I have my internet providers modem/router downstairs. Ethernet cable to a separate router upstairs.
I have an "internet" port on the upstairs router, but when I plug in the ethernet cable from the main router into it, it doesn't pass the internet through the other ethernet ports on it.
When I plug the main ethernet cable into port 1 instead of the one labeled "internet", it does pass internet to all the ethernet ports.
The way I see it, the "internet" port is the "in" and the other 4 ports are "out". Why does it work by using only the "out" ports? I'm probably misunderstanding something, but I would like to understand.