Routing Information Protocol (RIP)
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distance of 1, and RIP has an administrative distance of 120. I call RIP the
"gossip protocol" because it reminds me of junior high school, where if you
hear a rumor (advertised route), it must be true. That's how RIP behaves on an
internetwork--exactly like my 14-year-old son.
Verifying the RIP Routing Tables
Each routing table should now have the routers' directly connected routes as
well as RIP-injected routes received from neighbor routers.
This router output shows the contents of the 2621A routing table:
2621A#sh ip route
[output cut]
172.16.0.0/24 is subnetted, 5 subnets
R 172.16.50.0 [120/3] via 172.16.10.2, FastEthernet0/0
R 172.16.40.0 [120/2] via 172.16.10.2, FastEthernet0/0
R 172.16.30.0 [120/2] via 172.16.10.2, FastEthernet0/0
R 172.16.20.0 [120/1] via 172.16.10.2, FastEthernet0/0
C 172.16.10.0 is directly connected, FastEthernet0/0
2621A#
In this output, notice that the routing table has the same entries that the
routing tables had when you were using static routes. However, the R means
that the networks were added dynamically using the RIP routing protocol.
The [120/3] is the administrative distance of the route (120) along with the
number of hops to that remote network (3).
The next router output displays the routing table of the 2501A routers.
2501A#sh ip route
[output cut]
172.16.0.0/24 is subnetted, 5 subnets
R 172.16.50.0 [120/2] via 172.16.20.2, 00:00:11, Serial0
R 172.16.40.0 [120/1] via 172.16.20.2, 00:00:11, Serial0
R 172.16.30.0 [120/1] via 172.16.20.2, 00:00:11, Serial0
C 172.16.20.0 is directly connected, Serial0
C 172.16.10.0 is directly connected, Ethernet0
2501A#
Notice that in this output, the same networks are again in the routing
table, and you didn't have to add them there manually.
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