Adding a switch to virgin belkin 615 router
 

not sure if anyone else has come across this I am trying to add a switch to a belkin 615 router with any joy all the link lights come up but nothing, I did try a crossover cable but I must admit it was a little suspect but link lights came up, but then I have had this problem even with the old netgear router, this all use to work fine with my sky router , I have now bought a new switch and tried that and still no joy! any one know anything?