A routing table is a database repository that holds the router's routing information that represents each
possible logical destination network that is known to the router. The entries for major networks are listed in
ascending order and, most commonly, within each major network the subnetworks are listed in descending
order. If the routing table entry points to an IP address, the router will perform a recursive lookup on that
next-hop address until the router finds an interface to use. The router will switch the packet to the outbound
interfaces buffer. The router will then determine the Layer 2 address that maps to the Layer 3 address. The
packet will then be encapsulated in a Layer 2 frame appropriate for the type of encapsulation used by the
outbound interface. The outbound interface will then place the packet on the medium and forward it to the
next hop. The packet will continue this process until it reaches its destination.
There are two ways in which a routing table can be populated: a route can be entered manually, this is called
static routing, or a router can dynamically learning a route. Once a router learns a route, it is added to its
route table.