Hi Chris. A few thoughts.
First, I would strongly discourage you from using auto-negotiate on any network cards. It's a nice idea but (at least currently) an immature function. In auto-negotiate the network card tends to act like a MODEM when talking to the hub or switch and will often change speeds on the fly as it sees varying line conditions. You should really hard code your network card connection speed.
Additionally (but this is VERY important), DON'T forget to match the hub or switch port speed to the network card. This is essential for a stable connection. This could be part of the reason for the questionable performance that you've been getting. You will run (though poorly) with a card/port mis-match.
The command to change the adapter speed in the ODM ONLY (necessary if the adapter is in use .. the change will take effect on the next IPL) is:
chdev -l'entX' -a media_speed='Auto_Negotiation' -'P'
media_speed='100_Full_Duplex' -'P'
media_speed='Half_Duplex' -'P'
etc ...
Make sure you have the correct driver for that card. The command:
lslpp -l devices.pci.23100020.rte
will yield the installed level. For your level of AIX, 4.2.1.9 is the latest release.
For this particular issue I see NO reason what so ever to edit the ODM other that to say that you've done it.
I hope some of this helps. May the force be with you.
Geoff
ggoldman@ottaway.com