I'm working with a networked system that is configured as follows:
Local Network 1 on 192.168.0.x (this Network can access the Internet through a Gateway/Firewall/Router)
Local Network 2 on 10.10.0.x. (this Network is accessed through a router)
Both of these networks are actually running on the same physical network (the same ethernet cabling and all connected together through one unmanaged switch).
Computers A & B on Local Network 1 (with NIC IP's set to 192.168.0.x and NIC Gateways set to 192.168.0.1) can access the Internet through a Gateway/Firewall/Router (LAN IP set to 192.168.0.1 and WAN IP set by ISP (DHCP)).
Computers C & D on Local Network 2 can access another Private Network through a router (IP set to 10.10.0.1) with these computers' NIC IP's set to 10.10.0.x and NIC Gateways set to 10.10.x.1.
Now, I need the computers that are on Local Network 2 to be able to access both the private network on 10.10.x.x AND Local Network 1 (IP's 192.168.0.x).
I have considered several different ways of doing this, including using 2 NIC cards in each computer that needs access to all three networks (the Local Network 1, the Internet, and the Private Network). But, instead, I'm thinking of doing this:
Computers A & B are left alone, as they already have access to the Local Network 1 and the Internet, and they don't need anything else.
Basically, I do away with Local Network 2.
First, I set up the router into the Private Network with a LAN IP of 192.168.0.2, with NAT enabled and the WAN side set up for access into the 10.10.0.x Private Network. This will give me a gateway into the 10.10.0.x Private Network from my Local Network 1.
If I set the NIC IP of computers C & D to 192.168.0.x (instead of their current 10.10.0.x), and set the NIC Gateway on these computers C & D to 192.168.0.2 (the IP address of the router that connects into the Private Network), then these two computers can access both the Local Network 1 (192.168.0.x network) AND the Private Network (10.10.0.x). With this arrangement, these computers C & D can't access the Internet, though.
If I need computers C & D to access the Internet, as well as the Local Network 1 and the Private Network, then I can set the NIC IP's to 192.168.0.x, with the NIC Gateway IP's set to 192.168.0.1 (the IP of the Gateway into the Internet). This gives access to the Local Network 1 and the Internet. To get access into the Private Network, I can then set up a Route:
Route Add 10.10.0.x mask 255.255.255.0 192.168.0.2 metric 1
Of course, I would need to make this route persistent on a Windows 2000 or NT machine, and set up a .bat file to load on startup in a Windows 98 machine.
Does the above sound 'feasible'? Are there any possible problems that I might run into, using the above approach? Or would I be better off using 2 NIC cards in each machine (and if so, why?).
By the way, I don't think this is a 'difficult' issue for someone who knows a lot about networking, but it is VERY urgent that I get this resolved as quickly as possible and it is VERY important that it is done 'right' - so I'm giving it HIGH points. :-)
John
