Am 21. Oct, 2024 schwätzte Keith Smith via PLUG-discuss so:

moin moin,

Here are a few directions to go that might help with troubleshooting.

You can use -v multiple times with the ssh client to get debug info.
Going to 3, -vvv, is usually sufficient to get to the point of final
rejection from the client's perspective.

You can change LogLevel on the server side as well, see man page for
sshd_config.

The new user exists on the destination machine? Has a functional home
directory?

Is there a reason you needed to add AllowUsers? Normally the default value
is to allow all users.

So ssh newuser@thebox gets you client_loop, but ssh ubuntu@thebox works?

It's Ubuntu 24.04, so systemd. Do you need to use journalctl to see logs?
Does your user have permission to see system logs?

----
        All users are granted access to their private per-user journals.
        However, by default, only root and users who are members of a few
        special groups are granted access to the system journal and the
        journals of other users. Members of the groups "systemd-journal",
        "adm", and "wheel" can read all journal files. Note that the two
latter
        groups traditionally have additional privileges specified by the
        distribution. Members of the "wheel" group can often perform
        administrative tasks.
----

ciao,

der.hans

> Hi,
>
> I am a little stuck.
>
> I am trying to configure a user that will allow me to log into an Ubuntu 
> 24.04lts server via SSH.
>
> I created a line : "AllowUsers default" in /etc/ssh/sshd_config
>
> Then sudo systemctl restart ssh
>
> Try to login and get "client_loop: send disconnect: Broken pipe"
>
> sudo tail /var/log/faillog returns nothing.
>
> I can SSH into the server from my Kubuntu desktop under the default user 
> created during server o/s install
>
> A search says it is probably a network issue.  Does not make sense given I 
> can SSH in using another user.
>
> Any thoughts are much appreciated.
>
> Keith
>
>
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