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In this video, we're going to look at a lot of different
kinds of network topologies.
This is really useful to use when you're planning a local
network, a wide area network, and you're trying to determine
how best to connect these different sites together.
This can also be used for troubleshooting purposes.
If you know which way the data is flowing, it's going to help
you if you ever run into any problems,
A mesh topology is one where we have multiple links they
are going to exactly the same place.
You sometimes hear this referred to as a
fully-connected network.
This provides you with some advantages from a connectivity
perspective.
You've got redundancy and fault tolerance built in.
If you lose a connection, you've got multiple links.
You can simply use the other connections to
get around the problem.
And you also have the ability to do load balancing over some
of these connections.
With multiple links, now you have twice as much bandwidth
available to send your data back and forth.
It's very common to see a meshed network
on a wide area network.
We see fully meshed and partially meshed networks this
way, so that you can connect some sites via multiple
connections, some sites to be a single connection.
And blend together differences on how you want to be able to
connect between point A and point B.
We still see ring technologies used in many places.
You usually don't see it in the local
area network any longer.
Token ring is when you don't often see any longer.
But if you ever go into the back infrastructure in some of
these legacy devices, you may still see token ring equipment
powered on and sending data between a couple of devices
that have to be there to keep the business running.
Where you commonly see a ring network then
is in larger networks.
Things like your metropolitan area network and your wide
area networks will use rings because you have fault
tolerance there.
If someone is working on the road and they accidentally
break one of those connections, you've still got
connectivity that you can use to circle around the other
direction, because everyone is connected in a single ring.
A bus topology was extremely common to see an early
ethernet networks.
It's one we really don't see much any longer.
But it allowed us to take a single coaxial cable and
extend it from one end of the building to the other and
simply connect everybody into that one piece of coax.
The problem obviously with that is if you have a break
anywhere along this connection, then it's broken
for everyone who's on the network.
And you have a connectivity problem at that point.
We don't see bus networks around much longer.
But if you look into the wall connectors, sometimes you'll
see the remnants of an old coax network still sitting in
there from the days when we used to use those bus-based
ethernet networks.
The vast majority of local area networks use a star
topology to be able to communicate.
Everyone on the network is out and connected to a single
concentrator or switch that might be in the middle.
Everyone's connected into the same device or a series of
devices, for redundancy.
But you can see it's a star, because everybody is connected
into that central device.
Nobody's really connected directly to one another.
This is very common to see in switched ethernet, where
everybody's connected to a very, very large switch in the
middle of the building or on the floor of the building and
you simply have that one device sitting in the middle
of everything.
A hybrid topology is one where we've taken multiple types of
topologies and we've simply combined them together.
It's very common to see this in most environments.
You're almost always going to use multiple topology types to
connect your networks.
In fact you might have an ethernet network that's in
your core that is a star network but to connect out to
your remote sites, you've created a
mesh wide area network.
Using this combination of topologies allows you a lot of
flexibility.
And if you're planning a network, this will be a very,
very common way to lay out the structure of your network.