topic Re: Could not connect to telnet session in Operating System - Linux

Could not connect to telnet session

Vipal — Thu, 18 Mar 2010 05:42:38 GMT

Hello Team,

I am trying to do TELNET Session with remote machine (linux based) by AIX Server.
When i use Telnet cmmd. it is just showing Trying.....

I have checked
a. Network issue... LAN Cable faulty found & replaced with new one.
b. checked telnet services & network services.
c. No issue found in remote machine i.e it is booting normally.

Ping command is running successfully from server to remote machine & vice versa.

We have installed one broadcast patch on remote machine..

Note----My remote machine confiugured in BASH SHELL prompt.

I tried netstat cmd on my remote machine, there is no output of cmd.

Is there any way to find out reason????

Re: Could not connect to telnet session

Steven Schweda — Thu, 18 Mar 2010 07:28:01 GMT

> I am trying to do TELNET Session with
> remote machine (linux based) by AIX Server.

So, you're sitting at an AIX system, and
you're trying to Telnet to a GNU/Linux
system?

uname -a # On both systems

> When i use Telnet cmmd. it is just showing
> Trying.....

My psychic powers are too weak to show me
your actual Telnet command. In it, did you
specify the name or the IP address of the
GNU/Linux system? What happens if you try
the other?

What are the IP addresses of these systems?

How many firewalls are there between them?

> I have checked
> [...]

How? Showing actual commands with their
actual output can be more helpful than vague
descriptions and interpretations.

> We have installed one broadcast patch on
> remote machine..

If I knew which version of which GNU/Linux
you were running on "remote machine", then I
might care which patch this might be, but,
again, I know too little even to care.

> I tried netstat cmd on my remote machine,
> there is no output of cmd.

Actual command? What, exactly, does "no
output" mean? Command hangs? Command runs
fine, but says nothing?

Can you Telnet from the GNU/Linux system to
itself? From the AIX system to itself?

> Is there any way to find out reason????

Not without some useful information.

Re: Could not connect to telnet session

Kapil Jha — Thu, 18 Mar 2010 08:12:32 GMT

if you able to ping, can you check your port is listening
telnet IP 23

if it says connection refused.you may have to check for port.

What about ssh, are you able to do ssh.

BR,
Kapil+

Re: Could not connect to telnet session

Steven Schweda — Thu, 18 Mar 2010 08:23:25 GMT

> telnet IP 23

Is this much different from, say,
"telnet IP"?

Re: Could not connect to telnet session

Ralph Grothe — Fri, 19 Mar 2010 09:55:07 GMT

> When i use Telnet cmmd. it is just showing Trying.....

This implies to me that your telnet packets never reach the remote Linux host,
either because of some routing issue, or because some firewall might drop packets to the telnet port.
Otherwise, if there was no telnet server running on the Linux host but the packets could get through you instantly would see a "Connection refused" (or similar wording) from your AIX telnet client.

Per default on most Linux distro installation these days there is no telnet server installed (because sshd offers a much securer alternative), and if though mostly some kerberized implementation.

So, are you sure there is a telnet server running?

Do you have other ways (like ssh) to connect to the Linux host?

Maybe the Linux host has loaded netfilter/iptables rules that drop packets to all ingress tcp port but a few like e.g. 22/tcp?

Re: Could not connect to telnet session

John Guster — Mon, 22 Mar 2010 15:19:12 GMT

try ssh to linux from aix. most linux does not have telnet enabled.