How to open ssh port 22 on Ubuntu 20.04 Focal Fossa Linux

This short tutorial will explain how to open SSH port 22 on Ubuntu 20.04 Focal Fossa Linux.

In this tutorial you will learn:

• How to open ssh port 22
• How to remove ssh port firewall rule
• How to check current UFW rules for allowed/denied ports

Open and delete port 22 ssh rules on Ubuntu 20.04 Focal Fossa Linux with UFW

Software Requirements and Conventions Used

Open ssh port 22 on Ubuntu 20.04 Focal Fossa Linux step by step instructions

1. Check the status of your firewall.

   # ufw status verbose
   Status: active
   Logging: on (low)
   Default: deny (incoming), allow (outgoing), disabled (routed)
   New profiles: skip
   

   Based on the above output all incomming ports are blocked by default.

   ---

   ---

2. Allow the SSH port 22 by using the ufw command:

   $ sudo ufw allow ssh
   

   Alternatively, it is possible to allow only a specific IP address or network subnet to connect via SSH port 22. The bellow example will allow IP address 192.168.1.2 to connect via port 22:

   $ sudo ufw allow from 192.168.1.2 to any port ssh
   

   In this example to allow an entire network subnet 192.168.0.0/24 execute:

   $ sudo ufw allow from 192.168.0.0/24 to any port ssh
   

3. Check all currently defined UFW firewall rules:

   $ sudo ufw status verbose
   Status: active
   Logging: on (low)
   Default: deny (incoming), allow (outgoing), disabled (routed)
   New profiles: skip
   
   To                         Action      From
   --                         ------      ----
   22/tcp                     ALLOW IN    Anywhere                  
   22/tcp (v6)                ALLOW IN    Anywhere (v6)
   

4. To delete your SSH defined rules simply execute the same commands you used to allow SSH port 22 and specify the delete option right after the ufw command. Examples:

   $ sudo ufw delete allow ssh
   $ sudo ufw delete allow from 192.168.1.2 to any port ssh
   $ sudo ufw delete allow from 192.168.0.0/24 to any port ssh