Ubuntu Firewall

Ubuntu includes ufw (uncomplicated firewall) by default, but it is not enabled.

Configure the Uncomplicated FireWall via CLI

#Install UFW
sudo su
apt-get install ufw

#SSH
ufw allow ssh

#FusionPBX
ufw allow 80/tcp
ufw allow 443/tcp

#FreeSWITCH - Sofia
ufw allow proto tcp from any to any port 5060:5069
ufw allow proto udp from any to any port 5060:5069
ufw allow 5080
ufw allow 5081
ufw allow proto udp from any to any port 16383:32768

#Enable UFW
ufw default deny
ufw enable
ufw logging on

Optional Ports

#OpenVPN
ufw allow 1194/udp
ufw allow 1194/tcp

#H323
ufw allow 1719/udp
ufw allow 1720/tcp

#STUN
ufw allow 3478/udp
ufw allow 3479/udp

#MLP protocol server 
ufw allow 5002/tcp

#Neighborhood service
ufw allow 5003/udp

Blacklist an IP address

ufw insert 1 deny from x.x.x.x

Additional Commands

ufw status
ufw delete 3

More Information

https://help.ubuntu.com/10.04/serverguide/C/firewall.html

http://pka.engr.ccny.cuny.edu/~jmao/node/28

https://help.ubuntu.com/community/UFW

man ufw