Hot Diggety! i love tsm was rumored to have written:
>
> The two 3584s that I run have both recently gone off the air,i.e I can't
> ping them.  They both have green link lights on the NIC. They are set to
> 100/Full  although I have tried Auto and 100/half.

3584 Operator Guide recommends they be set to 10/half (if hub) or 10/full
(if switch).

They do not work real well at 100 Mbps, and they haven't quite ironed out
the culprit despite multiple revisions of library firmware, from my
understanding. We have given up on ever getting it to work reliably at 100
Mbps. Seems fine at 10 Mbps, especially if the switch port is hardcoded to
match the 3584 enet settings exactly. Don't really trust autonegotiation.

IBM CE was here recently for a firmware upgrade and he had some internal
IBM documentation for himself (recently issued) that still advised if
Ethernet was hooked up, to set it to 10 Mbps only.

-Dan