Update SSH Port on Ubuntu 22.10 and later

update-ssh-port-ubuntu-22_10-and-later.md

Intro

SSHd now uses socket-based activation Ubuntu 22.10 or later. Below are 2 options to change the default SSH port.

A. Revert to service-based

1. Disable socket-based and enable service-based SSH

   systemctl disable --now ssh.socket
   systemctl enable --now ssh.service
   

2. Update the Port in /etc/ssh/sshd_config
3. Restart the SSH service

   sudo systemctl restart ssh.service
   

B. Socket-based

1. Create ssh socket dir

   mkdir -p /etc/systemd/system/ssh.socket.d
   

2. Create config

   cat >/etc/systemd/system/ssh.socket.d/listen.conf <<EOF
   [Socket]
   ListenStream=2022
   EOF
   

   This will make SSH listen on ports 2022 and 22. If you want SSH to only listen on port 2022, use the config below.

   cat >/etc/systemd/system/ssh.socket.d/listen.conf <<EOF
   [Socket]
   ListenStream=
   ListenStream=2022
   EOF
   

3. sudo systemctl daemon-reload

4. sudo systemctl restart ssh.socket

Refs:

• https://askubuntu.com/a/1439482
• https://discourse.ubuntu.com/t/sshd-now-uses-socket-based-activation-ubuntu-22-10-and-later/30189/9