1 Modem, 1 Switch, 2 Routers - Question?


Jan 2, 2006
I have a question for anyone that might know if this setup will work. And I will attempt to keep this explanation extremely basic just to get to the point, but if any further details are needed just let me know.

My cable modem is plugged into my 8 port Netgear Switch.

Then 2 Linksys 4 port Routers are plugged into that switch.

One of these routers is both wirless and wired, and the other is just wired.

All computers that are connected wired, or wireless all have access to each other on the same shared router, and all have internet access.

But the computers that are on router a, can't see computers on router b.

I understand that is because that is just the way these routers work. But what I want to make happen is all computers, connected to router a & b , see each other on the same workgroup so I can use file sharing as I always have while just using a 4 port.

If anyone knows that this can be done with success, great!

If not let me know before I spend many more pointless hours trying.

Also for a little more background. My isp will only allow 3 connected devices to have an external IP address to the world.

So my modem, and the 2 routers take up the 3 available. I know I could fix this if I would just by a 8 port router and a wireless access point, but I want to "try" and make all this work with what I have.

Any help or insight will be greatly appreciated.




Sep 10, 2001
Question: Do you need two networks or will just one work?

It is possible in theory to do this but from what I am thinking it would require switches that support setting up a VLAN.

I have attempted this myself using router OS's such as BrazilFW and IPCop. I have found that even disabling NAT and setting static routes between the routers will not allow the two LAN side networks to communicate with each other. I have tried and tried to setup a simple VLAN using BrazilFW or IPCop in "router mode" and not "NAT mode" with little success. I may be missing something simple but I have spent hours trying to get this to work.


File and Printer sharing doesn't work between the two groups because although data passes through the originating computer's firewall just fine, it's blocked from entering the firewall of the computer in the other group. However, all clients can freely connect to the Internet as long as they initiate the data request, even through the request has to pass through two firewalls to get there.
If you only need one network, I would just simply disable DHCP and change the IP of one of the Linksys routers to make a simple wireless access point/switch.


Disable DHCP on one of the routers. Keep DHCP on the other. Both routers should have a static Internet IP address. Both should also have an external public IP address.

You'll want to run a crossover cable or an ethernet cable if both routers support auto-MDIx (won't need a crossover cable, switch ports adjust). Connect via the open switch port, not WAN port, on the routers.

On your computers that you want to use the router W/O DHCP configured, you'll want to set them up statically to go to the specific router without DHCP.

This should make your entire network available to each other because the routers will be connected together like switches internally. The router function on each should still work.

You could also download some form of software for Network Load Balancing which could do what you want.

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