Efficiently troubleshoot wireless LANs

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Efficiently troubleshoot wireless LANs [Copy link]

WLAN based on IEEE 802.11 standard has gradually entered the mainstream network, making the troubleshooting and security of wireless network as important as wired network. 　

　　Analyzers that support multiple modes can scan all 802.11 bands, including all channels in 2.4GHz and 5GHz bands, and display them in graphical form. From these charts, you can check whether the configuration is reasonable, what is the SNR signal-to-noise ratio, how much bandwidth can be used, and other related issues. If a certain AP has a lot of traffic, it may be because many clients are using this AP to access the Internet; on the other hand, it may be that a special application or protocol is occupying a lot of bandwidth. Technicians can carry wireless analyzers to search for "those who send the most traffic" and quickly determine whether there are applications such as MP3 downloads and BT downloads, which need to be prohibited in wireless networks. 　

　　RF signal failure 　

　　Unlike wired networks, the performance of wireless networks will be affected by the location changes of APs and clients and changes in the environment. When a client roams to a place where the RF signal is very weak, it may cause a blind spot in the wireless network. These blind spots will affect some applications, such as VoIP applications based on wireless networks. 　

　　Troubleshooting steps 　

　　When users encounter wireless connection problems, they usually seek help from internal IT support staff. If the technician can successfully log into the wireless network from the client location using the tester, the problem may be in the configuration or permissions of the client device. If the tester cannot connect to the server, the problem may be in the physical layer of the wireless or wired network. In addition, insufficient bandwidth, request queue timeouts, conflict interference, etc. may also be the root cause of the problem. 　

　　The network administrator can measure the signal strength and AP performance by scanning the wireless network environment from the fault location using the wireless tester. In passive mode, the tester's wireless network card only receives signals and does not send data. If the RF quality meets the requirements, the administrator can log into the wireless network in client mode for testing, such as login test, PING and throughput test. 　

　　Support security testing 　

　　As mentioned earlier, the wireless network is dynamic. After deployment, sometimes due to human error, sometimes some unauthorized devices are brought in to increase the wireless network access coverage. Many times, because the wireless network provides access services in three-dimensional space, unauthorized APs may connect in. In addition, this result may also be caused by design errors. 　

　　Network Review 　

　　From a security perspective, according to forecasts, in 2006, 70% of malicious attacks will be caused by security holes caused by misconfiguration of APs or clients. Wireless testing tools can help enterprises regularly review the configuration of APs and clients to see if these configurations comply with corporate security policies. 　

　　Research institutions recommend that enterprises regularly check device configurations. If an enterprise chooses a WPA network, PEAP is an effective authorization method, and administrators need to confirm that all APs are configured as PEAP. It 　

　　is necessary to conduct periodic on-site surveys of wireless networks. Network administrators can use handheld tools to analyze RF signal quality and see if performance has degraded.

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