Troubleshooting Wireless Configurations – CompTIA Network+ N10-006 – 4.3

| May 8, 2015


The configuration of your wireless access point can have a dramatic impact on throughput and performance. In this video, you’ll learn about SSID configurations, encryption settings, power levels, LWAPP, environmental factors, and issues with wireless standards.
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There are many different configuration settings and variables when you start installing a wireless network. And in this video, we’ll look at how you can troubleshoot some of these configuration options. When you have multiple access points, you want people to be able to automatically roam from one access point to the other. But to do that, you need to make sure that all of your access points have exactly the same SSID. If there’s a difference between those SSIDs, you won’t be able to seamlessly move from one to the other.

You might also want to configure your wireless devices to avoid connecting to open wireless access points and to only connect to wireless access points that they trust. When you work with many different wireless network standards and there are different wireless devices, you might run into some incompatibilities. Not everything follows the standard to the letter, and you may find that setting a wireless access point to hybrid mode may cause some devices to connect to the wireless network and others may not.

This is a challenge to troubleshoot, of course, but you may want to set different wireless settings for the standards and see what differences they might make with different chipsets in your environment. Every wireless network needs to have encryption enabled, so you should be running ideally WPA2 or WPA2 Enterprise. All of the encryption keys need to be the same across all of your access points, or the authentication method needs to be the same if you’re running WPA2 Enterprise.

That way a user can be on one access point on one side of the campus, they can walk to one side to the other and easily roam between all of the different access points because the encryption settings are exactly the same on every single one of them. The network administrator also has to be aware of the possibility of rogue access points, whether this is one that a user has brought in themselves or a third party is using their own access point to try to gain access to the information in your network. When you’re working with many access points, you have the option to define what the power level is going to be.

So you should set it as low as possible so that the people within your building or area can use that wireless access point, but you’re avoiding sending that signal outside of your building or into areas where you don’t want someone to gain access to the network. You also need to engineer your wireless network with the right antennas. If this is something in a general area, you might use a unidirectional antenna. But if you’re trying to communicate across to another building, you may need a more directional antenna to be able to make that leap across such a long distance.

You should also be aware of MIMO configurations within your wireless access point. You may have the option to enable or disable different receivers and transmitters and use different antennas that are on the back of your wireless access point. This will help refine the signal when it’s received and certainly helps when you’re sending large amounts of bandwidth out to the wireless network. If you have a large number of access points and you’d like to manage them from one central place, you can use a very standard protocol called LWAPP or LWAPP. This is the Lightweight Access Point Protocol.

It’s a proprietary protocol from Cisco. There is an open protocol called CAPWAP, it’s an RFC standard and it is an alternative to using the proprietary Cisco LWAPP. This allows you to manage these multiple access points all from one single place. So if you need to make one configuration change, you can make it on one screen and push that change out to all of your different access points simultaneously. If you’re managing access points, then you’re probably using either thick access points or thin access points.

A thick access point is one where the wireless access point is handling a lot of the tasks itself. All of the configuration settings, all of the work that is done with switching, everything relating to the access point is all happening on that device. The access point is often connecting to a switch, but the switch just sees this as just another device. The switch has no knowledge of any wireless functionality that’s associated with that access point.

That’s very different with a thin access point where it has just a minimum functionality that provides the wireless capabilities, and a lot of the function of the wireless control and management is handled on the switch. All of this intelligence is pushed down to the switch so we can have less expensive access points and ideally deploy more of them over a larger area. We obviously can’t see the wireless signal as it’s being sent out from the access point, but we do need to be concerned about where these wireless signals are going.

The environment where the signal is has a very big impact on the performance of the wireless network. We should look to see what concrete walls might be in the way because different frequencies react differently to concrete. 2.4 GHz signals tend to pass through walls better than the 5 GHz signal might and the 5 GHz might reflect off of those walls. This might be a good thing or a bad thing depending on if you’re trying to keep the signal in a very small area, but it certainly has an impact on the overall engineering of the wireless network.

In some environments, we have to be aware of the type of film that is on a window. Some window film can decrease or attenuate the wireless signal passing through it. This might be, again, very good if you want to keep that wireless signal on the inside of a building, but if you need to have that signal go outside, you want to be sure there’s no film on the window that will prevent that from occurring. Another important environmental concern might be inside of your walls. There might be metal studs and, of course, our wireless signals bounce and reflect off of those metal studs.

And of course, that will reduce the range that our wireless signals are able to go. Many of the throughput values that you might see associated with a wireless network are theoretical maximums, but in your environment, you might have a lot of different variables that might cause the throughput to be lower than what’s listed as a theoretical maximum. You should also think about what frequencies are in use in your environment and which ones would be best for your environment. Although we think of 5 GHz as being the best frequencies to use, in your particular environment, you might want to have 2.4 GHz because it might go through walls better.

Or you might be using both 2.4 GHz and 5 GHz depending on what devices you have and where they might be located. Sometimes our wireless networks are not in the same room or the same floor of a building. Sometimes they have to extend over very large distances. And in those cases, we want to be sure we have a high gain antenna and that we’re using as much power as possible. And of course, if we’d like to avoid any interference on our wireless networks, we need to make sure that we have these frequencies set properly on our access points.

In different parts of the world, you have different options to different frequency ranges. So you need to make sure that you’re able to access all of the appropriate frequencies for your country. And if you can have the frequency set up to be non-overlapping, then you’re going to be assured that there’s no interference with any of your wireless networks.

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Category: CompTIA Network+ N10-006

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