I have a Linux box that is routing between two networks X.X.3.0 and X.X.4.0 , I want it to be able to connect these networks to the Internet.
I have read here on the @Kevin's great answer that in order to be able to do so i have to use NAT which means iptables, my server right now doesn't use iptables so I need to find the right command in order to enable that.
my network can be described like this:
Internet <-(eth0) Linux Router <-(eth1) 192.168.3.0 <--(eth2) 192.168.4.0
The eth2 is connected to the Router directly.
The two local networks can talk with each other, but no one can even ping to a public IP address. I have tried to sniff the packets in the Router, when i am issue the ping command to a public IP address on one machine in the .3.x network, but as far as i can tell there is a problem, and it seems to be with an endless ARP requests of the eth0 int about who has the 3.x IP address. It seems that i have to enable on the Router to behave like a NAT too. I have did a search and i couln't figure out the right command that i am need to issue with the iptables, although i have did try the commands that mentioned here and here. I have had to ability to route between the two local networks without using iptables at all, and since i am don't need it i prefer not to use it, unless it's impossibole to do NAT without it (in that case i am prefer iptable that any other program).
to sum up the question: 1. i need to be able that all the three networks would be able to talk to each other. 2. i prefer no use iptables (if that possibole) or any other added program. 3. That's all.