Question about Link-State Routing Protocols

rob909e

After taking a practice text, I noticed a question was marked wrong that I feel should've been right. The question was something like..... True or False. Link-State routing protocols do NOT send out periodic updates. I answered False and it was marked wrong. However, OSPF, a link-state routing protocol, sends a update every 30 minutes by flooding the routers links. This is an update. This is a link-state protocol. Knowing the above information, how is the answer to the question True? Also, Will the CCNA through out these kinds of BS questions? Thanks Rob

CE1028

Hello,

Link State Protocols do not send periodic updates. When each LSA age expires, the advertising router will change the sequence number and re-flood only that LSA.

So the correct answer is true

rob909e

Really.... Then how come almost every book, website and other sources of OSPF information say otherwise.... Ex. https://ccnproute.wordpress.com/tag/ospf-updates/ Link-State Routing Protocols They respond quickly to network changes. They send triggered updates when a network change occurs. They send periodic updates, known as link-state refresh, at long time intervals, such as every 30 minutes. .... Doesn't get ANY clearer than that...

Pseudonym

That website is a link to someone's study notes.

rob909e

Thanks for proving how UNRELIABLE some internet sources are. The internet has a wealth of knowledge on networking and the CCNA. I've been using 3 different books for my readings and I've found when I don't understand something, Google. Although very helpful, google can yield false information, Fake news so to speak. CCENT, CCNA, CCNP, CCIE..... Some of these book I've been reading will dumb down ideas and concepts for the purpose of learning the basic foundation. I've found throughout my CCNA studying, when some ideas are dumb down, they can be accidentally misinterpreted, inadvertently infecting the learning process, which, by the way, is a long and arduous endeavor. Thanks for your help!

CE1028

My guess is the question was trying to test your knowledge on the difference between link-state protocols and distance vector. When I think of periodic updates, I think of RIP which sends the update periodically, regardless if there are changes or not.

Best of luck with your studies