Wireless Access Points

CompTIA Security+ Certification (SY0-501) Chapter 7 - Beyond the Basic LAN
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Transcript

A lot of people get surprised when the security plus covers the concept of wireless access points because wipes while they certainly do have some security issues, we tend to not zero in on just the wireless access points when we're talking about that. And unfortunately, that's a mistake. Because there's a lot of issues, particularly with your wireless signal that's getting out that are real security issues. So let's make sure we understand a couple of things before we get into deep. Now the most important thing I want to start off with is the idea of think enterprise. Now, what I've got here in front of me is a good old home wireless access point, but it's actually a lot more than a wireless access point.

If you take a look at this guy, you'll see he's actually a built in router. You see these in people's homes and in small offices all the time. They're great little boxes, but when we're talking about real security, we move into a whole other world. So what I have here are some wireless access points that are a little bit more serious when it comes to to dealing with enterprises. First one I want to talk about is this beastie. So this beasty is a wireless access point.

This is a made out of steel. This is a Cisco wireless access point. It's actually just been retired here, total seminars. Now, this is what we call a thick client. This is a standalone wireless access point. When you take a look at a beast like that, what you're talking about is a device that we have to configure by itself.

So if I've got three of these up there, I've got to go into each one. They all have web interfaces. I'm going to go into each one of these guys. I'm going to do whatever configuration I need to do. And that is a great example of a standalone or a fat client. Sometimes you hear the term thick client as well.

What's a little bit more common today in the enterprise environment is something like this. So what this is is a wireless access Access Point, you'll notice it's a lot smaller. This type of wireless access point is very different from that big thick client. This is what we're going to call a thin client. You don't go into this guy and configure him through a web page. This guy has to be handled through a controller.

So it's controller based. These are actually very, very convenient because what I can do, a lot of times if I'm setting up a wireless network for a office, I'm going to be using the same SSID I'm going to be bouncing around different channels so each wireless access point is got a good Chris signal. And I want to configure all these guys we call them hockey pucks you'll hear that term quite a bit. And I want to configure them all at once. So what we'll do like here at total seminars, there's a company called ubiquity. Love you ubiquity that has a wonderful powerful tool.

I buy a number of these hockey pucks I placed them properly, and then I plugged them in to a switch and threw one controller one piece of software, I set them all up simultaneously. When you've got a lot of wireless access points, the hassle of going through a whole bunch of thick clients versus just one little thin client controller is much, much better. Okay. So whether you have a fat client, a thick client or a thin client, a hockey puck, you have to deal with the issue of antennas. Now, if you'll notice, pretty much all of these devices have built in antennas ready to go. And for most of us, these antennas are absolutely fine.

This guy here doesn't look like it, but he's actually gotten intended to. However, if you need too many of these wireless access points, have the ability to take an external antenna like this little guy I've got right here and put that up there so you guys can look at it. The idea behind external antennas is that sometimes the built in antennas that come with a wireless access point, don't provide an signal. And signal strength is a big deal with these. When we're talking about signal strength, we use the term decibels, or DBI. So I don't want to get into a big decibels discussion because all your radio guys are going to jump out of your videos and beat me up because I'm not a radio guy.

The bottom line is, is when we're talking about DBI, what we're talking about is think about like a boost. how good of a signal does this device have, without that antenna or with a built in antenna versus me adding a stronger antenna? So in general, a larger decimal value is better and that's really important for the exam. Okay, so next thing I want to talk about are the different physical antenna types. There's a lot of I mean, they'll just look like little sticks, right? Well, there's actually a lot more to it than that.

It has to do with how the signal is presented. So let's go through the basic antenna types. First of all, we have what's called an omni or an omnidirectional an omnidirectional basically looks like a big basketball. So the signal goes in every possible direction. You'll see these used out of doors in very, very large like a basketball court or something like that. Because everybody no matter which directions pointing needs a signal.

Secondly, we have what's called a dipole. Now, this little, these little antennas here actually dipoles when we say a dipole actually has two little antennas built in so it looks like one antenna but there's really two. A dipole makes basically take a bagel and then stomp on it. And that's what a dipole signal is. dipoles have some real big benefits. Number one, they're really good if you're just trying to shoot To around a single floor, or if you're just trying to hit a single level or a deck in a ship or something like that.

The other nice thing about dipoles if you look right here, you'll see these dipoles always are bendy like this. And the reason they do that is because a lot of times, especially with something like this, by little adjustments, I could hit maybe have not only the floor I'm on but maybe a second floor as well. So that's why dipoles are extremely common. Next are what we call directionals. Now, a directional shoots out a really long beam. So think about like a lighthouse, and how a lighthouse shoots out a really long individual beam.

There are two different types of directionals that we'll see. First is going to be what we call a Yagi Yagi. These look like the antennas used to see on tops of people houses, and they're designed to pick up and send a very, very pointed signal. Now if you really want to Go crazy about it, then we can add what are called parabolics. So they look like little radar dishes. And these things are usually even more powerful than Yogi's in general, and they're designed for very, very long distances.

There's some really interesting competitions. Were using these types of antennas. They want to see who can shoot the furthest 802 11 distance now they're in the hundreds of miles and they have to shoot from mountain top to mountain top. Yeah, they're pretty nerdy. Okay, there is one more type of antenna that kind of directional and kind of Omni and that's called a patch. A patch is half of a nominee.

So what we're looking at is take that sphere and basically cut it in half. You can even have dipole type patches that will shoot basically half a dipole. The idea behind these is that these are great. In fact, this guy right here is a patch antenna. I can bolt him on to a wall in a office, and it'll shoot out a big signal in one direction, and virtually no signal at all at the other direction. So if I've got an exterior wall, and I don't want people in the parking lot trying to get into my wireless network patches are extremely common.

Okay? The idea behind antennas like this is that you have to place them. So the questions that you're going to see on the security plus are actually pretty trivial. So if you're doing something in a big basketball Stadium, you'd probably use a nominee. If you're outdoors, you're probably going to be using some form of dipole. If you're going to be placing things against walls look for a patch.

And if you ever have to shoot long distances, in particular, like between buildings and such, you're always going to be using some form of directional either a Yagi or a parabolic. Also keep in mind that with Yogi's anything that's directional, they actually have to be pointed to each other. So don't be surprised if somebody says Oh, point that to the left, or point that to the right. So you're always thinking in terms of direction. All right now, with a good understanding of antennas, we've got a good start in terms of our security. Good antenna placement controls the signal and make sure that we're not putting it in places where naughty people can.

And that's the most important thing to remember when we're talking about the different types of antennas. Now, I want to stop for a minute and talk about something that's completely different all still in wireless. Let's take a moment and talk about band selection. The 802 11 standard has two different bands, the 2.4 gigahertz band and the five gigahertz band. Now, when we're talking about the bands you're going to use it really boils down to the technology that you want, and the relative speeds that you want, and how crowded things are. So what I'm using is a Wi Fi analyzer built into my phone, right?

Right here. And I'd like to start by just taking a look on this phone. And look how crowded everything is. This is a mess of the 2.4 gigahertz band. Now, 2.4 gigahertz is fine for older 802 11 Technologies. But the real excitement is when I watch this as I switch over as we go into the five gigahertz band.

Now in this case, the five gigahertz band isn't nearly as crowded. And especially with technologies like 802 11 ac, you're pretty much going to want to go to the five gigahertz band, every now and then you'll see somebody supporting 2.4. And that's if somebody comes in with a really old laptop or something like that. So five gigahertz band is where it's at. The challenge with the five gigahertz band is how do you deal with your channel with now with 2.4 gigahertz you have very specific channels and on wireless access points, you can often set that channel very common today. With the more common standards in the five gigahertz band.

It's rare to run into wireless access points that allow you to manually configure the channel. And there's a good reason for that. A wireless access point today has auto sensing features. And if it senses that a particular channel is really, really crowded, it's just going to go ahead and go to someplace else. And we liked that feature. So automated channels on five gigahertz is common.

However, there's something else that is not common and that is channel width. Now, when you take a look at the different types of channels in the five gigahertz bands, you have 10 megahertz wide, 20 megahertz wide, 40 megahertz wide and, and in general, the wider the channel, the better the throughput you're going to get, especially when you're using more advanced technologies like MIMO with 802 11 ac. The downside is and let's take a look at the screen one more time is that if you take a look here you can see where it says total Wi Fi studio. Look how wide that channel is. We We've done that on purpose, because when I originally set this up, there wasn't anybody else in here. And I had this amazing throughput.

So and even as I'm watching this, I realize that I'm going to have to go into my wireless access points and narrow that channel with so that they can find an easier place to auto hop into that isn't quite so terribly crowded. So that's what we need to cover for the security plus on wireless access points. For me, number one, I'm always going to prefer a thin controller based client over a fat client, especially if I have two or more wireless access points. I'm going to take a lot of time not only selecting my antennas, but also making sure that the antenna placement supports just my users and nobody else. And third, I'm going to take the time with my band selection and my channel with to make sure that I've got the best possible signal I can get

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