RIPv2 Broadcast updates
RIP version 1 always uses broadcasts. 255.255.255.255 That is expected behavior.
The updates aren't sent classless per se. They are sent without a
mask. The receiving side makes the assumption of the associated mask
based on the receiving interface. So RIPv1 can actually work in a
subnetted network assuming two things:
if we want to test this between R1 and R2 change the version of RIP and check the debug
R1# config t
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#router rip
R1(config-router)#version 1
R1(config-router)#exit
R1(config)#exit
R1#de
*Mar 2 21:29:31.232: %SYS-5-CONFIG_I: Configured from console by console
R1#deb ip rip
RIP protocol debugging is on
R1#
R1#
R1#
R1#
*Mar 2 21:29:37.016: RIP: sending v1 update to 255.255.255.255 via Loopback1 (1.1.1.1)
*Mar 2 21:29:37.020: RIP: build update entries
*Mar 2 21:29:37.020: subnet 1.1.0.0 metric 1
*Mar 2 21:29:37.024: subnet 1.1.2.0 metric 1
*Mar 2 21:29:37.024: subnet 1.1.3.0 metric 1
*Mar 2 21:29:37.024: network 2.0.0.0 metric 1
*Mar 2 21:29:37.028: network 3.0.0.0 metric 3
*Mar 2 21:29:37.032: network 4.0.0.0 metric 1
*Mar 2 21:29:37.032: network 12.0.0.0 metric 1
*Mar 2 21:29:37.036: network 14.0.0.0 metric 1
*Mar 2 21:29:37.036: network 23.0.0.0 metric 1
*Mar 2 21:29:37.040: network 34.0.0.0 metric 1
*Mar 2 21:29:37.040: network 172.16.0.0 metric 4
R1#
R1#
*Mar 2 21:29:37.336: RIP: ignored v2 packet from 14.1.1.2 (illegal version)
*Mar 2 21:29:37.456: RIP: sending v1 update to 255.255.255.255 via Serial0/0 (12.1.1.1)
*Mar 2 21:29:37.460: RIP: build update entries
*Mar 2 21:29:37.460: network 1.0.0.0 metric 1
*Mar 2 21:29:37.464: network 2.0.0.0 metric 1
*Mar 2 21:29:37.464: network 4.0.0.0 metric 1
*Mar 2 21:29:37.468: network 14.0.0.0 metric 1
*Mar 2 21:29:37.468: network 34.0.0.0 metric 1
*Mar 2 21:29:37.468: network 172.16.0.0 metric 4
R1#no deb ip rip
RIP protocol debugging is off
R1#
-===version 2
R1(config)#router rip
R1(config-router)#version 2
R1(config-router)#
*Mar 2 22:59:19.368: RIP: sending v2 update to 224.0.0.9 via Loopback10 (172.16.0.10)
*Mar 2 22:59:19.372: RIP: build update entries
*Mar 2 22:59:19.372: 1.1.0.0/24 via 0.0.0.0, metric 2, tag 0
*Mar 2 22:59:19.376: 1.1.1.0/24 via 0.0.0.0, metric 2, tag 0
*Mar 2 22:59:19.376: 1.1.2.0/24 via 0.0.0.0, metric 2, tag 0
*Mar 2 22:59:19.380: 1.1.3.0/24 via 0.0.0.0, metric 2, tag 0
*Mar 2 22:59:19.384: 2.2.4.0/24 via 0.0.0.0, metric 1, tag 0
*Mar 2 22:59:19.384: 2.2.5.0/24 via 0.0.0.0, metric 1, tag 0
*Mar 2 22:59:19.388: 2.2.6.0/24 via 0.0.0.0, metric 1, tag 0
*Mar 2 22:59:19.388: 2.2.7.0/24 via 0.0.0.0, metric 1, tag 0
*Mar 2 22:59:19.388: 3.3.8.0/24 via 0.0.0.0, metric 2, tag 0
*Mar 2 22:59:19.388: 3.3.9.0/24 via 0.0.0.0, metric 2, tag 0
*Mar 2 22:59:19.388: 3.3.10.0/24 via 0.0.0.0, metric 2, tag 0
*Mar 2 22:59:19.388: 3.3.11.0/24 via 0.0.0.0, metric 2, tag 0
*Mar 2 22:59:19.388: 4.4.12.0/24 via 0.0.0.0, metric 3, tag 0
*Mar 2 22:59:19.388: 4.4.13.0/24 via 0.0.0.0, metric 3, tag 0
*Mar 2 22:59:19.388: 4.4.14.0/24 via 0.0.0.0, metric 3, tag 0
*Mar 2 22:59:19.388: 4.4.15.0/24 via 0.0.0.0, metric 3, tag 0
*Mar 2 22:59:19.388: 12.1.1.0/24 via 0.0.0.0, metric 1, tag 0
*Mar 2 22:59:19.388: 14.1.1.0/24 via 0.0.0.0, metric 2, tag 0
*Mar 2 22:59:19.388: 23.1.1.0/24 via 0.0.0.0, metric 1, tag 0
*Mar 2 22:59:19.388: 34.1.1.0/24 via 0.0.0.0, metric 2, tag 0
*Mar 2 22:59:19.388: 172.16.0.20/32 via 0.0.0.0, metric 1, tag 0
*Mar 2 22:59:19.400: RIP: ignored v2 packet from 172.16.0.10 (sourced from one of our addresses)
R2#
*Mar 2 22:59:21.392: RIP: received packet with MD5 authentication
*Mar 2 22:59:21.396: RIP: received v2 update from 12.1.1.1 on Serial0/0
*Mar 2 22:59:21.400: 1.1.0.0/24 via 0.0.0.0 in 1 hops
*Mar 2 22:59:21.400: 1.1.1.0/24 via 0.0.0.0 in 1 hops
*Mar 2 22:59:21.404: 1.1.2.0/24 via 0.0.0.0 in 1 hops
*Mar 2 22:59:21.408: 1.1.3.0/24 via 0.0.0.0 in 1 hops
*Mar 2 22:59:21.408: 2.2.6.0/24 via 0.0.0.0 in 4 hops
*Mar 2 22:59:21.412: 4.4.12.0/24 via 0.0.0.0 in 2 hops
*Mar 2 22:59:21.412: 4.4.13.0/24 via 0.0.0.0 in 2 hops
*Mar 2 22:59:21.416: 4.4.14.0/24 via 0.0.0.0 in 2 hops
R2#
*Mar 2 22:59:21.420: 4.4.15.0/24 via 0.0.0.0 in 2 hops
*Mar 2 22:59:21.424: 14.1.1.0/24 via 0.0.0.0 in 1 hops
*Mar 2 22:59:21.424: 34.1.1.0/24 via 0.0.0.0 in 2 hops
*Mar 2 22:59:21.424: 172.16.0.10/32 via 0.0.0.0 in 4 hops
*Mar 2 22:59:21.424: 172.16.0.20/32 via 0.0.0.0 in 4 hops
R2#
R2#
