Highland Linux User Group

ufw is an excellence tool in linux servers

the first line of defense in your server is firewall, i used to play with iptables and it's a bit more work to do compare to ufw

to install ufw in Ubuntu:



start the firewall


that's it, you're now having ufw up and running

Usage:

Toggle logging

# ufw logging on|off

Set the default policy (ie “mostly open” vs “mostly closed”)

# ufw default allow|deny

Accept or drop incoming packets to (can see what services are available with ’status’ (see below)). can be specified via service name in /etc/services, ‘protocol:port’, or via package meta-data. ‘allow’ adds service entry to /etc/ufw/maps and ‘deny’ removes service entry from /etc/ufw/maps. Basic syntax:

# ufw allow|deny [service]

Display status of firewall and ports in the listening state, referencing /var/lib/ufw/maps. Numbers in parenthesis are not displayed to user

# ufw status

UFW Examples

Allow port 53

$ sudo ufw allow 53

Delete Allow port 53

$ sudo ufw delete allow 53

Allow port 80

$ sudo ufw allow 80/tcp

Delete Allow port 80

$ sudo ufw delete allow 80/tcp

Allow port smtp

$ sudo ufw allow smtp

Delete Allow port smtp

$ sudo ufw delete allow smtp

Allow fro Particular IP

$ sudo ufw allow from 192.168.254.254

Delete the above rule

$ sudo ufw delete allow from 192.168.254.254