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

kharananda kharananda at subisu.net.np
Wed Oct 8 09:01:00 EDT 2008


Dear All,

I tried with many (Older/Newest) IOSes.  What I found is unless I do GRE 
there is no problem for MPLS L2VPN. It works absolutely fine until and 
unless I do GRE.
The moment I do GRE the error reports "ATOM-Eth VLAN imposition: in Nu0, 
circuit id 110, size 68, packet dropped, Fixup failed". I hope this 
could be fixed if I can tune some GRE parameters.

My GRE configuration is :

interface Tunnel0
description #### GRE Tunnel ####
ip address 172.22.15.129 255.255.255.252
keepalive 5
tunnel mode gre ip
tunnel source FastEthernet1/0
tunnel destination 202.70.75.165

Can you please help me on tunning some GRE parameters which could solve 
my problem.

Regards,
Khara Nanda Luitel.


kharananda at subisu.net.np wrote:
> 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.
>
>
>
>
>
>
>
>
> _______________________________________________
> Noc mailing list
> Noc at system.subisu.net.np
> https://lists.subisu.net.np/mailman/listinfo/noc
>
>
>   



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