How to listen on 2 or more ports for SSH daemon

SSH daemon (open SSH) can easily be configured to listen on 2 or more / multiple ports simultaneously.

To do so all you have to do is add another Port #### line in the configuration file.

For example:

Usually you will have something like this in your sshd_config file:

Port 22

Lets say you want to "also" listen on port 8822, so you should add:

Port 8822

the end result, you will have two lines of Port #### which will look like this:

Port 22

Port 8822

I have added as many as 3 ports, I am not sure what is the limit of how many ports you can listen to for SSH simultaneously.

Then you simply need to restart the SSH daemon by executing:

service ssh restart

or 

/etc/init.d/ssh restart

How to check to make sure it is working?

The easiest is just to try out if the new port is working. :-)

but you can also execute this statement in command line:

netstat -nap | grep ssh

You should see something like this:

tcp        0      0 0.0.0.0:58251           0.0.0.0:*               LISTEN      7977/sshd

tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      7977/sshd

tcp6       0      0 :::58251                :::*                    LISTEN      7977/sshd

tcp6       0      0 :::22                   :::*                    LISTEN      7977/sshd

The above output shows that server is listening for SSH on port 22 and 58251.