According to different sources there're two opinions at how RIP uses holddown timer:
1. A router ignores ANY updates about failed network during holddown.
2. A router ignores only updates with worse metric than that it currently has.
What is right and what is wrong?
By the way, regarding second opinion: If a router had received poisoned route (with metric of 16), it starts holddown timer. So, what kind of updates that router ignores, if there's no metric worse than 16 (infinity)?
The way holddown works is that the router holds on to the route which it knows has failed, and remembers the old metric. It will ignore any updates with the same route and the same or worse metric until the holddown timer expires. The assumption is that if you receive an update with a worse, or the same, metric, it could be a "count to inifity" loop, and you need to break it.
We are pleased to announce availability of Beta software for 16.6.3.
16.6.3 will be the second rebuild on the 16.6 release train targeted
towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are
looking for early feedback from customers befor...
Introduction Featured Speakers Luis Espejel is the Telecommunications
Manager of IENova, an Oil & Gas company. Currently he works with Cisco
IOS® and Cisco IOS XE platforms, and NX to some extent. He has also
worked as a Senior Engineer with the Routing P...
In this session you can learn more about Layer 3 multicast and the best
practices to identify possible threats and take security measures. It
provides an overview of basic multicast, the best security practices for
use of this technology, and recommendati...