In our company we have around 100 workstation with internet access, And day by day situation getting more worst and worst from perspective of using internet access for the purpose of doing private jobs, and wasting time on social sites.

Open hearted I am not for blocking sites like Facebook, Youtube, and others similar but day by day my colleagues do not finishing his tasks and while I looking at their monitor all time they are ruining IE or Mozilla and chat and things like that. In other way Ill like to block youtube sometime when We have very poor internet access speed,

Here is my questions: Do other companies blocking social sites ? Do I need dedicated device for that like hardware firewall, super expensive router Or I can do that whit my existing FreeBSD 6.1 self made router with two lan cards and configured nat to act like router.

I was trying do that using ipfw and routerfirewall but without success, My code looks like

ipfw add 25 deny tcp from 192.168.0.0/20 to www.facebook.com
ipfw add 25 deny udp from 192.168.0.0/20 to www.facebook.
ipfw add 25 deny tcp from 192.168.0.0/20 to www.dernek.
ipfw add 25 deny udp from 192.168.0.0/20 to www.dernek.
ipfw add 25 deny tcp from 192.168.0.0/20 to www.youtube.
ipfw add 25 deny udp from 192.168.0.0/20 to www.youtube.com