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  • Question

  • On our server 2008r2 servers, we cannot telnet to another 2008r2 server.  We can telnet from server 2003 to a 2008r2 server and we can also telnet from a server 2008r2 server to a 2003 server.  We tried to do a telnet localhost 25 and it says it could not open connection ot the host, on port 25: Connect failed.  Can anyone help me with this problem?

    Friday, February 7, 2014 1:45 PM

Answers

  • Hello,

    Can you please check if the server on which you are trying to telnet is having port 25 opened / or in listening mode?

    You can find which ports are in listening/established state by running netstat command

    For example if you can try telnet 3389 on localhost, it should work well and this is a remote desktop(RDP) port.

    Use netstat to find out if port 25 is listening on your localhost, below is one of the example. Replace 3389 with 25 port number in the below command and paste us the output.

    C:\Documents and Settings\admin>netstat -aon | findstr 3389
      TCP    0.0.0.0:3389           0.0.0.0:0              LISTENING       5272
      TCP    10.96.43.19:3389       129.39.244.70:34479    ESTABLISHED     5272


    Sincerely, Asifkhan -- Please mark my post helpful if it was really helpful to you.

    • Marked as answer by Quan Gu Monday, February 17, 2014 7:49 AM
    Friday, February 7, 2014 6:14 PM
  • Hi,

    the information you provide does not show that this machine is listening the port 25. If you do not have port 25, you cannot telnet localhost 25 successfully. it is normal.

    You should notice the windows Firewall, you can try to disable th firewall to see if it works.

    If you still do not open the proper port, we suggest you capture the packets to see what happened.

    Best Regards

    Quan Gu

    • Marked as answer by Quan Gu Monday, February 17, 2014 7:49 AM
    Monday, February 10, 2014 7:54 AM

All replies

  • Hello,

    Can you please check if the server on which you are trying to telnet is having port 25 opened / or in listening mode?

    You can find which ports are in listening/established state by running netstat command

    For example if you can try telnet 3389 on localhost, it should work well and this is a remote desktop(RDP) port.

    Use netstat to find out if port 25 is listening on your localhost, below is one of the example. Replace 3389 with 25 port number in the below command and paste us the output.

    C:\Documents and Settings\admin>netstat -aon | findstr 3389
      TCP    0.0.0.0:3389           0.0.0.0:0              LISTENING       5272
      TCP    10.96.43.19:3389       129.39.244.70:34479    ESTABLISHED     5272


    Sincerely, Asifkhan -- Please mark my post helpful if it was really helpful to you.

    • Marked as answer by Quan Gu Monday, February 17, 2014 7:49 AM
    Friday, February 7, 2014 6:14 PM
  • This is what it shows:

    TCP 10.10.1.33:52725 10.10.1.25:135 established 0

    TCP 10.10.1.33:52726 10.10.1.25:49155 established 724

    TCP 10.10.1.33:52735 10.10.1.25:49159 established 0

    TCP 10.10.1.33:52738 10.10.1.25:49159 established 724

    TCP 10.10.1.33:52739 10.10.1.25:49159 established 724

    TCP 10.10.1.33:52749 10.10.1.25:135 established 724

    TCP    127.0.0.1:1433   127.0.0.1:49250  established  2424

    TCP 127.0.0.1:1433 127.0.0.1:49251 established 2424

    udp  0.0.0.0:56725  *:*

    Friday, February 7, 2014 6:55 PM
  • Hi,

    the information you provide does not show that this machine is listening the port 25. If you do not have port 25, you cannot telnet localhost 25 successfully. it is normal.

    You should notice the windows Firewall, you can try to disable th firewall to see if it works.

    If you still do not open the proper port, we suggest you capture the packets to see what happened.

    Best Regards

    Quan Gu

    • Marked as answer by Quan Gu Monday, February 17, 2014 7:49 AM
    Monday, February 10, 2014 7:54 AM