I know that this question has been asked like millions of times but all of them seem to be missing something. I think there is a big difference in how we think holddown timer should work and how it actually works.
So based on cisco's documentation:
But based on CCIE Routing and Switching Exam Certification Guide, 3rd Edition page 192:
"After the Invalid timer expires (180 seconds) for R1’s route to 172.31.103.0/24, R1 begins a
Holddown timer for the route. Holddown starts at (default) 180 seconds, and counts down."
and based on very extensive testing of the timers demonstrated by http://cisconinja.wordpress.com/2009/04/27/rip-timers/
" So what exactly causes holddown to occur? Earlier when we looked atthe invalid timer, we saw the route placed into holddown when theinvalid timer expired. As it turns out, this is the only time that the holddown timer is used."
I see the same results in lab as cisconinja blog post and the CCIE cert guide.
So my question is why does every other document on the web specify that holddown timer is started when a route of higher metric is received?
This is driving me a little crazy and I would like to get to the bottom of it.
Am I missing something?
Thank you in advance for you responses.