[c-nsp] WS-X6748-GE-TX auto negotiation anomalies

[Jason Lixfeld]

On an ME-3400EG-12CS, I can force the speed of a port to 10Mb and leave the duplex set for auto.  If I connect a 10/100 or 10/100/1000 device to this 10/Auto port, both ends negotiate to 10/Full Duplex.  The world is a happy place.  I can do the same thing on an ME-3400-24TS, a WS-X3550-24, a CISCO-7301, whatever.  The behaviour is exactly the same.

If I try to do the same on a WS-X6748-GE-TX, both ends negotiate to 10/Half.  It seems that the 6748 treats duplex negotiation differently than any other device; it doesn't de-couple speed and duplex negotiation.

Has anyone else seen this?  Any workaround?

Basically, if we sell a 10Mb port to a customer, we a) want to lock them down to 10Mb and b) don't want to have to educate  them on how to properly set duplex and/or troubleshoot duplex issues, so we leave everything set to auto.  This practice has worked out just fine for us, forever, as we've been using a combination ME-3400-24TS and WS-X3550-24 switches to terminate customers.  We made the assumption that the 6748 would behave the same as every other device out there, but we are running up against this issue while trying to migrate customers to this platform off of our standalone 1Us above.

'speed auto 10' would be an acceptable 6748 workaround, but even that behaves differently on the 6748 vs ME/3550.  The 6748 needs two speeds for speed auto ie:  speed auto 10 100 whereas the ME/3550 need only one ie: speed auto 10