SSH Client

• Check Client Version
• Client Usage
• Client Configuration

Check Client Version

$ ssh -V
OpenSSH_9.3p1, OpenSSL 3.0.8 7 Feb 2023

Client Usage

Standard usage is as follows:

$ ssh user@host

Where user is the username on the server, and host is the server ip address / domain name.

Other common options are as follows:

-i <key-file> tells ssh to use this private key for connection.

$ ssh root@172.21.0.142 -i ~/.ssh/id_ed25519

-L p1:d1:p2 maps the client machines p1 (port) to the d1 (hostname / ip) on p2 (port)

$ ssh root@172.21.0.142 -L 8080:172.21.0.142:8080

You can see more about tunneling here

Client Configuration

Config file usually belongs in ~/.ssh/config, if this file does not exist, create it.

This config lets you specify names for connections, working sort of like an address book, you can specify a new connection as follows:

Host test                  <-- name / matching pattern
   Hostname xxx.xxx.x.xxx  <-- your server ip
   Port 22                 <-- default is 22
   User root               <-- user to connect with
   IdentityFile ~/.ssh/xx  <-- the private key file

Then, when you want to ssh, you could type:

$ ssh test

This will connect to the test match in the config file above, with all the given options.

You can see all of the options here