Question ID: #299
I took the TechExams online test and got this question "wrong".
Question 29 (Question ID: #299)
Which of the following are true concerning Split Horizon?
A. Is used only by link-state routing protocols.
B. Routing updates are sent immediately when new routes are learned rather than waiting on the update timer to expire.
C. Is used only by distance vector routing protocols. (Correct answer)
D. Routing updates received on an interface are not sent out the same interface. (answer I selected)
I feel like both answers are correct but the question only allowed you pick one. On the Cisco exams you are told to pick the "Most Correct" when only given one option but I feel like both of these are equally correct as one is not "more correct" or "less correct" given both points are facts.
Split Horizon is as defined on Wikipedia:
In computer networking, split-horizon route advertisement is a method of preventing routing loops in distance-vector routing protocols by prohibiting a router from advertising a route back onto the interface from which it was learned. Thus when a device that participates in such route advertisements receives an update from an interface, it (the device) does not forward updates through the same interface out. By doing so, routing loops are prevented.
(Split horizon route advertisement - Wikipedia, the free encyclopedia)
I know Wikipedia isn't the best source but I'm also basing this on everything I've ever been told about split horizon. I'm sorry if this was brought up in the past and I didn't see the notes somewhere but I'm hoping this:
B.)Someone points out the flaw in my logic.