I have the same case, but what I want the network of router B to be totally anonymous for router A. I have tried to connect a cable between the 2 routers, where the caple end for router B goes to internet port, and to one of LAN ports for router A.
That didn't work unfortunately. Any Ideas? how to make pcs connected to router B anonymous for Router A? In other words, what I want is to have router A supplies Router B with net, without any control on router B pcs.