what is a VLAN?

VLAN(Virtual Local Area Network)

VLAN   on what is a VLAN and we’re going to 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 going to 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 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 with the hosts over a 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 will sail and one is our finance department, we’ll sail and two were our guest network for any guests coming 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 Mitch making sure that you understand that point, so interview lands with VLANs again they’re called virtual local area networks but what does that exactly mean it means they provide us 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 are going to go off a lot more here in a searchwhenever 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 provide logical segmentation of Networks okay so how can this apply to more of a real-world scenario?



We can understand more about 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 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  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 blog network is connected to the  top switch our blue Network hosts our connection 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.


I hope it has been a useful article.