[MUSIC PLAYING]
Welcome to OSPF Path Selection.
In this skill, we're going to be jumping in
with some more detail into the OSPF path selection process.
Now if you ask most engineers out there,
how does OSPF choose the best path to a destination?
You'll probably get the rather common answer
that it's the lowest cost, or the lowest path cost.
And that is probably the most common place
that the decision in OSPF happens.
However, there are rules that come before lowest cost.
And in the event of a tie with lowest cost,
there's a few rules that come after it
as well as tiebreakers.
Now keep in mind, if we do get to the very bottom of our list
and there are still two or more equal paths,
we will do equal cost multi-pathing or ECMP.
So keep that in mind as we go through this process,
that there is a little bit more to this than just the lowest
cost.
That's of course, our main focus of this skill.
But also keep in mind that even if we
get through this entire process, and there is still a tie,
it doesn't mean that we can't use multiple paths.
This is not BGP which will go all the way
to choosing one best path.
With OSPF, we can do equal cost multi-pathing.
So let's jump in and get started.
We have a whole list of things to go over.
We're going to look at that list.
And then we're going to jump into each one in detail
and prove exactly how it works.
So a lot of cool stuff.
Let's jump in and get started.
I'll see you in the next video.