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New Member

Connectivity problems on ATM MPLS network

We have implemented a country wide MPLS network based on 8500 platforms. We have encountered some strange connectivity problems between some PE's. Without apparent reason connectivity is lost between some PEs and restored after some time. The global routing table is perfectly stable among all the routers on the path between respective PE's. Also the LVC's & TAGs are stable and practically we were unable to find any change between the working and not working state. As a curious thing, during the outage (minutes) clearing routes into a PE VRF was restoring connectivity on the respective VRF and all other VRFs on the respective PE also!

Has enyone seeing similar problems before?

PE routers are 3660 series and we've tried all IOS available on CCO.

5 REPLIES
New Member

Re: Connectivity problems on ATM MPLS network

I have not seen any issues like that before. It seems a little strange that clearing the routes brought back connection and that using different versions of the IOS did not help. If you find a solution to this problem let me know, as this is very interesting.

New Member

Re: Connectivity problems on ATM MPLS network

Thanks for your update.

We've escalated the problem to TAC and also no solution was found.

It looks that now the problem has dissapeared as the physical connections were changed. We have suspected a port/PAM into the 8540.

New Member

Re: Connectivity problems on ATM MPLS network

Have you made any provisioning (upgrading connectivity) bet the PEs and Ps....I suffer such a similar problem with our network PEs and I notice that this happen after provisioning links between our PEs (RPMs in MGX 8850) and the ATM LSR (BPX 8600).

when i issue "clear ip route vrf *" or reload the RPM.....all the VRFs operate normally again.....so I get used to such a problem after any network provisioning process but still i couldn't relate this to problems with VRFs.

New Member

Re: Connectivity problems on ATM MPLS network

We have an MPLS network with ATM MPLS core based on Cisco 8540 and Cisco 75xx and 72xx as PEs. Several times, we had a connectivity problem in the MPLS network - certain sites were not accessible from some points in the network. This often happens after a change in the MPLS (reload of ATM switch). To solve this a shut + no shut of tag-switching int helps. I suspect the 8540 switches. Has anyone seen this?

New Member

Re: Connectivity problems on ATM MPLS network

Well it looks we are on the same side of the problem at least! We were not able to isolate it in our MPLS network more than what was previously specified (TAC involved also).

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