Pseudowire Stitching

Pseudowire stitching is a technique where a pair of independent pseudowires are configured in such a way that they behave like a single point to point pseudowire. It is also called as multi-segment pseudowire (MS-PW).

Pseudowire stitching can be achieved using cross-connect.

Benefits of Pseudowire Stitching

Pseudowire stitching is useful in scenarios where a large network needs to be divided into small pieces, for example, core and metro side, each part of the network will be stitched to achieve end-to-end seamless connectivity.

Configuring Pseudowire Stitching

Below is an example with three nodes connected:

Router IDs are:

  • R1 - 1.1.1.1

  • R2 - 2.2.2.2

  • R3 - 3.3.3.3

Configuration on R1 node:

interface GigabitEthernet0/1/0
 no ip address
 negotiation auto
 service instance 1 ethernet
  encapsulation dot1q 1
  xconnect 2.2.2.2 100 encapsulation mpls
 !

Configuration on R2 node: (Stitching point)

l2vpn xconnect context PW
 member 1.1.1.1 100 encapsulation mpls
 member 3.3.3.3 100 encapsulation mpls

Configuration on R3 node:

interface GigabitEthernet0/1/0
 no ip address
 negotiation auto
 service instance 1 ethernet
  encapsulation dot1q 1
  xconnect 2.2.2.2 100 encapsulation mpls
 !

Verifying Pseudowire Stitching

R2#show mpls l2transport vc 

Local intf     Local circuit              Dest address    VC ID      Status
-------------  -------------------------- --------------- ---------- ----------
pw100010       3.3.3.3 100                1.1.1.1         100        UP        
pw100009       1.1.1.1 100                3.3.3.3         100        UP