Ip Masq help needed!

The Coz · 11-15-2002, 01:10 PM

I recently setup my Desktop computer to Run Redhat 8.0, which installed flawless. Inside it i have two network cards. I also have a cable modem installed and a linksys router.

What im trying to do is run the internet connection from the cable modem to one of my network ports on the linux machine, and then from the second network port on the linux machine to the router, then route to the other computers in my home...the problem is that im having trouble setting that up.

Can anyone help??

peter_robb · 11-15-2002, 04:32 PM

The quick answer is...

echo 1 > /proc/sys/net/ipv4/ip_forward
iptables -t nat -I POSTROUTING -o eth~ -j MASQUERADE

where ~ is your cable modem eth device.
Make sure the router ip number and the Linux box number are in the same subnet, eg
192.168.0.1 & 192.168.0.2 Subnet 255.255.255.252
and the other side of the router is different, eg
192.168.1.~

That's the minimum, no security, no filtering or protection... to let people browse out.

See this masquerade HOWTO &tutorial for some extra guidance.

g0dzuki99 · 11-15-2002, 06:05 PM

You might want to check Firestarter (http://firestarter.sourceforge.net). It will set up NAT and firewall and has a gui interface.