[AUDIO LOGO]
Congratulations on completing another skill.
Now it's time for a review in the form of a quiz.
As we go through these questions,
be sure to pause the video after each question to give yourself
the opportunity to answer the question yourself
before we then go over the answer.
That said, let's jump in with our first question.
What is the purpose of VRF-Lite?
Now, this being a fill in the blanks type question,
as long as we have something along these lines,
it's going to be correct.
The idea here is that we can run OSPF in a VRF
on a device that's not acting as a PE router, therefore,
it's not supposed to be implementing PE loop
prevention.
The main purpose for this, of course,
is to allow a customer to use a VRF for their OSPF routing
for whatever reason they may want to.
Next question, what is the default OSPF cost
of a SHAM link?
Now, this could be a little bit of a trick question
just because we didn't point this out specifically.
However, when we looked at our routes
after implementing the SHAM link,
those routes had a cost of 4 or less.
So that pretty much indicates that the cost of that SHAM link
has to be 1.
And if you think for just a moment,
it really does make sense.
The whole purpose of building the SHAM link
is because you want to use the path through MPLS.
So if you want to use the path, you're
going to want to give it a very low cost i.e.
1.
You would not want to give it a ridiculously high cost.
We're trying to use this path.
So the correct answer for this is
number 4, which is a cost of 1.
Final question, what is the difference between an OSPF SHAM
link and an OSPF virtual-link.
Now, we didn't directly discuss OSPF virtual links
in this skill.
However, you should already be familiar
with OSPF virtual links.
But at bare minimum, we should be
able to describe a SHAM link here.
So the virtual link is used to extend only area
0 through another area.
The SHAM link, however, is used to extend any area but not
through another OSPF area through our MPLS environment.
And of course, the purpose of this
is to allow those routes to come through as intra area
so that we can actually choose to prefer them
over maybe something like a back door or a backup link.
So that concludes this quiz.
If you find that you are missing any of the information needed
to answer these questions, I would
encourage you to go back and review the referenced sources
on each question.
Otherwise, congratulations on completing
Implementing OSPF as the CE-PE.
I hope this has been informative for you,
and I'd like to thank you for viewing.