trouble with telnet

[Robert Prohaska]

What causes telnet and ftp to announce "connect...host is unreachable"?

An Asante ethernet card was installed without incident, and telnet
worked the first time it was tried but the session froze, forcing
a reboot.  Ping works on the local subnet reliably as does a loopback
test. Subsequent attempts to use telnet and ftp produce the "host
is unreachable" message.

Any ideas? 

bob prohaska