add openssh root login troubleshooting (#36109)

* add openssh root login troubleshooting

* Update docs/pages/server-access/troubleshooting-server.mdx

Co-authored-by: Paul Gottschling <paul.gottschling@goteleport.com>

* Update docs/pages/server-access/troubleshooting-server.mdx

Co-authored-by: Paul Gottschling <paul.gottschling@goteleport.com>

* Update docs/pages/server-access/troubleshooting-server.mdx

Co-authored-by: Paul Gottschling <paul.gottschling@goteleport.com>

---------

Co-authored-by: Paul Gottschling <paul.gottschling@goteleport.com>

Author: GavinFrazar

docs/pages/server-access/troubleshooting-server.mdx

@@ -140,4 +140,17 @@ spec:
 ```
 
 For more information about moderated sessions and session sharing, see 
-[Moderated Sessions](../access-controls/guides/moderated-sessions.mdx).
+[Moderated Sessions](../access-controls/guides/moderated-sessions.mdx).
+
+## Unable to connect to agentless OpenSSH server as root
+
+You should check your sshd configuration in `/etc/ssh/sshd_config` for a setting like
+`PermitRootLogin no` or `PermitRootLogin forced-commands-only` - either of these
+settings will prevent login as root. 
+If you wish to log in as root to an OpenSSH server via Teleport, we recommend
+changing this setting to `PermitRootLogin prohibit-password`.
+
+You will need to restart sshd for the change to take effect:
+```code
+$ sudo systemctl restart sshd
+```