Forum Discussion
Mohanish_169493
Nimbostratus
NimbostratusUnable 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
Brad_Parker_139Nacreous
Have you confirmed you don't have a firewall in line preventing your port 22 connection?
fanta_377379You can restart SSHD through GUI. System--> Services-->check SSHD--> start.
Thanks
fanta
- Brad_Parker_139You 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 ".
Mohanish_169493But 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_ParkerCirrus
Have you confirmed you don't have a firewall in line preventing your port 22 connection?
- fanta_377379
You can restart SSHD through GUI. System--> Services-->check SSHD--> start.
Thanks
fanta
- Brad_ParkerYou 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 ".
- Mohanish_169493But 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
- Hannes_Rapp_162
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".
- Hannes_Rapp_162Seems 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.
- Mohanish_169493hi, 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_RappHello, 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".
- Hannes_RappSeems 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.
- Mohanish_169493hi, 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
Jose2020_218280Silly 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_169493HI, I am not getting even a screen prompting for credentials. Its just a black screen that appears. I do not even get connection refused.
- Jose2020_218280We need more details.