Here's the scenario: My LAN has internet access via an RV-042 router; its LAN IP is 192.168.11.1, Mask 255.255.255.0. I have a WRT-54G wireless router connected to the LAN through the WAN port, configured as follows: WAN: IP: 192.168.11.2 Mask:255.255.255.252 LAN: 192.168.1.1 Mask: 255.255.255.0 No wireless encryption, i.e. for public access. The purpose of this configuration is to enable people connected to the wireless router access to the internet, but to prevent them from accessing my (private) LAN. THIS WORKS. My certified-up-the-ying-yang MCSE Instructor says that it shouldn't work because the two boxes are on different subnets, therefore different networks. I say that it should, because the two defined networks intersect: the wireless router can see the RV042, and sees it as its gateway to the internet; the RV042 can see the wireless router because its in its local subnet. If I'm wrong, why is this working? If I'm right, what do I tell my obnoxiously obstinate instructor to explain to him why he's wrong?