[c-nsp] MPLS L2vpn problem (vlan impossition)

[kharananda]

Dear All,

I have been trying to do MPLS L2VPN Over GRE for few days. It is 
subinterface based l2vpn.

Below goes my Network senario.

                                       
-------------------------------------------------------------------
                                                                  OSPF 
Over GRE Tunnel
                  
.....................                                           
.....................                           
................................
              ...   VXR-7200-A       
......................................Cisco 2600     
............................. VXR-7200-B       ....
                 
.........................                                       
.......................                          
..............................
                       . dot1q    
-------------------------------------------------------------------- 
.dot1q    
                       . mpls l2transport route lo VXR -B 
                                                                 . mpls 
l2transport route  lo-VXR (route carried by OSPF Through Tunnel)
                       
.                                                                                                                     
.
                       
.                                                                                                                    
.
                       
.                                                                                                                    
. 
          
---------------                                                                                               
-----------------
         -   Cisco 2950    
-                                                                                           
- Cisco 2950    -
         
----------------                                                                                            
--------------------
                 
.                                                                                                                      
.
                 
.                                                                                                                      
.
             PC1(192.168.1.1/30)                                         
                                             PC2 (192.168.1.2/30) 
           


I am getting a weird problem.* *I can ping the VLAN network across  MPLS 
l2vpn i.e from PC1 to PC2  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 PCs.

I am using Cisco IOS 12.4-2(T) on the VXRs. Is there any BUG for Cisco 
IOS i am using. If so, please suggest me the bug free IOS for its 
implamentation.
                                               
'debug mpls l2trasport packets error' showed error report of  "*ATOM-Eth 
VLAN imposition: in Nu0, ciruit id 110 size 68 packet dropped, Fixup 
fauled*".
 But this report persists even when when i am able to ping PC1 to PC2 
(for 5 to 7 minutes)

My MPLS L2VPN is sub-interface based.

Any help in this regards  is highly appreciable.

_*Configuration detals.*_


*                                          _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 1/0
des ### Connected To Cisco 2600 ####
ip address 202.70.77.14 255.255.255.248

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

ip route 202.70.75.164 255.255.255.252 202.70.77.9
 
 

                         *_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 FastEthernet 1/1
 description **** Connected To Cisco 2600 ****
 ip address 202.70.75.165 255.255.255.248
 ip route-cache flow
 duplex full
 no cdp enable
!
!
interface FastEthernet1/0.110
des ### Connected To Cisco Switch Below ###
encapsulation dot1Q 90
mpls l2transport route 172.22.0.129 110

ip route 202.70.77.8 255.255.255.248  202.70.75.166


_*        At Cisco 2600       *_

interface FastEthernet 1/1
 description **** Connected To VXR-7200-A ****
 ip address 202.70.77.9 255.255.255.248

interface FastEthernet 0/0
 description **** Connected To VXR-7200-B ****
 ip address 202.70.75.166 255.255.255.252

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