Network setup

YOu need only one thing on your network that has DHCP enabled. Every other switch or router should have it disabled. You setup should go:

Internet connection> Router (DHCP enabled) > To other computers and switches.

My network in my house is like this picture:

Assumptions:

• You are using home-class or consumer-grade gear. (i.e not enterprise routers)
• You want all your devices in one Class-C home Network. (i.e Same network ID for all devices )

Things You need to do:

1. Only ONE router may act as DHCP server.

2. Typically if you have one internet connection, Only ONE router will be your gateway to the internet and act as modem.

3. Remember to change the default IPs of each router so that they don't conflict on the network. (Most routers come with default IPs like 192.168.1.1 or 192.168.0.1. Keep your main router with that IP if you wish but change the IPs of the other routers to 192.168.1.x or 192.168.0.x. Additionally, add these manually-configured IPs as reserved IPs in the DHCP settings of your one and only router that acts as DHCP server)

4. As stated in your question, all routers and PCs are connected to a switch. Otherwise, you might need to pay attention to straight-through vs crossover wiring of the cables as router-to-router connections are a bit different. (Some old gear do not support auto-detection of cable alignment "crossover vs straight-through")

5. Typically, the above should work seamlessly. However, some old gear might still be a pain in the butt. If and only if you run into some problems or some PCs weren't "Seeing" the connection, you might need to enable RIP protocol so routers can exchange their routing tables and no forwarding problems occur. You do that by enabling the RIP protocol (Outgoing direction) on your one and only router that acts as internet gateway while enabling the same protocol in (Incoming direction) on your other routers.