Think about OSPF and EIGRP for a moment.
Now, I know we're here to talk about BGP,
but let's pause and think about those IGPs for a moment.
How do they determine the best path?
How do they know what gets installed in the routing table?
Well, in EIGRP's case, they used the feasible distance
calculation, those k values.
And in OSPF's case, they basically
use an aggregated accumulation of bandwidth.
Wouldn't it be nice if BGP just used one single metric
to determine what the best path is?
It would be nice, but that's not the case. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
It would be nice, but that's not the case.
BGP uses a series of factors or metrics or other items
to determine what the best path it should select is.
I mean, think about it.
It's the protocol of the internet.
A service provider's router is going
to be learning a route from possibly dozens or even
hundreds of different routers.
It's going to see a bunch of different advertisements
and a bunch of different paths.
So how it determines the best path
is going to be kind of complicated.
This skill is going to be all about, what WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
This skill is going to be all about, what
are the actual steps that router will take
to determine what the best path for a certain prefix
is going to be?
Some of those determining factors are kind of involved,
so there's going to be a little bit of demo.
Others are very straightforward.
So get ready to see it in the whiteboard as well
as the virtual lab.
Let's get going.
It's going to be big and fun.