I'm not a networking wiz, but in our office the usual cause for slow
network response is exactly what you hit on in your message. When we
have had our Ethernet cards set to auto-negotiation, the card looks at
the network and seems to take the speed of the slowest network card,
usually an old router or hub somewhere. It often ends up being set to
10mbs Half-Duplex.

Try changing the card to 10_full_duplex or 100_full duplex.

smit devices
- Communications
- Ethernet
- Adapter
- Change/Show
Choose your adapter (ent0?)
Verify field called "Media Speed"

You may need to restart the network daemons (inetd, portmap, etc) to
get it to start using the new settings. Keep in mind that sometimes
changing these settings will stop your network connections from working.