Route summarization with RIP
R1 is the Hub,
R2 and R3 are the Spokes.
R3 is connected to the following networks :
- 192.168.1.0/30
- 192.168.1.4/30
- 192.168.1.8/30
- 192.168.1.12/30
AND these networks are present in the
RIP Database through redistribution (redistribute connected route-map Connected->RIP).
On r1 :
r1#sh ip route rip
192.168.1.0/24 is variably subnetted, 5 subnets, 2 masks
R
192.168.1.8/30 [120/1] via 150.123.0.3, 00:00:27, Serial1/0.123
R
192.168.1.12/30 [120/1] via 150.123.0.3, 00:00:27, Serial1/0.123
R
192.168.1.0/30 [120/1] via 150.123.0.3, 00:00:27, Serial1/0.123
R
192.168.1.4/30 [120/1] via 150.123.0.3, 00:00:27, Serial1/0.123
150.123.0.0/24 is subnetted, 4 subnets
R
150.123.3.0 [120/1] via 150.123.0.3, 00:00:27, Serial1/0.123
R
150.123.2.0 [120/1] via 150.123.0.2, 00:00:04, Serial1/0.123
These routes can be summarized by
r3 using 192.168.1.0/26
On r3:
interface Serial1/0
ip address 150.123.0.3 255.255.255.0
ip rip authentication mode md5
ip rip authentication key-chain CCIEwannabe
encapsulation frame-relay
ip summary-address rip
192.168.1.0 255.255.255.192
serial restart-delay 0
frame-relay map ip 150.123.0.2 301
frame-relay map ip 150.123.0.1 301 broadcast
no frame-relay inverse-arp
no clns route-cache
end
On r2 :
r2#sh ip route rip
192.168.1.0/26 is subnetted, 1 subnets
R
192.168.1.0 [120/3] via 150.123.0.3, 00:00:04, Serial1/0
150.123.0.0/24 is subnetted, 4 subnets
R
150.123.1.0 [120/1] via 150.123.0.1, 00:00:04, Serial1/0
R
150.123.3.0 [120/2] via 150.123.0.3, 00:00:04, Serial1/0
Note that /30 subnets are no more
advertised.
