Issue with 100 feet cable for internet?

[amitshahcorp]

I have wanted to set up a network such that a 100 feet cat 6a cable connects to my router to allow folks about 4 rooms away to connect seamlessly. The issue is that when this cable is plugged into the router, it does not seem to connect to the internet but when this same cable is transferred directly to the cable modem, it works fine. Please help as this is driving me a little crazy here. I plan to connect this long cable to another router in the future so that it can beam wirelessly to clients in rooms further down the block.