I have USB rtl8150-based and PCMCIA ne2000-based NICs that I need to get running in linux. They both seem to hotplug properly, but don't function correctly under linux. When I ping 127.0.0.1 I get "Network is unreachable." Any ideas on what I can try to fix this? Thanks!

edit: BTW - I'm running sarge (debian)

Huh, that's weird. A couple basic commands would probably help you narrow the problem down:

ip route list - will show you the routing table. When working properly, it should have an entry:
127.0.0.0/8 dev lo scope link

ifconfig - like ipconfig for win32, only better. lists all the current active network interfaces, their ip addresses, etc. The loopback entry should be listed as "lo". If it's not there, you can try "ifconfig lo up", but it sounds like your problem might be a bit more serious.

Now, if you built your kernel yourself, you might have left out the option that would include the loopback device... which seems kinda strange, since I think you'd have to leave out the entire networking section. But I suppose it's possible.

I noticed two [failed] thingies during bootup - what's that command that displays the bootup output again? I'll post it for ya.

dmesg

[edit] ...although dmesg only shows messages up until the [ok] and [failed] start appearing. to get those too, you have to check the /var/log/syslog or /var/log/messages file.. or something nearby.