Look at some of the issues that can arise to topple your wireless network, with a special focus on wireless interference.
- A well-configured wireless network is gonna be like a refrigerator. It's just gonna run, and you're gonna forget about it if you're lucky. But problems do pop up. So what I wanna do in this episode is come up with three very distinct examples of problems that you can run into in the wireless world. Now these are, I'm not gonna say they're super common, but to be honest with you, once a wireless network is set up properly, it's hard to find any kind of common problem. But I will say that you have probably run into all three of these types of problems.
So let's start off with the big one, interference. Now when you connect to a wireless network, you establish a certain speed that you and that wireless network are gonna run at. Now let's just say I'm running a 802.11g. Now you'd think when I connect to a wireless device, that I would be running at 54 megabits per second. Well, remember, that's a top speed. Because of interference and things like this, speeds can slow down a little bit. So one of the first things you need to be able to determine is what speed have I agreed with my wireless access point to run? So let's do this in Windows 8.
Now what I've done here is I fired up the Windows 8 Resource Monitor. And you can see that right now, I'm running it around one megabits per second. Now you'd think, well, Mike, that's not good, especially given the fact that this is an 802.11n network. Shouldn't it be running faster? Well, it's only gonna run as fast as it needs to run. Ooh, even slowed down a little bit more there. But that's okay, because I'm fairly idle right now. To get an idea of what the connected agreed speed is, you have to actually go into the status of your link. Now if you take a look right now, my speed is set at 65 megabits per second.
Which the chances of me actually needing that kind of throughput is really pretty small. Now when you look at this speed in particular, if this speed begins to dip down, you've got a problem. And that usually points towards interference. The biggest places you're gonna find interference more often than not are number one, when you have wireless access points that start stomping on your channel. And in that case, you're gonna have to go out and do a site survey and see what's out there. The other thing that can happen are other devices like baby monitors, and portable phones, things like that.
The best way you're gonna be able to tell you got a problem is because things are going to seem slower. And there's a lot of things that can happen on the internet to slow things down. But if you consider the fact that it could be wireless, what you need to be able to do is find, depending on your operating system, what the negotiation speed is between your device and the wireless access point. Now Network+ isn't gonna test you as to all the different ways to do this for every different operating system. But the important thing is, is you need to see what your established link speed is, and see if it's dropping down to something very, very low.
On mine, I might be running at 65 megabits per second right now, but if that were to drop down to 11 megabits per second, I know I've got an interference issue. If you've got an interference issue, there's only one of two things you can do. You could either kill the interference, or you can run away from it. When it comes to killing the interference, that means, ooh, gee, maybe this baby monitor isn't going to be good for our house, so we're gonna have to get rid of our baby. I mean, so we're gonna have to find a baby monitor that runs at a different band. They all run at lots of different bands. Or the other thing that you could do is to actually, for example, manually set the channel for your wireless access point to something that's a little bit further away from everybody else.
The other big issue that comes up all the time on networks is when you log in to a new network. It's a brand new network. It asks you for the passphrase, or whatever it is, and you type it in, and then all of a sudden, it says, you're connected. Yay, hey, I'm connected. But the problem is, is you can't get on the internet. Whenever you see that issue, the very first thing you need to do is check your IP address. If you have a 169.254 address, an APIPA address, you've probably typed in the wrong password.
If you think about it, your first glance would say, well, why doesn't it tell me I have a bad password? Because password hackers would love for that to happen. It can't tell you you have a bad password. It could simply not let you on. So the big clue for a bad password is that APIPA address. All right, the third issue that comes into play is usually something that takes place when you've been working on a particular network for a while, and suddenly, you can't get on. To appreciate that problem, let's take a look at Windows 8.
The big thing that people forget to appreciate is that there's two very different aspects to a network. One of them is the site survey. I always like Windows 8. They have a real pretty one that shows up like this. And then the second one is what we would call a connection itself. So if you take a look here, this is a connection. Now we call these profiles. What happens is, is that once you've made a connection to a particular SSID, everything's gonna be remembered. So for example, connect automatically when this network is in range.
So it's gonna automatically try to connect to this. And this is stored in your computer. And it's stored remembering a lot of things. Like for example, there's no authentication in this case. So if I were to suddenly go into my wireless access point and change it from no authentication to WPA2, which I probably oughta do, you're not gonna be able to get on. The network will still see the SSID, and you'll start clicking on it and all this stuff. But it's just not gonna connect, because your system itself, because it has established a profile, still thinks that it's an open network.
So to deal with that, we have to do this. Now every Window's client's a little bit different. But they've all got some option somewhere that says forget this network. So I go ahead, I go through the process of forgetting that network. Now you'll notice that it's still there for me. But I have deleted the profile is all I've done. So I can reconnect to it. Now this time, if there were a password on it, it would go ahead and automatically prompt for the password, and the profile would be re-established.
Now in this particular episode, I just gave you three examples. Most of the problems that you're gonna run into on the Network+ are pretty commonplace. It's going to be the things where you didn't type in the right SSID, or the WAP isn't actually connected to the internet itself, things like that. But do keep in mind on these three particular type problems, you may see 'em again.
This Total Seminars course covers the exam certification topics. For information on additional study resources—including practice tests, lab simulations, books, and discounted exam vouchers—visit totalsem.com/linkedin. LinkedIn Learning members receive special pricing.
This course was created by Total Seminars. We are pleased to offer this training in our library.
We are a CompTIA Partner. As such, we are able to offer CompTIA exam vouchers at a 10% discount. For more information on how to obtain this discount, please download these PDF instructions.
- Implementing wireless security
- Threats to your wireless network
- Wi-Fi Protected Setup
- Installing a wireless network
- Cloud ownership and implementation
- Creating a virtual machine
- PaaS, SaaS, and IaaS
- Mobile networking
- Deploying mobile devices