topic Probelm with my Lan in Operating System - Linux

Probelm with my Lan

Kurupt — Thu, 04 Apr 2002 02:40:08 GMT

I am trying to set up a linux machine for a firewall for my LAN at home... I have two windows 2k pro machines and 1 linux 7.1 as my firewall computer to the internet.... I have it confugered like this......... 1)the linux machine is set up like this
-eth0
internet ip address 1XX.43.56.23 255.255.192.0
DHCP automatic from the ISP
-eth1
192.168.0.69 255.255.255.0
"It connects to the internet without a problem"
The windows machine is like this
WIN2k PRO machine configured like this
192.168.0.11 255.255.255.0
Gateway - 192.168.0.69
DNS - ISP Provider DNS Server
Everything seems to be connected all computerson my LAN can ping each other with a reply, including the linux machine.. BUT the windows machine cannot connect to the internet, i tryed to ping some ip addys of internet sites from the windows machine and i get a "request timeout" And when i try to ping www.yahoo.com or any site with the name i get "unknown host"
What configuration do ihave wrong, HELP PLEASE!!
Oh yah i have an ADSL connection to the internet!!! HELP!!!

Re: Probelm with my Lan

Ron Kinner — Thu, 04 Apr 2002 03:15:00 GMT

Your Linux box needs to do Network Address Translation (NAT) which is known as IP-Masquerade in Linux speak.

http://www.linuxdoc.org/HOWTO/IP-Masquerade-HOWTO/

It has to convert your 192.168 addresses to valid internet addresses. If it just passes the packets unchanged they aren't allowed to go on the internet and no one could get back to them anyway.

Ron

Re: Probelm with my Lan

Mark Fenton — Thu, 04 Apr 2002 22:17:43 GMT

If you are running iptables, there are several firewalling scripts out there that make the job pretty simple -- shorewall, bulldog, etc. Some with more features than others.

The scripts are useful if for nothing else than good examples of how to apply iptables commands.

Happy firewalling!