How Is a Routers Routing Table Updated?
Routing Tables Defined A routing table is a collection of information on where a network is located in reference to the router the table is in. Routers can have one or many ports, and each port can access many different networks. The routing table specifies on which port a packet is sent out based on the address the packet is for. All routing tables contain at least one entry known as the default gateway. The default gateway is where packets are sent if they are addressed to a network that the table has no route for. As an example, let’s say you have a router with the following entries in the routing table: network 192.168.1.0 is reached via port 1, network 192.168.2.0 is reached via port 2, network 192.168.3.0 is reached via port 3, and port 4 is the default gateway. If a packet is addressed to 192.168.3.1, the router checks the routing table to see what port network 192.168.3.0 is reached through. Since that network is reached through port 3, the packet is then sent out via port 3. A
