Configure an alias for SSH

This is to instead type the following command in its full form:

~ » ssh axeldamian@qwertya.ath.cx -p 53000

just write the following:

~ » ssh alias

That’s creating an alias, a way to shorten the command

In the first command you connect to the host qwertya.ath.cx which is dynamic dns, through port 53000 of the router and with the user axeldamian

The connection is like this:

Client PC A (ssh server) → Internet → Router (port 53000) → PC B (port 22)

Your PC B doesn’t know, nor does it care, how the connection reaches it. All it knows is that it should listen on port 22, which is the standard for SSH.

The SSH alias configuration goes on PC A, the computer you want to connect from.

The SSH configuration file is used to configure the SSH client

~/.ssh/config

create the file if it is not created

It needs permissions that you can execute with the commands:

~ » sudo chmod 600 config

and

~ » sudo chown :USER ~/.ssh/config

In my case it is:

~ » sudo chown axelarrondo ~/.ssh/config

the content is:

Host alias 

HostName IP or host

User :your_user 

Port :router_port

In my case it is:

Host leibnixs 

HostName server-leibnix.dyndns.ws 

User axeldamian 

Port 53000

then you can connect:

~ » ssh alias

You may get the following errors if the permissions are incorrect:

In my case, leibnixs is ​​my chosen alias.