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Mohanish_169493's avatar
Mohanish_169493
Icon for Nimbostratus rankNimbostratus
Sep 28, 2015

Unable to SSH BIG IP F5 GTM

Hi,

 

I have a F5 BIGIP GTM box.

 

I am able to access its GUI. However I am unable to access it via SSH Via doing a SSH via Putty just a black screen appears and nothing else happens. Please if someone can suggest any solution I have checked and my IP address is allowed in the Allowable IP's for SSH

 

17 Replies

  • Silly question, did you allow ssh to the user you're trying to use via the GUI? How far do you get into the SSH? does it instantly deny? or does it ask you for user information ?

     

    • Mohanish_169493's avatar
      Mohanish_169493
      Icon for Nimbostratus rankNimbostratus
      HI, I am not getting even a screen prompting for credentials. Its just a black screen that appears. I do not even get connection refused.
  • Hello, Mohanish

     

    • Does the connection successfully establish if you issue "telnet Your.SSH.mgmt.IP 22"? Are there any return messages such as "Connection Refused" or "Connection Timed Out"?

    One possibility is a crash of the SSH Daemon. You should try to restart the service with "bigstart restart sshd"; access your appliance Command Line either by using the physical serial connection cable, or try to access your device the via the AOM mgmt IP address (if you have configured it).

     

    For restarting BigIP daemons via GUI, follow the instructions here: https://support.f5.com/kb/en-us/solutions/public/13000/400/sol13444.html

     

    In the SOL article, scroll to: "Starting and stopping non-core daemons using the BIG-IP Configuration utility".

     

    • Mohanish_169493's avatar
      Mohanish_169493
      Icon for Nimbostratus rankNimbostratus
      hi, no I am not getting a connection refused or connection timed out. On SSH I just get a black screen. Can I restart the SSHD daemon via GUI
    • Hannes_Rapp_162's avatar
      Hannes_Rapp_162
      Icon for Nacreous rankNacreous
      Seems like you did not test with Telnet? The Telnet output would be more valuable from troubleshooting perspective than the "Putty black screen". But yes, I think you will be able to do it via GUI as well. I've updated my initial post with instructions.
  • Hello, Mohanish

     

    • Does the connection successfully establish if you issue "telnet Your.SSH.mgmt.IP 22"? Are there any return messages such as "Connection Refused" or "Connection Timed Out"?

    One possibility is a crash of the SSH Daemon. You should try to restart the service with "bigstart restart sshd"; access your appliance Command Line either by using the physical serial connection cable, or try to access your device the via the AOM mgmt IP address (if you have configured it).

     

    For restarting BigIP daemons via GUI, follow the instructions here: https://support.f5.com/kb/en-us/solutions/public/13000/400/sol13444.html

     

    In the SOL article, scroll to: "Starting and stopping non-core daemons using the BIG-IP Configuration utility".

     

    • Mohanish_169493's avatar
      Mohanish_169493
      Icon for Nimbostratus rankNimbostratus
      hi, no I am not getting a connection refused or connection timed out. On SSH I just get a black screen. Can I restart the SSHD daemon via GUI
    • Hannes_Rapp's avatar
      Hannes_Rapp
      Icon for Nimbostratus rankNimbostratus
      Seems like you did not test with Telnet? The Telnet output would be more valuable from troubleshooting perspective than the "Putty black screen". But yes, I think you will be able to do it via GUI as well. I've updated my initial post with instructions.
  • Have you confirmed you don't have a firewall in line preventing your port 22 connection?

     

    • Mohanish_169493's avatar
      Mohanish_169493
      Icon for Nimbostratus rankNimbostratus
      But had that been the case shouldnt I get a "Connection refused" or "Connection timed out" I am just getting a black screen on SSH thats it
    • Brad_Parker_139's avatar
      Brad_Parker_139
      Icon for Nacreous rankNacreous
      You can also test that the packets are getting to your management interface by using tcpdump. Something like "tcpdump -ni eth0 dst port 22 and src host ".
    • fanta_377379's avatar
      fanta_377379
      Icon for Nimbostratus rankNimbostratus

      You can restart SSHD through GUI. System--> Services-->check SSHD--> start.

       

      Thanks

       

      fanta

       

  • Have you confirmed you don't have a firewall in line preventing your port 22 connection?

     

    • Mohanish_169493's avatar
      Mohanish_169493
      Icon for Nimbostratus rankNimbostratus
      But had that been the case shouldnt I get a "Connection refused" or "Connection timed out" I am just getting a black screen on SSH thats it
    • Brad_Parker's avatar
      Brad_Parker
      Icon for Cirrus rankCirrus
      You can also test that the packets are getting to your management interface by using tcpdump. Something like "tcpdump -ni eth0 dst port 22 and src host ".
    • fanta_377379's avatar
      fanta_377379
      Icon for Nimbostratus rankNimbostratus

      You can restart SSHD through GUI. System--> Services-->check SSHD--> start.

       

      Thanks

       

      fanta