220 PART II Core Protocols Routing Table and Forwarding Table There are really two different types of network tables used in routers and hosts, and we'll distinguish them in this chapter. The routing table holds all of the infor- mation that a device knows about network addresses and interfaces, and is usually held in a fairly user-friendly format such as a standard set of tables or even a data- base, often with metrics (costs) associated with each route. A forwarding table, on the other hand, is usually a machine-coded internal one that contains the routes actually used by the device to reach destinations. In most cases, the routing one holds more information than is distilled in the forwarding table. ROUTERS AND ROUTING TABLES The router that attaches LAN1 to the world is CE0 , a Juniper Networks router. Let's look at the information in the routing table on CE0 .