[c-nsp] 3508 / GBIC ZX / Minimum IOS

[Deepak Jain]

> 
> According to Cisco, GigE has an autonegotiation procedure that is more 
> extensive than what is used for 10/100 Mbps Ethernet.
> This procedure negotiates flow control, duplex mode, and remote fault 
> information, so disabling it, may hide link drops and other physical 
> layer problems. Flow control & duplex can also be managed independently 
> (if allowed), so i guess remote fault information is the one that 
> actually matters.
> 

I think some of that is UDLD... UDLD is pretty good at determining 
various problems with the optical portion (layer 1) of the 
interconnect... but its limited by the optics you are using. The 3508 
doesn't support UDLD (to my knowledge) and ZX-GBICs from Cisco don't 
support much in the way of digital diagnostics.

We have had a number of interesting issues over the years that UDLD has 
both helped and confused on the 6500 platform.

All I can say (and I may be bitter) is that if autoneg on GigE was so 
grand... um... why has nearly every SP found reason to disable it?? And 
shouldn't auto neg (without neg on the other side) default to the same 
state on both sides?? -- you know, put the "auto" in "autoneg"??

Yup, old and bitter. Please excuse.

Deepak