SSH Disconnects after a few seconds

**Ian_Chilvers** · April 29th, 2015

Hi,

I’ve just set up a new Ubuntu 14.04 server and whenever I SSH to it it disconnects me in seconds if inactive.

I’ve done all the changes below, and still it disconnects me. What have I missed.

In the /etc/ssh/ssh_config file I have the following

Code:

ServerAliveInterval 100

In the /etc/ssh/sshd_config file I have the following

Code:

ClientAliveInterval 600
TCPKeepAlive yes
ClientAliveCountMax 10

In the /etc/default/ssh I have changed the SSHD_OPTS to

Code:

SSHD_OPTS='-F /etc/ssh/sshd_config'

In the ~/.ssh/config file I have the following

Code:

Host *
ServerAliveInterval 100

What else do I need to change to stop SSH disconnecting me???

Many thanks in advance.

**tgalati4** · April 29th, 2015

First, check /var/log/auth.log for ssh-related errors. Post anything useful. Then comment out your changes and restart ssh or reboot. Also, ssh is a classic client/server application, so you need to look at both the client side and server side. It's possible there is a firewall or router policy that is blocking port 22 and it takes a few seconds to react.

**Ian_Chilvers** · April 30th, 2015

Hi

Looking at the auth.log sadly didn't give anything away. Results are below

Code:

Apr 30 16:50:22 test1 sshd[4179]: Accepted password for testuser from 10.10.10.10 port 43906 ssh2
Apr 30 16:50:22 test1 sshd[4179]: pam_unix(sshd:session): session opened for user testuser by (uid=0)
Apr 30 16:51:35 test1 sshd[4179]: pam_unix(sshd:session): session closed for user testuser

Now the SSH session seems to stop working after only 10sec of no typing. If you keep typing the session stays alive, but with no input or output after 10sec the session stops and a minute later in the auth.log the session is cleared out.

I've tried with or with my settings in place.
I've tried multiple VMs (Basic 14.04 setup with no options selected such as database, web, etc. Just a basic vanilla setup)
I've tried different SSH clients (Putty and also SSH Client from another ubuntu box)

Still the same results. After 10 seconds it timeouts and you lose the connection.

As for firewall. I'm running the SSH client on a Windows 8.1 connecting to an Ubuntu VM on the very same box using Bridge Mode. I've turned the Windows firewall off and still does it.

I don't experience these problems with older ubuntu's using the same SSH client and PC.

I'm clearly missing a setting somewhere but what????