I am not much of a system administrator, so please be patient if this looks too simple for you.
I have a several computers at home, and all of them connect using an ADSL modem/router (and Wireless AP).
I have been attacked several times (mainly from Russia and Ukraine), so I thought I should have some kind of firewall, besides the ESET firewall on my Windows 7.
So now I have these (new) configuration: I have a small ADSL modem (Zyxel brand) which has only one Ethernet port. This modem is used to connect to internet and is configured in NAT mode. The interface has is configured with IP address 192.168.1.1.
I have an old PC and I have installed zentyal on it. It has two Ethernet ports, eth0 and eth1.
Eth0 is connected to the Zyxel modem with IP 192.168.1.2 and is checked as the WAN interface (external).
I have another ADSL modem which is also a router with 4 Ethernet ports and Wireless AP. One of the Ethernet ports is connected to eth1 on Zentyal box. The Ethernet port's IP is 192.168.2.1 and Zentyal's eth1 is 192.168.2.2.
Now, I want to enable other computers to connect to internet through the router both using Wireless and Ethernet.
The problem is that I don't know how to configure the router so it routes connections to the Zentyal box.
Does anyone have any clue? Again I am sorry if this looks stupid.