J-series and Cisco ME3400 L2 Issues

[bdfleming at kanren.net (Brad Fleming)]

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!
--
Brad Fleming
Network Engineer
Kansas Research and Education Network
Office:    785-856-9800 x.222
Moblie:  785-865-7231
NOC:     866-984-3662