Contact your system administrator. He's set things up wrong. If you are your system administrator then you've set things up wrong.
The error message looks pretty straight forward. You don't have
yppasswd running on dcsun2. It should be.
But doing a quick google search comes up with this result which indicates that you'll get this error if
yppasswd is running on both the client and the server. In this case turn it off on the client.
If you're stuck with csh as your login shell, you can still make it invoke bash when you log in. Put the following commands in your
~/.login (see also Changing the default shell without chsh or administrator priviledges):
if (-x /usr/local/bin/bash) then
exec /usr/local/bin/bash -l
/usr/local/bin/bash by the proper path if necessary. If everything works, remove
sleep 2 (which puts a delay during which you can press
Ctrl+C to drop to a csh prompt, in case something goes wrong).