Maximum Hop Count
Without checks in place, the wrong routing information can spread throughout the network. To prevent this, protocols such as RIP have a maximum hop count. For RIP this value is set to 15. Any route with more than the maximum hop count is deemed unreachable and will not be used. In the above scenario, the original hop count of 192.168.5.0/24 on RouterB was 2. After RouterA lost the connectivity and RouterC learned the wrong information, it would see 192.168.5.0/24 at 3 hop counts. When RouterB gets this update back from RouterC, it will add 1 to the hop count and make it 4. This cycle will go on. Without a maximum hop count in place, this will go on. This phenomenon is called counting to infinity. Without maximum hop count in place, the increasing hop count will cause the routes to be deemed unreachable, and will be removed from the routing table causing the loop to be resolved.