It really can't be denied that Ethernet switches, transparent Ethernet switches were just revolutionary
in the local area network environment for sure.
Remember, hub based networks before we had network switches were a nightmare because there would be
no creation of these small collision domains.
You'd have all of these collisions occurring.
So there was limited bandwidth and just nowhere near the scalability that we have when we do networks
built with network switches.
Let's review some of the basics here.
With network switches, we have really what's called transparent, bridging taking place.
And what this means is the switches are transparently meaning.
The frames that are moving through them don't detect anything is being done.
And these network switches are eavesdropping on the MAC addresses that are being used in the frames.
The switch is quickly able to build a map, if you will, of the ports to the MAC addresses.
These mappings are then used to intelligently forward out the port that is needed to communicate to
a certain Mac address and to filter it out all of the other ports.
So that's how network switches work.
Their magic.
The ability of the switch to create additional virtual local area networks is a great capability as
well because we know the more devices that are in the same broadcast domain, the messier that's going
to be.
If, let's say we have four devices that are connected to this network switch and we can think of those
four arrows as representing those four devices.
If they're all in the same broadcast domain, when one of the devices sends a broadcast, they'll all
all three of the other machines will have to receive it.
But if we carve out VLANs in the environment, let's say putting the two arrows facing left in one VLAN
and the two arrows facing right in another VLAN.
Well, now we have two broadcast domains and when there is a broadcast sent it won't go to all three
other machines.
So VLANs are a great thing for the creation of additional broadcast domains.
Now, remember, when it comes to network switches today, some are going to be much more sophisticated
devices than just transparent switches.
They will be routers.
There will be firewalls.
So we can get network switches that are huge in actual physical form factor.
And they could be filled with modules that do all kinds of things.
High speed routing, sure, switching of traffic, but maybe also again, security mechanisms like intrusion
prevention systems.
So don't count out the switch as a powerhouse in your network because oftentimes it is.
Thanks so much for watching this video on our network switches today.