• United States

How we did it

Apr 14, 20032 mins
Network SecurityWi-Fi

How we tested the various WLAN analyzers.

We performed several wireless LAN tests. We configured a WLAN infrastructure consisting of five 802.11b access points, two 802.11a access points, two 802.11a/b hybrid access points and two 802.11b+ access points over three logical Ethernet segments, connected together via an Ethernet switch. The 802.11b+ access points were not configured in 802.11b plus mode because all of the analyzers detected a speed error and could not otherwise access them. We used access points from Proxim/OrinocoD-Link (802.11b, 802.11a/b, 802.11b+), NetGear (802.11a/b), Linksys (802.11b, 802.11a, 802.11a/b), Intel (802.11b), and Buffalo Technologies (802.11b).

We checked that each analyzer could identify all access points, identify access points (both 802.11 a and b where possible) with identical media access control (MAC) addresses, identify, associate with, and use Dynamic Host Configuration Protocol on access points; get an address from the DHCP server on the network; and detect SMTP on an access point. No analyzer we tested could detect SMTP.

We also checked that each WLAN analyzer could detect Wired Equivalent Privacy (and its level and correct implementation); identify ad hoc (bridged access points) vs. infrastructure modes; and identify additional modes of WLAN security (802.1x).

Three test-configuration problems also needed to be identified: duplicate client MAC addresses, duplicate IP addresses and routing problems. We also placed an 802.11b access point nearly out of range (65 meters away and elevated eight meters) to see if an analyzer could detect its presence and the aforementioned analysis on it.

We also deployed an 802.11g access point to see how the analyzers would react – the analyzers without exception triggered the 802.11g access point into 802.11b working mode. Native 802.11g mode (forced mode) was represented as noise or invalid data rate on the specific channels.

All the handheld analyzers were tested on an HP iPAQ 3800 Series Pocket PC. The AirMagnet and Sniffer Wireless PDA option use the Pocket PC platform – Fluke’s WaveRunner uses embedded Linux. All handheld devices were limited to testing 802.11b at the time of our tests.

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