J-series and Cisco ME3400 L2 Issues

Hello all!

Recently, KanREN has begun purchasing Ethernet circuits from a new provider who uses a Cisco ME3400 for CPE to provide the link to us. We use primarly Juniper J-2320 and J-4350 routers for our site equipment (running JunOS 9.3 Enhanced Services).

We've seen a problem getting Layer2 to function correctly with various speed and duplex settings. We tried every combo of hardcoded settings on both sides but simply couldn't resolve some L2 errors and interface resets. In the end, we found a stable setup with the J-series set to auto/auto and the ME3400 set to 100/full.

Has anyone else seen similar problem using either the J-series or an ME3400? If so, did you ever find a complete resolution (or explanation)?

Thanks for any insight!


We never had the problem, but, today, Juniper release the 9.4 version of Junos software.

Maybe you can check the release notes to see if you find something related to.



What were the L2 errors? You might try asking your question on the
juniper-nsp [1] and cisco-nsp [2] lists.

[1] http://puck.nether.net/mailman/listinfo/juniper-nsp
[2] http://puck.nether.net/mailman/listinfo/cisco-nsp

In multi-vendor environment, being specific with L2 parameters saves a lot
troubleshooting hours and costly CSRs :wink: