[c-nsp] Negotiation problem with Catalyst 2950 and Cisco 2821

[John Neiberger]

> I find it quite odd that as a service provider you would ever trust your
> network to autonegotiation.
>
> Hard code the port - leave nothing to chance. Is just one
> extra command, and you should be doing that after you label the port,
> with a description and putting it in a vlan, correct ?

We have the opposite philosophy. We set everything to auto. We have
*far* more problems with hard-set switch settings. It's been my
experience--and I have documentation at work to back this up--that
hard setting your devices to 100/Full is the worst possible choice.

The short story is that there is no standard method of behavior when a
NIC or switch port is hard set. Some devices still participate in Nway
autonegotiation even when hard set, while others completely disable
Nway. You run into problem when you connect devices that behave
differently. Some NICs that still participate in Nway will see that
there is no autonegiating link partner, so they'll try to be "helpful"
and fall back to half duplex under the assumption that they are not
connected to a device capable of full duplex.

I have successfully got Cisco to change their documentation to reflect
this behavior, but I don't have the link to that documentation here at
home. I'd have to go look for it.

John