https://www.slackwiki.com/index.php?action=history&feed=atom&title=MasqueradeMasquerade - Revision history2026-04-08T16:08:53ZRevision history for this page on the wikiMediaWiki 1.40.0https://www.slackwiki.com/index.php?title=Masquerade&diff=133&oldid=prevErik: Copy from old2009-06-04T05:18:06Z<p>Copy from old</p>
<p><b>New page</b></p><div>Masquerading is what Windows calls "Internet Connection Sharing", although you can use it for sharing any network connection.<br />
<br />
This is just a basic script to give you the general idea, and to refine upon for yourself.<br />
<br />
#!/bin/sh<br />
# Define as appropriate for your setup<br />
# external interface (connected to the internet)<br />
EXT_IF=eth0<br />
# internal interface (connected to your local network)<br />
INT_IF=eth3<br />
# path to your iptables binary - leave this alone on slack<br />
IPTABLES=/usr/sbin/iptables<br />
# We don't want to just forward anything to anyone, or let everything<br />
# into our local network<br />
$IPTABLES -F FORWARD<br />
$IPTABLES -P FORWARD DROP<br />
$IPTABLES -A FORWARD -i $INT_IF -o $EXT_IF -j ACCEPT<br />
$IPTABLES -A FORWARD -i $EXT_IF -o $INT_IF -m state --state ESTABLISHED,RELATED -j ACCEPT<br />
# Do the actual masquerading<br />
$IPTABLES -t nat -F POSTROUTING<br />
$IPTABLES -t nat -A POSTROUTING -o $EXT_IF -j MASQUERADE<br />
# Enable IP packet forwarding<br />
echo 1 > /proc/sys/net/ipv4/ip_forward<br />
<br />
[[Category:Security]]</div>Erik