Hi,
2 days back I faced a problem...
I wanted to start telnet on RHEL5 and SLES10SP1. But i was not able to.
It was giving error like illegal seek and was not allowing root to login and etc...
Most of the google result was saying that use SSH and not telnet... We know it but its an requirement to use telnet... So I am putting a summary how to debug the prob...

Debug telnet issue
1. Check out telnet server is running on DUT (i.e., the machine to which you want to telnet)
rpm -qa | grep telnet
If not, take rpm from net, install it and see.

2. If telnet-server is already there, see whether it is listening on correct port
netstat -tan
and there should be one entry like : tcp 0 0 0.0.0.0:23 0.0.0.0:* LISTEN

3. If it is not there, checkout
chkconfig --list telnet
It should show you telnet on

4. If not, run chkconfig xinetd on
reboot

5. If this is also fine. Edit file vi /etc/xinetd.d/telnet
and add a line disable = no

6. If it is there, then edit file vi /etc/securetty
and add entries like pts/0 and pts/1 and pts/2 and pts/3 .... etc
chmod 644 /etc/securetty

7. If this is also fine. Then add an entry of the telnet client to /etc/hosts file on telnet server.

The following are better ways to debug

1. Make sure telnetd is installed
rpm -qa |grep telnet-server

2. If it isn't installed install it.

3. After it is installed, see if it is running.
netstat -tl |grep telnet

4. If it isn't running see if you can start it:
sudo chkconfig telnet on
/etc/init.d/xinetd restart

The last two are fine.

8. If you still can't connect check your firewall settings.

HTH

Forrest

Check /etc/xinetd.conf and make sure you have correct "only_from = xx.xx.xx.xx"