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Home > Archive > CCNA > February 2001 > need for speed
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| Sea Dragon 2001-02-22, 2:42 pm |
| E.E question
Will the real distance vector characteristic that speeds up convergence please stand up?
Q 1.
You are the router administrator for your companies
Corporate interworks. You want to ensure that the WAN
Runs as efficiently as possible.
Which distance vector characteristic can help to speed up convergence?
1.Triggered updates
2.Split Horizon
3.Poision reverse
4.Ratt
5.Posion
6.Ratt Poision
Q2
Which distance vector characteristic helps speed up convergence?
1.Triggered updates
2.Route poisoning
3.Posion reverse
4.Holddown Timers | |
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| Hey Dragon,,,,cool pic,,, i just couldnt resist trying to answere this, I could be wrong.
Let me try my first answere to a question, anyone else feel free to answere for i am a beginner.
answere #2. I feel as though it is Route Poisoning with Poisen reverse. lemmel,pg 122.
Todd says that hold-downs use triggered updates which reset the hold-down timer to let neighboring routers know of a change in the network. triggered updates create a new routing table.
Holddowns prevent routes from changing too rapidly by allowing time for either the downed route to come back or the network to stabilize. hold-downs also tell routers to restrict for a specific time period as to prevent inoperative routers from being prematurely restored to other routing tables.
answere #1 I would say cut-through but, is that dist/vector???? seriously i would think split horizen would be just as I mentioned above.
anyone care to indulge about this???? | |
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| Sea Dragon
The real DV characteristic, in my opinion, is Triggered Updates. Why do I think that? Well, examine the options:
# Split horizon - this is where a learnt route is not propogated back through the same interface
#Poison Reverse - this where a router is marked as down
#Hold down timer - prevent regular updates from reinstating a route that has gone down
#Route poisoning - I've not heard of this
#Ratt, Ratt poison, and Poison are just funnies.
A DV routing protocol such as RIP, advertises its entire routing table every 30 seconds. Convergence, therefore would only happen after that update, unless something else triggers an update, ie Triggered Updates, which interupt the regular updates.
Did that make sense?
Hippo | |
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| Thanks Silk,
I agree with you Hip
Here are the answears,I picked triggered up dates on both, but I was wrong (according to the test) on Q#2,
Q1.Triggered update.Holddowns
Q2.Route Poisioning. Why? Because neighboring routers don't have to wait 30 sec(RIP)before advertizing the poisioned route.
Problem with DV
Counting to infinity, and loops
My question is which one speeds up convergence faster, I guess, there are many variables, but I believe that triggered updates/ hold down timers do the best job under most circumstances. A clue to this is within question #1 " you want the WAN to run as efficiently as possible" I will take it that triggered updates is best when dealing with speed.
?
sea out |
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