change default Telnet port

2012-03-21

Question

_{Wednesday, March 21, 2012 4:00 AM}

In one of my Win 2008 R2 Server, I have activated Telnet Server service which is working OK.

Now I want to

1. create two new ports 14008 and 14009

2. change the default Telnet port to 14008

Thanks in advance

All replies (4)

_{Friday, March 23, 2012 3:09 AM ✅Answered}

Hello,

To open a port, refer to:

Open a port in Windows Firewall
http://windows.microsoft.com/en-US/windows7/Open-a-port-in-Windows-Firewall

After that, use the command netstat –an to view the opened ports.

You must specify the port with an integer smaller than 1,024. This is by design.

Refer to: To set the Telnet port on a computer running Telnet Server
http://technet.microsoft.com/en-us/library/cc772789(WS.10).aspx#BKMK_SETPORT

Here are some Telnet troubleshooting guidelines. Hope it can help.

Error Message: Error while connecting to the host - could not open a connection to host on port 23
http://technet.microsoft.com/en-us/library/cc754782(v=WS.10).aspx

Telnet Troubleshooting Guide
http://technet.microsoft.com/en-us/library/cc753360(v=ws.10).aspx

Thanks
Zhang

_{Wednesday, March 21, 2012 6:49 AM}

Can you please explain what you mean by your wanting to "create two new ports"?

All ports already exist. It is just a matter of weather or not any software is listening on those ports.

_{Wednesday, March 21, 2012 7:27 AM}

Hello,

You cannot CREATE ports but to listen on them. The default port for telnet is usually the port number 23. Use the following command to switch to another.

tlntadmn config port=port number

Please refer to the technet KB below.

Configure the TCP Port Number Used by Telnet Server
http://technet.microsoft.com/en-us/library/cc771200(v=WS.10).aspx

Thanks
Zhang

_{Wednesday, March 21, 2012 9:48 PM}

Sorry, I suppose to say " Open" rather then "Create" ports.

Question 1. Please tell me how to open these ports (14008 and 14009)

Question 2. I also like to telnet my server through 14008 port, not with the default port 23.

Anyway, when I try to config port 14008 as the telnet port, I get this error

C:\Windows\system32>tlntadmn config port=14008

Invalid value. Specify a positive number less than 1024 for Port option.

Question 3. Please explain the reason........

Then, to test, I specify port 1004, which was successful.

C:\Windows\system32>tlntadmn

The following are the settings on localhost

Alt Key Mapped to 'CTRL+A' :   YES
Idle session timeout        :   1 hours
Max connections             :   2
Telnet port                 :   1004
Max failed login attempts   :   3
End tasks on disconnect     :   YES
Mode of Operation           :   Console
Authentication Mechanism    :   NTLM, Password
Default Domain              :   xxxxxxx
State                       :   Running

But the trouble is: when I try to telnet that server with that port from client pc (XP), I get this error

C:\telnet 10.1.xx.xx:1004
Connecting To 10.1.xx.xx...Could not open connection to the host, on port 23: Co
nnect failed

Even, I can't see 1004 port is an open port from Client site, when I check it with "nmap"

C:\nmap 10.1.xx.xx

Starting Nmap 5.51 ( http://nmap.org ) at 2012-03-22 08:19 AUS Eastern Daylight
Time
Nmap scan report for 10.1.xx.xx
Host is up (0.00s latency).
Not shown: 993 closed ports
PORT      STATE SERVICE
135/tcp   open xxx
445/tcp   open xxx

1055/tcp open xxx

3389/tcp open xxx
5800/tcp open xxx
5900/tcp open xxx
16993/tcp open xxx

Question 4. What I have to do to make telnet work on that port.?

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