disctance vector protocols

alimoe

Distance vector protocols learn routes by transmitting updates... T or F

I thought it was true.... but I was wrong... It was false.. Now in order a one router to obtain information from a remote router it must recieve updates, so how is that false. Can someone help??

seth223uk

distance vector pass on periodic updates to neighbouring routers and learn routes via the updates where all or part of the routing table for the particular protocol is passed to a neighbour. The information contained in the updates is subject to questioning as distance vector routing works on rumour from neighbours thats why we have split horizon and route poisoning and holddown to improve the reliability of path determination and hopefully form a well converged internetwork.

To understand these concepts you should take alook at wendell odoms cisco press book for 607 or the sybex book, the chapter on routing protocols

distance vector do send updates to neighbouring routers so it is true but id have to see the question in context to answer, was the question from a reliable source or just on the net somewhere?

Webmaster

Distance vector protocols learn routes by transmitting updates

All routing protocols learn routers by transmitting updates....that is why routing protocols exist.

A primary difference is that Distance vector protocols broadcast there entire routing table (routing updates) to all routers... (which can infact be considered neighbors because broadcasts don't pass a router.) ... on a periodic basis... (e.g. every 60 seconds.)... by default. (IGRP and RIP can be configured for triggered updates)

Link-state protocols multicast partial updates only to routers with which they established a neighbor relationship (typically using HELLO packets) and only when needed. (the latter is not entirely true, there are always exceptions, but for the definition of link-state protocols it is correct;) )

Check out the last couple of posts of the CCNA TechNotes topic in this forum for more info.

DuoMaxwell

The correct answer is false!
DVP doesn't transmit to learn.
They receive routing updates to learn.
Tricky eh?
It's in the Q&A of the CCNA Exam guide under routing.

seth223uk

i hate cisco for them trick questions, the answer is false i neva read the question properly! Take note to read the questions thoroughly as there are so many trick questions in the exam, if you can spot them then ull be fine

Webmaster

Actually... then it should be "DVP router" learns routes from receiving updates (all routers do...)

alimoe

Some of the questions are very tricky and they can throw you off. But with distance vector protcols regarding that question... Like I mentioned before.. I am aware that a router recieves update but at the same time they do also send updates to the neighboring router every 30 or 90 seconds.. So therefore they transmit update... So how is that false.