I am running Mandrake 8.0 (KDE ver 2.1.1) on a machine with 2 NICs. This is a college project. I am attempting to configure this machine as a firewall, and to pass packets from one network to another. Eth0 is on my external network. Eth1 is on my internal network. I set the gateway in "netconf" to our school's router. My Eth0 is configured for the school's network (DHCP) and I can surf the internet with no problem.
Workstations on the internal network can ping both cards on my Mandrake machine, but CAN NOT go past ETH0!! I have downloaded several tutorials on ipchains and ip masquerading but none seem to be helping.

Please help!!

Hi,

Have you checked that ip forwarding is enabled? This can be checked by running the following command:

cat /proc/sys/net/ipv4/ip_forward

If the result is 0 then you need to run:
echo 1 >> /proc/sys/net/ipv4/ip_forward


You'll also need to check that ip masquerading is enabled via your ipchains/iptables firewall.

The following is a basic rule to enable ip masq, where 192.168.1.0/24 is the range of ip addresses on your lan.

ipchains -A forward -i eth1 -s 192.168.1.0/24 -j MASQ

You might find the following tutorials useful for configuring the rest of you firewall rules:

http://www.linuxplanet.com/linuxplan...orials/1241/1/

http://www.linuxplanet.com/linuxplan...orials/2100/1/


Hope this helps


Andy