ufw – Ucomplicated Firewall

I’m starting to play around with ufw (Ucomplicated Firewall), a firewall for Linux.

It’s command line based, but simple enough.

I’ll update this post as I play along.

Enable/disable ufw

sudo ufw enable
sudo ufw disable

Default policy

• mostly open ports

sudo ufw default allow

• mostly closed ports

sudo ufw default deny

Allow/deny services syntax

ufw allow|deny <service>

Add rules syntax

sudo ufw allow|deny [proto <protocol>] [from <address> [port
<port>]] [to <address> [port <port>]]

Delete rules syntax

sudo ufw delete <rule type> from <ip address> to any port <port
number>

Firewall status

sudo ufw status

Firewall loaded

To                         Action  From
--                         ------  ----
24800:tcp                  ALLOW   100.000.1.1

Examples

sudo ufw allow proto tcp from 100.000.1.1 to any port 24800
sudo ufw delete allow proto tcp from 100.000.1.1 to any port 24800
sudo ufw allow ssh
sudo ufw delete allow ssh

Further reading

• Ubuntu Wiki
• Ubuntu Forums

last updated: 11-06-2008

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