---Ubuntu14.04 firewall configuration of Linux learning article

Ubuntu14.04 firewall configuration

1. Installation:

Apt-get Install UFW

2. Enable:

UFW Enable

UFW default Deny

3. Turn ON/OFF:

UFW Allow 22/TCP allows all external IP access to the native 22/tcp (SSH) port

UFW deny 22/tcp Disable all external IP access to native 22/tcp (SSH) ports

UFW Delete Deny 22/tcp remove a rule from the firewall

4. Example:

1) View native firewall status:

2) Enable the firewall:

Because I am using the SSH connected server, so when I enable the firewall, the system asks whether to confirm this command operation, this command may disconnect the SSH connection.

3) Add rule:

Adding all external IPs can access 22 port rules per TCP protocol:

Then look at the system firewall state and you will find that the rule has been added:

Adding all external IPs can access 123 ports by TCP protocol:

Disable Port 123:

To remove the 123 port rule:

Allow this IP to access all of the native ports:

Delete the previous rule that you just added:

To disable the firewall:

---Ubuntu14.04 firewall configuration of Linux learning article