Network Layer Reachability Information (NLRI)

Sanity checks

VALIDATE-UPDATE-SOURCE

To have the Cisco IOS software validate the source IP address of incoming routing updates for Routing Information Protocol (RIP) and Interior Gateway Routing Protocol (IGRP) routing protocols, use the validate-update-source command in router configuration mode. To disable this function, use the no form of this command.

Video Demonstration

R1	R2
router rip   version 2   no validate-update-source   network 172.1.0.0   network 192.168.1.0   network 192.168.2.0   no auto-summary	router rip   version 2   no validate-update-source   network 10.0.0.0   network 192.168.3.0   network 192.168.4.0   no auto-summary

Files:

GNS 3 Topology

R1.cfg
R2.cfg

NOTE: You need to add a static route in both routers pointing to each Fa0/0 IP for connectivity