VPWS with BGP AD

Load vpws.w.bgp.ad.init.cfg

#IOS-XE (R1-R6, CE1,8)
config replace flash:vpws.w.bgp.ad.init.cfg

Configure a VPWS between CE1 and CE8. Use BGP for AD of the PEs. Do not manually specify the tLDP neighbor. BGP is already pre-configured in the core.

Answer

#R1
int Gi4
 no ip address
 service instance 1 eth
  encap default
!
l2vpn vfi context VPWS1
 vpn id 18
 autodiscovery bgp signaling ldp
!
bridge-domain 18
 member gi4 service-instance 1
 member vfi VPWS1
 no mac learning

#R6
int Gi6
 no ip address
 service instance 1 eth
  encap default
!
l2vpn vfi context VPWS1
 vpn id 18
 autodiscovery bgp signaling ldp
!
bridge-domain 18
 member gi6 service-instance 1
 member vfi VPWS1
 no mac learning

Explanation

We can implement VPWS using BGP AD as a sort of hack. We basically just implement VPLS, but only have two participating PEs. The PEs then place the AC and the VFI in a BD. I’m not aware of a way to signal an actual VPWS service using BGP AD (without EVPN of course).

In normal VPLS, we would do MAC learning, however in VPWS there is specifically no MAC learning. This allows VPWS to be more scalable, as it doesn’t consume CAM resources. We can simply turn MAC learning off under the BD to achieve the same functionality as VPWS. All frames received from the AC are just flooded out the VFI.