Problem with NIS-logins, RPC

[Stephan.Duehr@FernUni-Hagen.de (Stefan Duehr)]

I have collected some more information on our problem to post it again:

Problem: NIS-login, RPC
On prt-i3 we installed Debian 0.93

While booting, there is the following error message (3 times), and there
seems to be coherence with NFS mounts in /etc/fstab, because if I comment
them out, there are no errors. Manual mount works in any case without errors.
But now the error message:

clnttcp_create: RPC: Port mapper failure - RPC: Unable to receive

After booting, NIS-logins work fine, but after an indefinite time,
NIS-logins no longer work:

$ telnet prt-i3
Trying 132.176.1.66 ...
Connected to prt-i3.
Escape character is '^]'.
clnttcp_create: RPC: Program not registered
clnttcp_create: RPC: Program not registered
clnttcp_create: RPC: Program not registered
clnttcp_create: RPC: Program not registered
Debian GNU/Linux 0.93R6
Copyright (C) 1993, 1994, 1995 Debian Association, Inc. and others
 
prt-i3 login: duehr
clnttcp_create: RPC: Program not registered
Password: Connection closed by foreign host.

We have installed packages netbase version 1.22 and netstd version 1.25.