BCMSN 642-811 QoS Question

Well, technically speaking, you do need to apply the policy somewhere before it will work. So, the service-policy is needed for any traffic at all to be selected. This could go either way, depending on who is writing/grading the question. I really hate these vague, borderline questions. They don't really test your knowledge, just your ability to figure out the right 'Cisco' answer.

Since it says to select the '2 best answers', you need to choose C and the one that fits best for second place - that would be A.

Hope that helps,

Jim

Personally, I would think the Cisco Press book should be sufficient. They are written really with testing in mind, not really for true learning sake. All key points that are on the test 'should' be covered in the book.

Hey Jim,

thanks for your answer. Wouldnt the 2 best answers be class-map and policy-map since the class-map will be referenced from a policy-map and the policy-map will be bound to the interface using service-policy? So service-policy is only at number 3 ;-) Please share your opinion.

Thanks Sascha

Certainly a valid argument. Yes, policy-map could be considered a good answer. The best? Hmmm, subjective - and that is the problem. Class-map without a doubt is the best answer. For second best, I'll admit that I started with the answers they gave an thought why they would have chosen the answers they did. mls trust even applies a little bit, but would the weakest answer. I think the key word is 'identified'. Class-map does the identifying, policy-map does the marking based on the identities established in the class-map. Those are two different functions, even though one relies on the other. The service-policy says to only identify/mark traffic on the interface where the service-policy is applied. So, I say that this is the closest match. Who knows? Does the author give an email address? Perhaps you could send a query.

Again, I think the real problem is that the questions are vague without a clear answer - even to people who may know the material very well. A crappy subjective question at best.

I think the best thing for you to do is to make sure that you understand the commands, what they do, why and when they are used, and not get too hung up on the semantics of a few trick questions. You are bound to miss some, just cause there are dumb questions out there (case in point above). But, if you really understand what you are doing, you should pass.

JMHO,

Jim