[c-nsp] Possible split horizon issue with bgp signalled vpls

[Nick Ryce]

Hi,

I’m tearing my hair out with this one and can’t figure out how to resolve it.

I have 3 switches that have a BGP signalled VPLS with customer routers hanging off the end of all 3 ( one switch has 2 cpe )

All have the RD 56595:4 and RT 56595:4

All pseudo wires are up between the switches with config snippets below:-

Switch 1

VFI name: FLVPLS004, state: up, type: multipoint, signaling: BGP
  VPN ID: 4, VE-ID: 3, VE-SIZE: 10 
  RD: 56595:4, RT: 56595:4, 56595:4
  Bridge-Domain 903 attachment circuits:
    Vlan903  
  Neighbors connected via pseudowires:
  Interface          Peer Address    VE-ID  Local Label  Remote Label    S
  pseudowire100033   46.226.0.9      2      402          39              Y
  pseudowire100037   46.226.0.14     1      401          49              Y

This switch has 1 cpe with any vlan tags stripped and can ping all devices on the other switches


Switch 2

VFI name: FLVPLS004, state: up, type: multipoint, signaling: BGP
  VPN ID: 4, VE-ID: 1, VE-SIZE: 10 
  RD: 56595:4, RT: 56595:4, 56595:4
  Bridge-Domain 11 attachment circuits:
    Vlan11  
  Neighbors connected via pseudowires:
  Interface          Peer Address    VE-ID  Local Label  Remote Label    S
  pseudowire100015   46.226.0.12     3      49           401             Y
  pseudowire100018   46.226.0.9      2      48           37              Y

This switch has 2 cpe’s with any vlan tags stripped.  They can ping each other and the device connected to switch 1 but cannot ping device on switch 3

Switch 3

VFI name: FLVPLS004, state: up, type: multipoint, signaling: BGP
  VPN ID: 4, VE-ID: 2, VE-SIZE: 10 
  RD: 56595:4, RT: 56595:4, 56595:4
  Bridge-Domain 4 attachment circuits:
    Vlan4  
  Neighbors connected via pseudowires:
  Interface          Peer Address    VE-ID  Local Label  Remote Label    S
  pseudowire100028   46.226.0.12     3      39           402             Y
  pseudowire100027   46.226.0.14     1      37           28              Y

This switch has 1 cpe device connected with any vlan tags stripped and can only ping the device on switch 1


Each switch can see all the correct mac addresses.

It sounds like split horizon but I assumed this was only to do with the local switch?

All devices are running 15.3(3)S

Any help much appreciated.

Nick