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[MUSIC PLAYING]

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Welcome to OSPF Path Selection.

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In this skill, we're
going to be jumping in

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with some more detail into the
OSPF path selection process.

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Now if you ask most
engineers out there,

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how does OSPF choose the
best path to a destination?

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You'll probably get the
rather common answer

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that it's the lowest cost,
or the lowest path cost.

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And that is probably
the most common place

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that the decision
in OSPF happens.

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However, there are rules
that come before lowest cost.

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And in the event of a
tie with lowest cost,

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there's a few rules
that come after it

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as well as tiebreakers.

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Now keep in mind, if we do get
to the very bottom of our list

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and there are still two
or more equal paths,

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we will do equal cost
multi-pathing or ECMP.

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So keep that in mind as we
go through this process,

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that there is a little bit more
to this than just the lowest

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cost.

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That's of course, our
main focus of this skill.

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But also keep in
mind that even if we

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get through this entire process,
and there is still a tie,

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it doesn't mean that we
can't use multiple paths.

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This is not BGP which
will go all the way

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to choosing one best path.

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With OSPF, we can do
equal cost multi-pathing.

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So let's jump in
and get started.

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We have a whole list
of things to go over.

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We're going to
look at that list.

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And then we're going to
jump into each one in detail

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and prove exactly how it works.

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So a lot of cool stuff.

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Let's jump in and get started.

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I'll see you in the next video.

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