What is a VLAN? Virtual Local Area Networks

welcome everyone my name is Jacob Hess and I'm here to take you from zero to engineer welcome to today's quick nugget on what is a VLAN and we're gonna go ahead jump right in here and answer that question real fast and just say a VLAN is a virtual local area network well no we're not gonna just stop there but I wanted to preface with that it's called a virtual local area network now we'll define that a lot more here in a minute but before we do I'd like to make sure you understand how traffic flows for regular lands without VLANs now the aliens have been around for a long time since the 90s so they've been used for a long time we use them all the time they're a huge important topic and networking but before we can understand VLANs we need to understand pre VLANs so before we add VLANs we would create separate networks like this laying one and LAN two and the point here is we have to physically separate switches so the host connected to land one cannot communicate to the hosts over at LAN 2 now I think we can all agree on that right because there's no connection between these two switches they're physically separated their own physical different networks so before VLANs this is the way things work now why would we want to have hosts in different networks we'll take for example if we have a finance department for you well sail and one is our finance department we'll sail and two was our guest network for any guests coming in so it's obvious that we would never want our guests network traffic or hosts on the guest network to be able to reach the host in our finance department right that wouldn't be good for a company so in that case we need to separate those networks and before VLANs we had to do that physically the hosts needed to be physically connected to separate networking Hardware in this case switches write separate networking switches so that's a great point in order to separate the traffic from LAN one tool and two we would have to have them connected to separate switches ok Mitch making sure that you understand that point so intervie lands with VLANs again they're called virtual local area networks but what does that exactly mean it means they provide us with lot call separation or segmentation of our networks so we can take a single switch for example and chop it up into multiple logical networks where there's different where the traffic is actually separate in each one of those networks all right so let's define that a bit more further we can have multiple networks or VLANs all on the same networking hardware or networking switch so taking our example here where we have two completely separate networks well if we were to use VLANs we could actually have them all on the same hardware but still be separated so we could have our single switch here and implement VLANs and then we could have our two separate lands or two separate networks attached the same physical device the same networking hardware but we can still keep their traffic completely separate and implement our own security controls on those networks individually and separately so you can see the importance of VLANs here now you're good the light bulbs gonna go off a lot more here in a sec whenever we describe more of a real-world scenario but this is the basics of it this is the gist of it so the traffic is still completely separated from VLAN wine and VLAN two but it's done logically inside the switch rather than physically all right so that should make some sense for you now the last point I wanted to make for we move on to the next topic is that our VLANs provide us with logical segmentation of networks that's kind of my final definition for you on VLANs VLANs provide logical segmentation of networks okay so how can this apply to more of a real-world scenario we can understand more of this concept and understand how VLANs give us freedom and allow us to be unlimited in our physical locations of hosts well let's look at a situation where we have a building for example so let's say that you're a network engineer and you manage the the networks of this building and you went in installed switches on every floor well let's think preview an era we would have to well if we wanted to have four different networks we would have to have the hosts for each individual network all connected to the same switch for example it would look something like this we four different networks we got the black blue green and yellow networks here just for simplicity purposes using colors but you can see here we have our our black network is connected to the top switch our blue Network hosts our connect to the second switch so forth and so on the point is for the host to be in the same network they got to be connected to the same piece of hardware that's before VLANs now inter VLANs and it doesn't matter where the hosts are we can put them in any VLAN we want to no matter of their location now in a normal Network all these switches here all the switches you see in the building would all be interconnected they would all share the same VLAN database they would all know about all the villains in the network and you'll be able to just go into any switch and assign any host to any VLAN so that gives you vast amount of flexibility and this guy's is the purpose of VLANs we logically separate our networks using VLANs and that's the point now alright guys so that is the lesson on today's quick nugget on what is a VLAN my name is Jacob Hess your instructor and mentor and as always thank you very much for viewing and I'll see you in the next video thank you guys for viewing the video I hope you really enjoyed it and I'd also like to remind you that if you're truly serious about your career in information technology be sure to check out our career blueprint and engineer training program and ww0 to engineer calm you

Channel: NexGenT

Views: 559,812

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Id: oo-hejIq3iQ

Length: 6min 21sec (381 seconds)

Published: Fri Dec 01 2017