I am running a home network and I have just hit a bit of a bug that I need to have fixed. I just can't figure this out and I've stumped everyone I've asked.

My network configuration consist of 3 computers:
'bronson' a Redhat Linux 7.2 Router/Firewall
'hat' a Windows XP workstation
'frink' a Windows 98 workstation.

hat and frink are connected to a switch
the switch is connected to bronson
bronson is connected to my dsl modem

The problem is that frink can connect to anything outside of the LAN but it can't hit anything inside. Likewise nothing inside can hit frink. Not even the router.

If I 'arp -a' from hat I get an entry for bronson and frink but I still can't ping frink.

If I 'arp -a' from frink I get no entries.

If I run tcpdump on bronson I see packets coming in off the internet and going out from frink but that's it.

There is absolutely no communication between frink and any of the other PCs on the network (including the router) but for some reason frink can still reach the interweb.