I have already found an answer how to connect two routers here. With the "same network" setup each device that tries to connect to the second router gets an IP address from the first. This is fine.
My question is, with this setup, is it still possible to block just the second routers IP (192.168.1.2 for example) and all the clients will be unable to connect? This is how I want it, but I am unsure if this is how it will work if I put them on the same network and disable DHCP on the second one.
Will I be able to block the second router and with that, all of its clients?