Ubuntu Dedicated Server SSH TimeOut Problem

PROBLEM:  Dialing into my dedicated Ubuntu server the connection drops if I am not active for a relatively short time of about 2 minutes.  

SOLUTION:  IMPLEMENTED:  Added the ServerAliveCountMax ServerAliveInterval entries to the client side ssh config file.

 

Solution 

• Client_loop: send disconnect: Broken pipe – Critical find 
• ssh -o TCPKeepAlive=yes -o ServerAliveCountMax=20 -o ServerAliveInterval=15 root@IP_address 
• This appears to imply the server has not been restarted when the restart and / or reload commands were issued. 
• Restart server and see if these statments are still required.  >  Updated and rebooted.  Still did not hold the connection longer than ~2 minutes.
• Checked server and client side config file and I do not see ServerAliveCountMax   ServerAliveInterval in either file
• Which side do the settings:  ServerAliveCountMax   ServerAliveInterval entries belong in?  Is it safe to assume in the SSH_Config files?
• Linux and VMWare: SSH avoid disconnection inactivity ( original in Spanish – link includes translation )  – see snippet below:  my guess appears to have been correct – add the entries to client side says this reference

From the SSH client side:

If the client is Linux:   Edit the configuration file:  ssh_config

• At user level: ~/.ssh/config
• or for all users: /etc/ssh/ssh_config

Add:

Host *
ServerAliveInterval XX
ServerAliveCountMax YY

 

Differences in names between server and client SSH configuration file names

• etc/ssh/sshd_config  is folder name on server
• etc/ssh/ssh_config on client

 

Research Links

• Goo: ubuntu ssh session times out
• How to Increase SSH Connection Timeout in Linux – this looked like it should do it but appears to have an error and or omission?    sshd.service not found
• Goo: ubuntu sshd service not found
• Unit sshd.service not found    –   suggests using:  systemctl restart ssh    – still timed out
• Goo: ubuntu ssh time out too short
• Ubuntu: ssh terminal always freezes after ~ 2minutes of inactivity –  says to modify same above values and also set  TCPKeepAlive yes
• tried systemctl restart ssh – again timed out
• How To Use SSH to Connect to a Remote Server -good overview.   Includes keys / ports.   It uses:  sudo systemctl reload ssh  for the reload but as noted that has not worked to date.  Covers all the features – using keys. 
• How to Fix “Connection Timed Out” in SSH – shows how to access the logs
• Ubuntu:  OpenSSH server
• Ubuntu: Installed SSH but no SSHD found – talks server and client version of OpenSSH
•  

 

Steps

1. Using vi  >  Set the values to:    ClientAliveInterval  1200   ClientAliveCountMax 3     
2. Saved using :wq 
3. Attempted to restart SSH using specified command:   systemctl reload sshd
4. comes back with   sshd.service not found
5. tried to restart using  systemctl reload ssh  – appeared to execute. Still timed out after this.

 

SSH Notes:

• What is sshd in Ubuntu?  sshd (OpenSSH Daemon) is the daemon program for ssh.     

vi editor notes

• Hit insert key to start writing over text
• type :wq   to write and quit.   

 

:wq

To save a file, you must first be in Command mode. Press Esc to enter Command mode, and then type :wq to write and quit the file. The other, quicker option is to use the keyboard shortcut ZZ to write and quit.