hold timer in rip

s.arunkumar · ‎12-18-2007

hi all,

Got a basic doubt..know lot of discussion has been happened for the same..still to get it cleared

1. What cause rip to enter in hold time,is it any received metric higher than one it have or only infinite metric for a route??

After RIP enters in hold time ,

2.What is the metric in routing table(or does it accept the new metric)??

3.What is the metric that it advertise to other routers??

4.Do it forward traffic during that time for that route??

regards

arun :)

bvsnarayana03 · ‎12-18-2007

1. RIP router enters holddown when the existing route in the routing table is unreachbale, & it receives an advertisement for same dest with higher metric. During the holdtime period if it doesnt recv any advertisement with lower metric, then rip accepts the route with higher metric & updates the table after holddown time expires.

2. However if a low metric route comes at time of holdtime, rip will accept the route & update the neighbors without waiting for the holddown timer to expire.

3. If a lower metric route is live, & rip recv a high metric route then it'll straight away reject the higher metric & continue to adv the lower metric route & thus no effect on traffic. But if the route is not reachable then traffic is not forwarded till it populates the table with new or better route.

hope that clarifies.

pls rate all helpful posts.

s.arunkumar · ‎12-18-2007

Thanks..

so u mean to say ,

For 1. It enters in hold time whenever any higher metric(including unreachable,ie 16) is recieved than the one it have.

For 2.It will accept that metric at the end of hold time only.

For 3.It will advertise the lower metric to neighbor not the higher metric it received.And if its unreachable then it will not advertise any updates for the route.

For 4. you didnt gave the answer...:)

i have still doubts as the link below says

hold time is the time during which routing information regarding better paths is suppressed.If better path is suppressed then i think point 3 above may not be correct.

http://www.cisco.com/univercd/cc/td/doc/product/software/ios124/124cr/hirp_r/rte_rih.htm#wp999690