pseudowire (PW) gives the flexibility to

configure single-homing static SRv6 pseudowire between two Provider Edge (PE) routers, in an SRv6 core plane, and
extends Virtual Private Wire Service (VPWS) capabilities by incorporating SRv6.

Table 1. Feature History Table
Feature Name	Release Information	Feature Description
Static SRv6 pseudowire	Release 25.4.1	Introduced in this release on: Fixed Systems (8700 [ASIC: K100])(select variants only) This feature is supported on Cisco 8711-48Z-M routers.
Static SRv6 pseudowire	Release 25.1.1	Introduced in this release on: Fixed Systems (8200 [ASIC: P100, Q200] (select variants only); Modular Systems (8800 [LC ASIC: P100]); Centralized Systems (8600 [ASIC: Q200]) You can now create a virtual connection between two endpoints over an IPv6 network using SRv6. Unlike dynamic pseudowires, which rely on signaling protocols to establish and maintain connections, static pseudowires are manually configured and do not require a control plane for setup. This enhancement allows operators to extend the existing Virtual Private Wire Service (VPWS) capabilities by incorporating SRv6, providing improved flexibility and scalability for service providers. This feature is supported on: 8201-32FH

Key aspects of SRv6 static pseudowire

This feature enhances the existing Virtual Private Wire Service (VPWS) by incorporating SRv6 capabilities, which previously supported only MPLS.

This enhancement enables the configuration and management of static SRv6 pseudowires, thereby providing enhanced flexibility and scalability for service providers. Additionally, it addresses the specific requirements of customers who require static configuration for their network services.

Static configuration: Unlike dynamic pseudowires that rely on signaling protocols like LDP or BGP, static pseudowires are manually configured. This allows for more control and customization in specific network scenarios.
Pseudowire (PW): A pseudowire is a mechanism that emulates the properties of a traditional telecommunications circuit over a packet-switched network. It allows for the transport of Layer 2 frames over an IP/MPLS network.

The benefits of having an option to configure pseudowire in a static SRv6 core plane gives businesses an edge over their competitors, as listed.

Enhanced flexibility: By using SRv6, service providers can define more granular and flexible paths for their pseudowires, improving network efficiency and performance.
Scalability: SRv6 allows for a scalable solution that can handle a large number of pseudowires without the need for complex BGP signaling protocols.
Interoperability: The feature is designed to work across various platforms and planes making it versatile for different network environments.

Configure Static SRv6 pseudo-wire

The purpose of this task is to configure static SRv6 pseudo-wires. To configure this, the network operators must define the local and remote SRv6 SIDs for the pseudo-wire endpoints. This involves specifying the segment routing configuration and ensuring that the pseudo-wire is correctly mapped to the desired network path.

Procedure

Define the locator.

Example:


Router(config)#segment-routing
Router(config-sr)#srv6
Router(config-srv6)#formats
Router(config-srv6-fmts)#format usid-f3216
Router(config-srv6-fmts)#usid local-id-block explicit start 0xee00 (default start is 0xfe00 - optional required if you if more than 256 )
Router(config-srv6-fmts)#exit

Router(config-srv6)#encapsulation
Router(config-srv6)#source-address 1::1
Router(config-srv6)traffic-class propagate

Router(config-srv6)#locators
Router(config-srv6-locators)#locator locator0
Router(config-srv6-locators)#micro-segment behavior unode psp-usd
Router(config-srv6-locators)#prefix fccc:cc00:1::/48

Define the Sub-interface.

Example:

	
interface Bundle-Ether101.40010001 l2transport
 encapsulation dot1q 1
 rewrite ingress tag pop 1 symmetric
!

Define the xconnect group.

Example:


Router(config)#l2vpn
Router(config-l2vpn)#xconnect group xg4001
Router(config-l2vpn-xc)#p2p vpws-400100150 
Router(config-l2vpn-xc-p2p)#interface Bundle-Ether101
Router(config-l2vpn-xc-p2p)#neighbor segment-routing srv6 static local fccc:cc00:1:ee96:: remote fccc:cc00:2:ee96::

Note

The remote fccc:cc00:2:ee96:: SID is the remote device SID. You must configure this on both ends of the PE. However the local and remote SIDs interrchange

Run the following show commands to view the defined locator, evpn, L2vpn, xconnect and evpn internal ID details.

Example:

Router#show segment-routing srv6 locator locator0 sid  fccc:cc00:1:ee01:: detail 

SID                         Behavior          Context                           Owner               State  RW
--------------------------  ----------------  --------------------------------  ------------------  -----  --
fccc:cc00:1:ee01::          uDX2              pw_id:3221225475                  l2vpn_srv6          InUse  Y 
  SID Function: 0xee01
  SID context: { static pw_id=3221225475 }
  Locator: 'locator0'
  Allocation type: Explicit
  Created: Dec 16 15:38:33.852 (00:05:19 ago)


Router# show evpn segment-routing srv6 detail 

Configured default locator: None
Configured default SID Function Length: 16 bits
EVIs with unknown locator config: 0
VPWS with unknown locator config: 0
Global SID Function Length: 16 bits
No SRv6 locators in use

Router#show l2vpn xconnect group xg4001 xc-name vpws-40010001 det

Group xg4001, XC vpws-40010001, state is up; Interworking none
Decoupled mode: Disabled
  AC: Bundle-Ether101.40010001, state is up
    Type VLAN; Num Ranges: 1
    Rewrite Tags: []
    VLAN ranges: [1, 1]
    MTU 9186; XC ID 0xc0000003; interworking none
    Statistics:
      packets: received 7109476, sent 5069183
      bytes: received 910012144, sent 648854934
      drops: illegal VLAN 0, illegal length 0
  PW: neighbor ::ffff:10.0.0.4, PW ID 2684354565, state is up
    PW class not set, XC ID 0xc0000003
    Encapsulation SRv6, protocol none
    PW type Ethernet, control word unknown, interworking none
    PW backup disable delay 0 sec

    Ignore MTU mismatch: Disabled
    Transmit MTU zero: Disabled
    Reachability: Up
    Nexthop type: Internal ID ::ffff:10.0.0.4

      SRv6              Local                        Remote                      
      ----------------  ---------------------------- --------------------------
      uDX2              fccc:cc00:1:ee01::           fccc:cc00:2:ee01::
      AC ID             0                            0                           
      MTU               9200                         9200                        
      Locator           locator0                     N/A                         
      Locator Resolved  Yes                          N/A                         
      SRv6 Headend      H.Encaps.L2.Red              N/A                         
    Statistics:
      packets: received 5069183, sent 7109476
      bytes: received 648854934, sent 910012144


Router#show evpn internal-id 
 
VPN-ID     Encap  Ethernet Segment Id         EtherTag     Internal ID
---------- ------ --------------------------- ----------   -----------
0          SRv6   fccc:cc00:2:ee01::          13421820     ::ffff:10.0.0.4
   Summary pathlist (ID 0x000000000000001a):
 0x05000005     fccc:cc00:2:ee01::                        fccc:cc00:2:ee01::                     

0          SRv6   fccc:cc00:2:ee02::          13421820     ::ffff:10.0.0.2
   Summary pathlist (ID 0x000000000000000a):
 0x05000002     fccc:cc00:2:ee02::                        fccc:cc00:2:ee02::


Router#show evpn internal-id  detail 

VPN-ID     Encap  Ethernet Segment Id         EtherTag     Internal ID
---------- ------ --------------------------- ----------   -----------
0          SRv6   fccc:cc00:2:ee01::          13421820     ::ffff:10.0.0.4
   Path resolved: TRUE
   Path Internal ID: ::ffff:10.0.0.4
    IP-Tunnel (ID:0x0000000000000019)
                fccc:cc00:2:ee01::                        fccc:cc00:2:ee01::                     
                  Path Version:1, Originating PE:::
   Summary pathlist (ID 0x000000000000001a):
 0x05000005     fccc:cc00:2:ee01::                        fccc:cc00:2:ee01::                     

0          SRv6   fccc:cc00:2:ee02::          13421820     ::ffff:10.0.0.2
   Path resolved: TRUE
   Path Internal ID: ::ffff:10.0.0.2
    IP-Tunnel (ID:0x0000000000000009)
                fccc:cc00:2:ee02::                        fccc:cc00:2:ee02::                     
                  Path Version:1, Originating PE:::
   Summary pathlist (ID 0x000000000000000a):
 0x05000002     fccc:cc00:2:ee02::                        fccc:cc00:2:ee02::

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