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Running STP over EoMPLS


how can I run STP over an EoMPLS connection? Now we have two 7600 routers configured as PEs connecting to an MPLS backbone, and we'd like to bridge some of the VLANs on them between the two over an EoMPLS VC. I could configure the VCs but when I look to the spanning-tree topology it seems that the nw is partitioned between the two 7600s.

Is there anything else I have to specifically configure for STP to work over EoMPLS? The sw version we are running is 12.1(13)E4 both ends.




Re: Running STP over EoMPLS

This depends on what cards you are using. If you are using the 48 port RJ45 card then there might be a new software version which allows you to do dot1q tunnelling. I personally use the 16 port Gig card and hang of 3550s. On the 3550's you create the following on an interface port i.e. Fast E which connects your customer switch.

Int fast0/1

Swichport mode dot1qtunnel

l2protocol-tunnel cdp

l2protocol-tunnel stp

l2protocol-tunnel vtp

by issuing just l2protocol-tunnel on the interface enables all 3 by default. This works very well indeed all 3 protocol are tunneled within a dot1q trunk and your mpls core in the middle is completely transparent. We are just launching this service and most customers are amazed when all they see is really just an Ethernet cable which is 400 miles long. If you need any more help then email me on

BTW on my trials with the 7600 48 port RJ45 card you can configure these commands but they dont work. Hence the reason for using 3550's. Plus if you sot it out the 3550 route is a damn sight cheaper.

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