Canadian Router and American Router sharing one modem - how can this work?

Jake_141

Prominent
May 15, 2017
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Hello!

I have two routers on my network - the first called "The American" is using a dd-wrt flashed router at 192.168.2.1 and is plugged directly into the cable modem. The second called "The Canadian" is a non flashed netgear router at 192.168.1.1 plugged directly into the modem as well. Devices that need an American IP should connect to the "American" router, and devices that need a Canadian IP should connect to the "Canadian" router. This is working well, however there are times when devices on the Canadian network need to talk to devices on the American network. I plugged a cable in from the LAN on the Canadian router to the LAN on the American router and sure enough the devices could talk to each other. However I now notice that devices connecting to the Canadian router have the American IP and vice versa. How can I sop this from happening and what would be the optimal settings for the network I have?
 
Solution
I am surprised you got them both to work on the modem most times the ISP limits you to a single router/ip address.

There is no easy way to fix this because you now only have a single lan and the DHCP does not know. If you can flash the other router to dd-wrt you could then connect them together with a third network and then actually route between them. You could also use 1 lan/subnet and then manually configure the ip addresses and gateway to use the secondary rotuer.
I am surprised you got them both to work on the modem most times the ISP limits you to a single router/ip address.

There is no easy way to fix this because you now only have a single lan and the DHCP does not know. If you can flash the other router to dd-wrt you could then connect them together with a third network and then actually route between them. You could also use 1 lan/subnet and then manually configure the ip addresses and gateway to use the secondary rotuer.
 
Solution