The question of what event can cause a RIP/IGRP hold-down timer to reset has been troubling me for sometime. Having researched this subject on the net, I have turned up different answers which has only confused me further. Two practice exams that I am using mention the following three valid reasons:
1. Hold-down timer expires
2. An update is received indicating the original route to the network has been restored.
3. The router receives a processing task proportional to the number of links in the internetwork. (this point has me completely puzzled)
But, a quote from Wendell Odom's Exam certification guide has this to say - "Hold-down timers can be reset when the timer expires, a routing update is received that has a better metric, or a routing update is received indicating that the original route to the network is valid."
About all I can safely deduce is that it resets when the hold-down timer expires and when the original route has been restored, but are there any other valid reasons? What's the definitive answer as far as the ccna exam is concerned?
I got the CCNA about 2 months ago.....
From what i've read I agree with wendell odom,
Hold-down timers can be reset when the timer expires, a routing update is received that has a better metric, or a routing update is received indicating that the original route to the network is valid. All three incidents can reset the timers.
My exam didn't include any timer questions but always remember that you are taking a Cisco exam and you must answer with the "Cisco point of view".
I hope I helped, good luck if u r taking the CCNA exam.
PS. This is my first post and this site is goooooood