|  | 1.3 | LAN Design
| 1.3.9 | Layer 3 router for segmentation
In implementations that have multiple physical networks, all data traffic from Network 1 destined for Network 2 has to go through the router. In this implementation there are 2 broadcast domains. Both networks will have unique Layer 3 IP Addressing Network/Subnetwork Addressing schemes. In a structured Layer 1 wiring scheme, multiple physical networks can be created very easily by simply patching the horizontal cabling and vertical cabling into the appropriate Layer 2 switch using patch cables. As you will see, this implementation provides for more robust network security. Traffic between the two networks can be controlled at the router. The router is also the central point in the LAN for traffic destined for the WAN port.