Iptables quick guide
From thelinuxwiki
http://www.linode.com/wiki/index.php/Netfilter_IPTables_Mini_Howto
Changing the default policy in iptables
iptables -P INPUT DROP
allow outbound rsync and insert rule at the top of the chain
iptables -I OUTPUT -p tcp -d 1.1.1.1 --dport 873 -j ACCEPT
NAT
show nat rules
iptables -L -t nat
hide nat behind and interface
iptables -t nat -A POSTROUTING -o tun0 -s 192.168.1.0/24 -j MASQUERADE
saving rules for reload on reboot
on fedora 17
iptables-save > /etc/sysconfig/iptables
