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
Software Requirements and Conventions Used
Category | Requirements, Conventions or Software Version Used |
---|---|
System | Installed Ubuntu 20.04 or upgraded Ubuntu 20.04 Focal Fossa |
Software | ufw >= 0.36 |
Other | Privileged access to your Linux system as root or via the sudo command. |
Conventions |
# – requires given linux commands to be executed with root privileges either directly as a root user or by use of sudo command$ – requires given linux commands to be executed as a regular non-privileged user |
Open ssh port 22 on Ubuntu 20.04 Focal Fossa Linux step by step instructions
- 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.
- 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
- 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)
- 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 theufw
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