IPTables Script
De WikiLICC
This script is used to configure iptables for DNAT and SNAT (destination/source network address translation). It's part of the NAT with IPTables page and explained there. This file should be saved to /etc/init.d/local
and symlinked to /etc/rcS.d/S39local
.
#!/bin/sh PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin NAME=local DESC="local services" # Replace this with your firewall's static IP EXTERNIP="X.X.X.X" # The IP address of the internal machine that will respond to SSH requests SSHHOST="192.168.1.200" # The IP range of the internal network LOCALNET="192.168.1.0/24" case "$1" in start) iptables -t nat -A POSTROUTING -d ! ${LOCALNET} -j SNAT --to ${EXTERNIP} iptables -t nat -A PREROUTING --dst ${EXTERNIP} -p tcp --dport 22 -j DNAT --to-destination ${SSHHOST} echo 1 > /proc/sys/net/ipv4/conf/all/forwarding ;; stop) echo 0 > /proc/sys/net/ipv4/conf/all/forwarding iptables -t nat -F ;; *) N=/etc/init.d/$NAME echo "Usage: $N {start|stop}" >&2 exit 1 ;; esac exit 0