not sure about the gateway pointing to router address though
the ' gateway ' is your personal connection to the rest of the web ie router in your case. Some of these miners reqire your router to have all IPs assigned after it to be stuff like 192.168.1.(unit) where (unit) is the pc/miner/tablet's personally assigned id on your local network. Some routers allow you to ' always assign ' or ' reserve IP address ' for things like miners ( or if you have 1 web gaming pc, the one the world can attack since it is in the de-militarized zone and thus NEEDS to always have it's own IP). With that kind of setting, you can set the miner to think it has a static IP and the router to always assign that ip to it.
longer explanation than the previous, and hope it helps.