One problematic machine running a Debian-based distro (ubuntu 9.10)
will answer to pings from other computers, but will not answer to
pings on 127.0.0.1 from itself. Likewise, it will not answer to pings
to localhost nor to its own IP address (pings to it's own IP address
are answered if I try from other machines, though). There is no
firewall installed on the machine and the /etc/hosts file has nothing
unusual. There is a Java program listening on port 8082, other than
that there is nothing unusual about this machine. What could be the
issue?