Iptables block facebook

There are many “solutions” for blocking your company employees accessing Yahoo Messenger, hi5, Facebook or any other distracting services, but none of them is working properly.



So here is a perfect solution:


What you need:


- linux router for your network
- iptables firewall at least v1.3.7


Here are the rules:
Deny Yahoo Messenger packets:


iptables -I FORWARD -m string --string 'YMSG' --algo bm -j DROP
iptables -I FORWARD -m string --string 'messenger' --algo bm -j DROP
iptables -I FORWARD -m string --string 'meebo' --algo bm -j DROP
iptables -I FORWARD -m string --string 'buddy' --algo bm -j DROP
iptables -I FORWARD -m string --string 'webmessenger' --algo bm -j DROP
iptables -I FORWARD -m string --string 'web-messenger' --algo bm -j DROP


Deny facebook traffic rule:


iptables -I FORWARD -m string --string 'facebook' --algo bm -j DROP


Deny hi5 traffic rule:


iptables -I FORWARD -m string --string 'hi5' --algo bm -j DROP

and so on… you can modify these rules to fit your needs, you just need to edit the –string parameter


--string ''


Using this solution to filter specified traffic you don’t have to worry about port, protocol, application , source or destination.


Hope it helps someone.