The objective of this article is to serve as a quick reference guide on how to allow incoming traffic on any TCP or UDP port using Ubuntu 20.04 Focal Fossa Linux with UFW firewall.
In this tutorial you will learn:
- How to open port to any source
- How to open port to specific IP address or subnet
- How to open UDP port
- How to open TCP
Example of how to Open/Allow incoming firewall port 53 on Ubuntu 20.04 Focal Fossa
Software Requirements and Conventions Used
| Category | Requirements, Conventions or Software Version Used |
|---|---|
| System | Installed or upgraded Ubuntu 20.04 Focal Fossa |
| Software | ufw |
| 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 |
How to Open/Allow incoming firewall port on Ubuntu 20.04 examples
- Open incoming TCP port 53 to any source IP address:
$ sudo ufw allow from any to any port 53 proto tcp
- Open incoming TCP port 443 to only specific source IP address eg. 10.1.1.222:
$ sudo ufw allow from 10.1.1.222 to any port 443 proto tcp
- Open incoming UDP port 53 to source subnet eg. 10.1.1.0/8:
$ sudo ufw allow from 10.1.1.0/8 to any port 53 proto udp
- Open incoming TCP ports 20 and 21 from any source, such as when running FTP server:
$ sudo ufw allow from any to any port 20,21 proto tcp
-
Open port for a specific webserver such as Apache or Nginx execute the bellow Linux command:
$ sudo ufw allow in "Apache Full" $ sudo ufw allow in "Nginx Full"
-
Open port for a specific service such as SSH:
$ sudo ufw allow in ssh