Routers

What is a Router? A multi-port connectivity device Can connect different types of LANs as well as WANS Works at Layer 3 – Network Layer using logical addresses such as IP addresses Determines to which network the packet must be delivered based upon the final destination Determines the next hop based upon the final destination

Router Characteristics Routers talk with other routers Connects dissimilar networks They determine the shortest, fastest path between two nodes Reroute traffic if a primary path is down but another path is available Filers out broadcasts

Classification of Routers Interior router – directs data between nodes in a LAN Exterior router – directs data between nodes external to a LAN Gateway router – connects LAN to a WAN

Routing Tables Table stored in the router that tells where hosts are located and the best path to use to reach the host Static routing – network administrator configures a router to use specific paths Dynamic routing – routers automatically calculate the best path between two nodes