A routing table lists all of the preferred routes known to a router. It is viewable in two ways, one using the inspect tool of packet tracer and the other using the show ip route Cisco IOS command. With each way, you'll see a table with lots of columns and information. We are about to see what each of these means. Here is a sample output of a command used to show the routing table:

R1>show ip route
C    192.168.10.0/24 is directly connected, FastEthernet0/0
R    192.168.20.0/24 [120/1] via 192.168.10.1, 00:00:18, FastEthernet0/0
C    192.168.30.0/24 is directly connected, FastEthernet0/1
R    192.168.40.0/24 [120/1] via 192.168.30.2, 00:00:08, FastEthernet0/1

The first column denotes the routing protocol. The letter C is for connected and R is for RIP; if you check the routing table after configuring static routing, you'll find the letter S.

The next column is the destination network. After this, comes the administrative distance (AD)—the first number inside the square brackets; this specifies which routing protocol takes priority. The second number in the square brackets, after the slash, is the metric of this route. On RIP, the number of hops to reach a destination is used as the metric. RIP has an AD of 120 and static routing has 1.

So, if a router has two routes for the same destination network via both static routing and RIP, static routing will be used as it has a lower AD.

The IP address after via is the gateway's IP, also know as the next hop IP through which this route is reached. The time clock after that is called the Holddown timer. In any dynamic routing protocol, messages are sent at a certain interval (30 seconds in RIP). Each time a hello message is received, this timer is reset. If no response is received within 180 seconds this route is removed or an alternate route is found.

The final column is the outgoing interface to reach the gateway.