UFW - Uncomplicated Firewall
The default firewall configuration tool for Ubuntu is ufw. Developed to ease IP-tables firewall configuration, ufw provides a user-friendly way to create an IPv4 or IPv6 host-based firewall. By default UFW is disabled.
Step 1: Enabling / Disabling ufw
To enable it, you just need to type the following command at the terminal.
[root@localhost]# sudo ufw enable
Firewall is active and enabled on system startup
To disable it, just type.
[root@localhost]# sudo ufw disable
Step 2: List the current ufw rules
After the firewall is activated you can add your rules into it. If you want to see what are the default rules, you can type.
[root@localhost]# sudo ufw status verbose
sample output:
Status: active
Logging: on (low)
Default: deny (incoming), allow (outgoing)
New profiles: skip
Step 3: Adding specific rules to ufw
You can specify or add the port range which you want to setup with ufw.
[root@localhost]# sudo ufw allow /
Example: To allow incoming tcp and udp packet on port 22
[root@localhost]# sudo ufw allow 22
Example: To allow incoming tcp packets on port 22
[root@localhost]# sudo ufw allow 22/tcp
Example: To allow incoming udp packets on port 22
[root@localhost]# sudo ufw allow 22/udp
Thats it!!
