Iptables quick guide
From thelinuxwiki
http://www.linode.com/wiki/index.php/Netfilter_IPTables_Mini_Howto
Contents |
rule basics
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
allowing muliple ports
list of ports
iptables -A tableName -p tcp --match multiport --dports port1,port2,port3 -j ACCEPT
example
iptables -A INPUT -p tcp --match multiport --dports 22,80,443 -j ACCEPT
port range
iptables -A tableName -p tcp --match multiport --dports start_port:end_port -j ACCEPT
example
iptables -I OUTPUT -p tcp -d 1.1.1.1 --dport 1024:65535 -j ACCEPT
IP range example
iptables -A INPUT -p tcp --dport 22 -m iprange --src-range 192.168.1.100-192.168.1.200 -j ACCEPT
allow icmp echo-reply
iptables -A INPUT -p icmp --icmp-type echo-reply -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
destination NAT
iptables -t nat -A PREROUTING -d 1.1.1.10 -j DNAT --to-destination 192.168.1.228
saving rules for reload on reboot
on fedora 17
iptables-save > /etc/sysconfig/iptables
