Situation:
1 Freesco router / firewall
1 Hub
6 XP / Win2k computers

All is fine, except several times a week the NIC's in the computers become unhinged. Looking at the event viewer the NIC shuts down and gets back up again after 30 minutes or so. This happens with all the computers at irregular intervals.

I suspect that the interval has something to do with the lease time on the IP address from the Freesco router, but why are the NICs failing?

Insight vastly appreciated.