How to change SSH port number on Ubuntu server

3 September 2010

Changing the port number of SSH daemon is a quick way of reducing the number of SSH brute force attacks your server might face (check the file /var/log/auth.log to see if there are many failed SSH login attempts).

Just to be on the safe side, create a backup copy of the SSH daemon config file.
```
sudo cp /etc/ssh/sshd_config /etc/ssh/sshd_config.vanilla
```
Edit the config file.
```
sudo vi /etc/ssh/sshd_config
```
Change the port number on the following line, e.g. to 2201 or some other unused port. Make sure you note down the port number.
```
Port 22
```
Restart the SSH daemon. You might get kicked out of your existing session.
```
sudo /etc/init.d/ssh restart
```
When you login next remember to include the correct port.
```
ssh youruser@yourserver -p 2201
```

administration
commandline
Linux
security
ssh
ubuntu