1. like all Asus mesh systems and routers from ASUS, the router has ASUSWRT as its operating system/firmware. ASUSWRT has convenient firewall configuration options (but is actually primarily software not hardware ;-) 2. 2x bundle consists of one XD4R and 1 XD4N model - The XD4R has two network ports and the XD4N has one network port - Mesh can be configured either by cable (preferred) or by WiFi as with all ASUS routers. The XD4R can be used as a router or access point and is usually the main device in the mesh network. The XD4N (or other Asus routers with AiMesh) can then be added as mesh satellites.