Need help with networking.

[DeezyAU]

I'm not very competent when it comes to networking so this may just be a trivial issue. Right now I have a modem and a wireless router with no WAN ports available for a power line connection as well (which I would like for lower latency gaming and in home streaming). Could I just buy a switch and have it between my wireless router and my modem and also have the power line coming out of the switch? If not how can I have both a wireless connection as well as power line without spending a lot of money for a wireless router with two WAN ports?

[Quiksilverpro]

I'm assuming you mean you have a wireless router that has no available LAN ports and you want to add an additional port so you can also run a powerline to your PC while maintaining a wireless connection? (WAN port is the incoming connection from the modem to the router, most  consumer routers only have 1 WAN port, but 4-5 LAN ports) is this correct?

[DeezyAU]

My wireless router has four LAN ports but I've tried them with multiple desktop PC's in my house and a couple of laptops, all with up to date drivers and the disk that came with the router has been successfully installed so yes I have LAN ports but they aren't working unless I missed something there. It doesn't come up with the LED indicating that something is plugged into the LAN ports and nothing changes on any of the PC's (no extra network options, no notifications, etc). I thought that LAN would work but I tried it and because it didn't work I assumed I needed WAN for the internet.

[Quiksilverpro]

Model of the router? and to answer your original question, you can't have a switch between the Modem and router, think of it like an umbrella (weird i know) but the internet is the rain, the umbrella (router) is able to channel and correctly manipulate your internet packets, therefore all devices that want to connect to the internet must be under that umbrella (connected to the main router). Putting a powerline connection in between Modem and router will cause issues with IP allocation because your PC and router would be competing for your external ip address which effectively disables both communications. As well as other issues such as DHCP settings, E.G: your PC doesn't default acquire the settings to directly communicate with your ISP. 

[DeezyAU]

I have a D-Link DIR-825. I have looked it up (not extensively) and I haven't seen anyone with the same issue unless they have done something to it such as 'flashing DD-WRT to it' or they have gotten the problem over time whereas I've never been able to have a wired connection with the LAN ports. Thanks for the explanation too as I said I don't really know what I'm doing in terms of networking and it's good to get a simple explanation.

[Quiksilverpro]

Ok, if you can access the router settings via the wireless then head over to the routers address (should be 192.168.0.1) then login, go to Advanced, then on the left-hand side go to Network Filter and just confirm that MAC filtering is turned off. If it is, then plug in a Computer to a LAN port on the router, allow at least 30 seconds after plugging it in for it to exchange setup information, then go to command prompt, and type in "Ipconfig /all" then look under the heading "Ethernet Adapter" to see if its got an IP address, if it hasnt then try pinging the router in command prompt " ping 192.168.0.1"

[DeezyAU]

Okay I've done all of that and it didn't work but changing the cable did... I guess the cable I've been using has been damaged or something. I'm really sorry I've been wasting your time I guess I thought it was so simple that I didn't try it or something. Seriously I'm sorry for wasting your time mate and thanks for the help anyway.

[Quiksilverpro]

Hey, if the problems resolved then it's never a waste of time. Have a good one