The third category of writing protocols is advanced distance vector.
In theory you GOP or enhanced interior gateway writing protocol takes the best of both distance vector
and link states writing protocols and combines that into a single writing protocol.
You may see that the GOP is described as a hybrid writing protocol where it combines elements of both
distance vector and link state into a single writing protocol that isn't entirely true.
And in the GOP videos we'll discuss that in a lot more detail.
In theory the GOP takes the best of distance vector in that it's very easy to configure.
You could configure the GOP on a router as an example by using just two commands and thus it's very
easy to configure in the same way that REPP in the past was easier to configure.
GOP however forms a neighbor relationships in a similar way to link state routing protocols such as
OSPF.
So unlike distance vector writing protocols like REPP that do not form neighbor relationships GOP does
form neighbor relationships.
So in theory it's taking the best of both distance factor and link state and combining them into a single
routing protocol that gives you the power of a link state routing protocol with the ease of configuration
of a distance vector routing protocol.
The disadvantage of LIGO IP is that it's Cisco proprietary.
So unless you are running a pure Cisco network you may have to choose a different writing protocol such
as OSPF.
If however all your devices are Cisco devices job is a very good choice.
It's very easy to configure.
It's very quiet.
It updates very quickly and is a good choice for most enterprise networks that only have Cisco devices.
Another very important concept to understand is administrative distance which is essentially the believability
factor of a rocket when multiple routing protocols are configured on a router and are trying to put
Roths into what's called the routing information base or rub.
Also called the writing table a router will need to decide who to believe.
If OSPF says go left and Elijah up he says go right to get to a network which writing protocol.
Does the router believe.
And which route does it insert into the writing table.
In other words what is the trustworthiness or believability of the routing information back to the rotis
receiving administered of distance is then used as a tiebreaker to determine which way to go when multiple
writing protocols tell the rodded to go different ways.
As an analogy at minister of distance is used as a tiebreaker to determine which way to forward traffic.
If I was B-F says go left and your job he says go right the use uses a minister of distance to determine
which writing protocol it believes most technically what happens is that the writing protocol with the
lowest administrative distance is more believable.
And it's a routing information is inserted into the rub with writing information base or writing table
in preference of other writing protocols that have a higher administrative distance.
So the GOP has a lower administrative distance than OSPF UI GOP has an administered distance of 90 P.F.
has a minister distance of 110.
So internal E.I. GOP would be preferred over a week if so the lower the administer of distance the more
believable a writing protocol is.
You cannot believe anyone more than yourself.
So a Rodda will believe routes that it originates above rats received from neighboring devices a directly
connected interface has a believability factor would minister of distance of zero a static route configured
to a next hop IP address has a minister of distance of one when a static ragi is configured to directly
connected interface it is deemed to be directly connected and therefore has a believability factor or
admonition of distance of zero.
The reason why static routes have such a low administrative distance is that the router believes that
you know more than other routers do you as the administrator are supposed to know what you are doing
and thus the router believes you more than it believes Roths received via routing protocols such as
always P.F. or GOP.
Yeah GOP has an advantage of distance of 90 for internal rats.
Those are rats that originated in the GOP and were not redistributed or taken from a different routing
protocol and then put into the GOP OSPF has a distance of 110 reape has an immersive distance of 120
and unknown Rantz have an image of distance of 255.
As you can see the GOP has a lower administer of distance than repped does and that's because the GOP
is a better or more powerful routing protocol.
Yeah GOP will take bandwidth and delay into account when determining the best route Ripp only uses hop
count.
So yeah GOP seemed to be better than always P.F. which is better than rap.