Cant connect through switch

[himpiano]

I have a cable modem that is connected to a 4 port switch upstairs that my 360 is hooked directly to, from that I have a cable that runs downstairs to a linksys wireless router so I can have wi-fi downstairs and then I have a pc hooked to that router directly so I can surf the web on my bedroom TV. Everything was working perfectly and we got a new cabinet to go upstairs to house all the equipment that was there. I unhooked everything and rehooked it all back up in the new cabinet and ever since when I hook the switch up the 360 works fine but I get no internet downstairs. I have run the line through the router and staright to the pc bypassing the router and get the same result. However, if I unhook the switch upstairs and hook the cable to the router downstairs directly to the modem everything downstairs works fine...but then I lose the connection for my 360. I could have possibly mixed up some of the cat5 cables when I was moving stuff around, does it make a difference if the cable is a crossover cable or not? I have checked all the cables currently hooked up and they look like they are all straight though cables...will this make a difference? Please help...

 

[False_Dmitry_II]

Wait, you had the modem connected to a switch first thing? Well, there's your problem. If nothing else, swap the places of the switch and router, and use the WAN port of the router to go to the cable modem. It should then all work fine. The way you have it now the router and the modem are trying to give DHCP addresses and there is no hierarchy. If you have to have the wireless where it is, disable ALL of it's router capabilities and have it basically just a switch with wireless. Then buy a cheap wired router and use that upstairs. Then the wired router is the main gateway. Anything connecting wirelessly will still get their addresses from the wired router anyway, and it should all work fine.