In the past, when I telnet into the DNS server, I type the username and password, then should get a list of files and I go from there to edit the files. Now, when I telnet to the server, I enter the username and password, receive a message of the last person to login and then no list of file names. I cannot use any commands. Please help, I do not know how or why this happened.

Can you please give a bit more detail?
When you login, do you get a command line
prompt? If so, you say you cannot run any
commands like "ls" even?

Are you the system administrator?
If not, you should contact the system
administrator.

I am the system admin at our facility but just know enough about the Unix DNS to get by. No, i do not get a command line prompt so the commands i type are not recognized, when I hit enter, it takes me to the next line w/o recognizing the command. All I get after logging in is the last login information and the cursor stops at the next line and just sits there. What could cause this symptom?

Is your home directory an NFS mount? This may cause your login to hang.

If this is the case, try an account that is local to the system.
If you don't have one, try to find out why NFS is hanging from a different system.

If you have a console terminal attached to the system, check to see if any error messages are coming up on it.