what in the world?
okay, our cable company has a cable modem, the d-link router attaches to that via a cat 6/7 line...the d-link is the router the pc's and devices connect to.
Switches and hubs are generally slower. You should try to get a single router that can do what you need.
The two routers are gonna fight with each other if you just attache them at each end. Unless they automatically detect each other...Or you set one up as a repeater...basically a switch.
You have 4 ethernet ports at router A.
And another 4 at point B Going to 3 devices...
All of which can use the wifi supplied by both routers?
Run a line from port 1 router A - dlink to source port at router B- linksys...setup router B as a repeater using A's mac addy, because that connects to the isp.
This doubles the availability of wifi,Or adds wifi if the dlink doesnt have that. And puts 3-4 ports you can use at each end.
If you plan to lan party with xbox's or pc's or both...keep the hub near the devices with access directly to the router. You can then share from there.
switches and hubs can also hook up devices to each other. And share internet. It is also better to use it, In cases that would prevent having to run longer wires back to a router( the d-link and linksys)...Instead you run a shorter wire from xbox / pc2 to switch to pc1 with shared internet.
I'm not sure why you have a 5 port hub?