Connecting Computers accross different subnets or IP addresses

I have a setup that involves:

• Cable modem/router at 192.168.10.1
• Wireless Router 1 at 192.168.20.1
• Wireless Router 2 at 192.168.30.1

The wireless router are connected to the Cable Modem via the WAN port. Singly they work great, but the problem occurs when trying to access a computer or resource that is located under a different router from another.

For an example, a computer connected on Wireless Router 1 can not access a computer connected on Wireless Router 2 or a Computer connected directly to the cable modem.

I want the IPs from 192.168.10.1 and 192.168.20.1 and 192.168.30.1 to all talk to each other.

I have read several posts and I think it has something to do with the routing table. Unfortunately, I tried many settings, and nothing seems to work.

I did not try any routing table modification on the cable modem as yet.

Please see my picture below as it has all of the settings I have set and will illustrate my issue better.

Here is the picture of the Network Setup and setting from the router

Thanks for your help.

Solution 1:

If I understand the question correctly, you have to connect the two routers to each other (eg LAN or wireless) and place them both in the same subnet.

In case you can put a small switch downstream of the cable modem, and connect both access points (putting them all in the subnet let's say 192.168.1.x/24).

It doesn't make much sense to have different subnets, especially without a "smart" switch (actually a real router) between them.

So you do not want to use the WAN port of the access points, but the LAN. Please be careful: disable all DHCP's except one

IPv4 routing essentially works in only two ways: if the destination IP is on the same subnet (obviously also considering the mask) the data is sent directly (via ethernet, wi-fi, whatever), or sented to the default router/ gateway that will "take care of it"