> 
> Something went wrong with one of my machines on campus.  It is using DHCP. 
> For some reason the name server stopped working for it, probably in March. 
> I tried to ping the name server and it didn't respond.  Another box in the 
> same room, which is static and not DHCP, continued to work as before.
> 

Mike, sounds like you do not have a veyr good handle on how the NICs are
handled in Linux, and I am sure using Ubuntu does not help you learn much
on that front... Type '/sbin/ifconfig' and see if the NIC has a live ethernet
on it, with an IP configured for it, a gateway, etc. That will tell you if
the DHCP is working or not. If not, try firing up the dhcp-client-daemon
(dhcpcd) over that NIC, typically "eht0" like this: 'dhcpcd eth0' and see
if you get it working. Chances are the dhcpcd is running, but you are not
getting a leased IP for some strange reason -- which may have to do with
some admin having blocked your machine, as you eluded.

You can always force the use of a particular nameserver by editing the
/etc/resolv.conf and adding something like:

nameserver 128.101.101.101

In the above example, I am pointing to a notorious UofM nameserver, which
may actually work pretty liberally for machines outside of the UofM.