i neeeeeed help plzzzzzzz!!!

[Shadowtrooper]

hi all i am new with IP tables stuff and i have a problem....
i have a pc Contain a fedora OS and i want to make a small network (4 PCs Contain XP OS) and using the pc of fedora OS as a firewall
i want to Prevent the ping (i think it called(ICMP)) in the private network and prevent one of the PCs from Browsing internet(prevent port 80 and 81 as i think).
and i still don't know how to make the internet go Through firewall to the private network...

note: WAN = eth0
LAN = eth1
any one can help plzzzzzzz!!!!

[eyeoncomputers]

For blocking an IP from accessing a web server (assuming port 80) you can do

-A RH-Firewall-1-INPUT -p tcp -m tcp --dport 80 -s 192.168.111.111 -j REJECT

-s is for source host, and you can specify some ip address