Errol explains the top five benefits of implementing Virtual Local Area Networks (VLANs), including considerations such as performance, security, cost, location and management.
Hi, my name's Errol. Thanks for joining us. Today I'm going to talk about VLANs and the top five benefits of implementing them. A VLAN basically stands for Virtual Local Area Network. In its simplest form what that is is basically talking a layer two network that might be sizable and splitting it up into multiple networks. What that does is improve performance, improve security, lower your cost, gets over some of the location barriers that you have, and simplifies management.
Switches are pretty complicated but when you first plug them in and they're set to factory defaults basically anything can get to anything. This is all in one VLAN. Usually it's the default VLAN. As you add more switches that holds true. This is three switches right here. Anything plugged into this one can get to this. All this can communicate with each other. It's one big broadcast domain. As your network grows from one switch to three switches to a hundred switches that creates a problem right off the bat, and the problem is performance.
Being that this is all one broadcast domain, as you add devices to your network and they try to locate each other, traffic becomes more intense, it slows down your network. That's the first thing that a VLAN does is improve performance. How it does that is splits it up into multiple broadcast domains, so that actually anything in this red VLAN right here can't talk to anything in a green VLAN. It makes it smaller and more manageable as far as traffic goes.
When you first plug in a switch everything's in the same broadcast domain. It's pretty much a flat network. That's when everything's in the same VLAN. The second problem with that is what if you're in a company where you have maybe sales is this red switch right here and accounting is this other switch, and you don't want to them to talk to each other. Or maybe you're in education and you have students and faculty and administration. You don't want the students sneaking in to see their grades or answers to the tests.
How you would separate in a flat network is you wouldn't. Everybody can get to everybody. One way to separate that is to put a layer three device like a router in between. That way anybody on this switch can't get to anybody on this switch. The problem with that is that there's a cost to that; it's more expensive. VLANs pretty much keep it inexpensive by having the same switch. Maybe the red one is our students and the green is faculty and administrators, and they can't talk to each other. Students can't get their grades. Sales reps can't see their reviews or what other people are making by plugging into HR.
I already touched on cost a little bit, which is number three. I'm going to touch on it a little more. A third scenario is what if you have students in this location and faculty in this location, students in this location and faculty in this location. Without VLANs basically what you have to do is have a switch for each branch that you want. If you want students in this location you'll have to have a switch just for students, administrative switch just for administrators. Same thing with HR and sales. Sales are usually all over the place. This is one building and this is one building. You need a switch for each one. That gets expensive. You've got to buy the layer three device router. You've got to by a switch for each type of department.
When you have VLANs you don't need to do that. Basically there are two types of ports. There's an access port and a trunk port. VLANs can span over multiple switches. What you do is you create a VLAN here in this building, the red VLAN which would be students, the green VLAN which would be administrators. They can't talk to each other. These are access ports which means they only belong to one VLAN. Trunk ports can carry the information from multiple VLANs to another switch, so that way when you go over to the other building you have the same VLANs here. These green people right here, which are faculty, can get to these and it basically logically looks like this but it's really configured like this. Same thing with the students. They can't touch this or this but they can talk to the red. That's how you would get over location barriers and keep the cost down for that.
Number five is management. It simplifies management because let's say if you have a new student come in, a new employee, and you know that this employee is going to be in sales or this student is going to be at a certain part of the dorm or anything like that. Then what you can do is you already have the VLAN set up, you create a port, put them in a student VLAN, put it in a sales VLAN, plug it in, and all his credentials are set and he can go only where you want him to go. You don't have to configure each one individually. You just configure the port for what you want him in as far as VLANs go and then he's all set, and that simplifies management.
Once again, I want to thank you for tuning in. I hope this video on VLANs and the benefits of it helps you with your understanding of it. If you have any more questions, feel free to contact us.