hi,

About a week ago I upgraded my linode to ubuntu 14 lts. Everything has been working fine, today I went to ssh into the server and it was dropping the connection immediately.

running service ssh restart didn't resolve it.

things I have tried:-

* uninstalling/reinstalling openssh-server completely
* running a debug version and watching the authentication
* attempting to start it normally, and setting Loglevel DEBUG, and checking syslog/auth.log etc, no clues there either

/etc/init.d/ssh appears to do nothing. If I issue start/stop/restart/reload, it just executes silently with no feedback.

running sudo service ssh start outputs "ssh start/waiting", but provides no PID, it doesn't actually seem to launch a new ssh process.

just wasted 2 hours trying to get sshd back up and running and i'm all out of ideas

Hello,

Can you please provide us with the output of `netstat -plantu`?

You may be running into a network issue, a firewall issue (check iptables), or even an issue related to fail2ban (or similar). If you have set up fail2ban, iptables, UFW, denyhosts, etc you will want to make sure your IP isn't listed.

If `netstat -plantu` shows port 22 (SSH) open, then I would recommend looking into your firewall rules to ensure it's not related to firewall.

Also, you shouldn't use the direct `/etc/init.d` reference on Ubuntu 14.04. Instead, use `service`.

What does `service ssh status` give you? Does it say it's running? What about `ps -A | grep ssh`?

Thanks,

Dave.

It's possible that your existing sshd_config has something that the new version of ssh doesn't like. This should produce some sort of complaint in the logs. If so, you can try the following:

1. Make a copy of /etc/ssh/sshd_config and put it somewhere safe (like your home directory).

2. Completely remove sshd with apt-get purge openssh-server

3. Re-install sshd with apt-get update && apt-get install openssh-server

4. Make any configuration tweaks to /etc/ssh/sshd_config you wish, using the old sshd_config for reference.

5. Restart sshd with service sshd restart