i hav one linux box connected to broadband havings ip's on eth0

ip - 172.31.1.138
netmask - 255.255.255.0
dns - 172.31.1.1
gateway-172.31.1.1


and on eth1 ip is 192.168.0.1
netmask 255.255.255.0
dns 172.31.1.1
gateway 172.31.1.1

eth1 is connected to local network through a switch or hub

client pc are having windows and linux installed in them coonected to the internet linux box through switch/hub.




i want to share the internet on all this pc's but be sure i am nt interested in squid proxy or any other proxies


i think it was donw through iptables masquerading and if not then plz also let me nw where exactly the iptable masquerading and nat works

Each box where the ip classes change between input and output NICs needs NAT.

You need static NAT as the ip numbers don't change, so use SNAT.

I suggest you have a good look at this iptables tutorial.