Telnet blocked on windows 2003,how to find the root cause and unblock?

I've already shut down the firewall.

Is there a way to check what is actually blocking telnet?

unknown

Posted 2010-01-27T05:40:59.497

Reputation:

Do you mean outgoing or incoming? Are there any error messages? Have you tried using Nmap on the port (default 23) to make sure it's open on the server? – amphetamachine – 2010-01-27T06:28:17.877

Yes,I can telnet the port from a remote machine. – None – 2010-01-27T06:34:31.903

Answers

if you have access to the destination server do the following, what results do you get on
netstat -an | findstr /i ":23"

if you get nothing then telnet is not running on the destination server.

if it is running and you have the firewall turned off then there is another firewall in place somewhere. Contact your network dudes to find out whats going on.

user33788

Posted 2010-01-27T05:40:59.497

Reputation: 478

thanks for the edit, port was wrong right? – user33788 – 2010-06-08T15:50:10.947

@smokenheap - ya, port 25 is SMTP – MDMarra – 2010-07-15T23:34:08.683

-1

Yes, you can check it.I have no idea have you tried network monitor before, it is a very useful tool for network troubleshooting.

John

Posted 2010-01-27T05:40:59.497

Reputation: 80

How can that tool check what is blocking telnet?Is there a screenshot for this? – None – 2010-01-27T07:37:00.887

Take wireshark for example, you need to capture the packets for several minutes when the problems appear,filter the unnecessary packets and diagnose it. – John – 2010-01-27T08:37:00.140

No,the problem here is that the telnet action itself is blocked,nothing about packets. – None – 2010-01-27T08:38:37.703

You can diagnose the application by packet sniffing.You can view the process and find out where it is blocked. – John – 2010-01-27T09:07:30.553

I can check the network information by netstat -ban,but it won't help me find where it is blocked.Could you upload a screenshot showing how it can be used to see what's doing the blocking job? – None – 2010-01-27T09:17:30.780

are you saying that you can't even run telnet? – user33788 – 2010-06-08T05:16:50.227