[c-nsp] MPLS L2VPN Problem (Vlan Imposition)

kharananda at subisu.net.np kharananda at subisu.net.np
Sun Oct 5 07:19:59 EDT 2008


Dear All,

I have been trying to do MPLS L2VPN Over GRE for few days. It is
sub-interface(dot1Q) based l2vpn.

Below goes my Network senario.





  .....................                           .....................
  ...   VXR-7200-A ...       MPLS over GRE        ..  VXR-7200-B    ..
 .......................                         ....................


         ------------------------------------------------------
                             MPLS L2VPN Across


I am getting a weird problem. I can ping the VLAN network across MPLS
l2vpn  for about 5 to 7 minutes and it *stops automatically* and ever
comes up back.

Everything else seems OK. mpls ldp neighbor, mpls  forwarding database,
VCs status, GRE Tunnels, OSPF routes are all Ok even when i am unable to
ping vlan network(IPs) through l2vpn .


"Debug mpls l2trasport packets error" showed error report of  "ATOM-Eth
VLAN imposition: in Nu0, ciruit id 110 size 68 packet dropped, Fixup
failed". WHAT ACTUALLY IT IS ???

I am using Cisco IOS 12.4-2(T) on the VXR 7200 (NPE 300). Is there any BUG
for Cisco IOS i am using? If so, please suggest me the bug free IOS for
its
implamentation.

But this error report (Vlan Imposition) persists even when when I am able
to ping vlan across l2vpn (for 5 to 7 minutes)

My MPLS L2VPN is sub-interface (dot1Q on sub-interface) based.

Any help in this regards is highly appreciable.

Configuration details are given below

At VXR-7200-A

mpls ip
mpls label protocol ldp
mpls ldp router-id loopback 0

interface Loopback0
ip address 172.22.0.129 255.255.255.255
ip ospf 1 area 20
!
interface Tunnel0
description #### GRE Tunnel ####
ip address 172.22.15.129 255.255.255.252
ip ospf cost 100
ip ospf 1 area 20
mpls label protocol ldp
mpls ip
tunnel source FastEthernet1/0
tunnel destination 202.70.75.165

Interface fa 1/1.110
des ### Connected Cisco Switch trunk ###
encapsulation dot1q 110
mpls l2transport route 172.22.16.1 110


At VXR-7200-B

mpls ip
mpls label protocol ldp
mpls ldp router-id loopback 0

interface Loopback0
ip address 172.22.16.1 255.255.255.255
ip ospf 1 area 20
!
interface Tunnel0
description #### GRE Tunnel  ####
ip address 172.22.15.130 255.255.255.252
ip ospf cost 100
ip ospf 1 area 20
mpls label protocol ldp
mpls ip
tunnel source FastEthernet1/1
tunnel destination 202.70.77.14
!

interface FastEthernet1/0.110
des ### Connected To Cisco Switch trunk  ###
encapsulation dot1Q 90
mpls l2transport route 172.22.0.129 110


Regards,
Khara Nanda Luitel
Subisu Cable Net Pvt Ltd
Nepal.










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