ssh connections stopped working

[Colin Law]

On 3 December 2010 19:39, David Fletcher <dave at thefletchers.net> wrote:
> This is driving me nuts!
>
> In my home network I have a server running Ubuntu Server, my own desktop
> and my son's desktop. Both desktops and my laptop are running Maverick.
>
> I just built him a new PC which we hoped to get set up tonight but I
> can't get the data off the HDD in his current one. I want to use rsync
> across the network to copy everything to a HDD in either my desktop or
> the server I don't care which, but it just won't go.
>
> I know for sure that rsync used to work with his machine because there
> is a previous backup on it that was done using rsync from my desktop to
> his.
>
> Tonight, I can ssh into the server no problem from my desktop, ping to
> his desktop works but ssh both to and from his desktop just fails and
> times out.
>
> Nobody has installed firewalls on anything, so I just don't know where
> to start.
>
> Curiously, I am sure the laptop also used to be able to ssh into the
> server via the WiFi but now does not. Same time out message.
>
> By switching some cables I have eliminated the possibility of the router
> blocking port 22.
>
> Can anybody give me a clue, please?

Is openssh-server installed?

Have a look in auth.log to see if anything is logged there when you
try to connect via ssh.  Are specifying a valid username to ssh when
you try to connect?
ssh -l username server

Colin