Wireless Networking Wireless Problem Discovery and Solutions Module-12 Jerry Bernardini Community College of Rhode Island 6/28/20151Wireless Networking J. Bernardini

Presentation Reference Material CWNA Certified Wireless Network Administration Official Study Guide, Fourth Edition, Tom Carpenter, Joel Barrett – Chapter-11, page /28/2015Wireless Networking J. Bernardini2

WLAN Analysis Systems Handheld Protocol Analyzers Laptop Protocol Analyzers Basic Protocol Analyzers Handheld RF Spectrum Analyzers Laptop RF Spectrum Analyzers Wireless Intrusion Detection Systems Wireless Intrusion Prevention Systems Distributed RF Spectrum Analyzers 6/28/2015Wireless Networking J. Bernardini3

Handheld Protocol Analyzers PDA-Based – Convenient – Low processing power and small screen – Medium cost ($1000) – PocketPC based applications – WiFi PPC, CommView, MiniStumbler, TamoSoft Integrated – Specialized – Powerful – Full featured – High cost ($10,000 to $25,000) – Fluke OptiView Integrated Network Analyzer 6/28/2015Wireless Networking J. Bernardini4

Laptop Protocol Analyzers Large choice of applications – Wireshark (PC and Linux) – Wildpackets Omnipeek – AirMagnet – Others Wireless adapter Driver Issues – Applications only work with certain adapters – Obtain application first – Download the needed drivers Adapter Choices – PCMCIA – ExpressCard – USB 6/28/2015 Wireless Networking J. Bernardini5

6/28/2015Wireless Networking J. Bernardini66/28/20156Wireless Networking J. Bernardini Cheep Way to View RF and Stations in Area

WiFi Hopper 6/28/2015Wireless Networking J. Bernardini7 Website:

6/28/2015Wireless Networking J. Bernardini8 Spectrum Analyzers Scan radio frequency spectrum and provides graphical display of results – Typically measure signal-to-noise ratio – Single-frequency analyzers measure signal-to-noise ratio at specified frequency – Helpful in identifying interference problems Thus, helps properly position/orient AP Costly $500 $50,000

Handheld RF Spectrum Analyzers 6/28/2015Wireless Networking J. Bernardini9

Handheld RF Spectrum Analyzers –Expensive 6/28/2015Wireless Networking J. Bernardini10 Frequency range: 100kHz - 6 GHz. Internal preamplifier with frequency range from 100 kHz - 6 GHz. Displayed average noise level typ dBm (RBW 100 Hz). 0.5 dB typ. level accuracy up to 6 GHz. Resolution bandwidths 100 Hz - 1 MHz, 1 and 3 steps. Wide range of detectors; sample, max/min peak, auto peak, RMS. Cost: $13,500

NSF Grant Other Spectrum Analyzers Frequency, f (GHz) Two basic types: Hardware and Software

Laptop RF Spectrum Analyzers 6/28/2015Wireless Networking J. Bernardini12 Fluke Cisco Other Cognio (now owned by Cisco)

Wireless Intrusion Detection Systems Cisco 6/28/2015Wireless Networking J. Bernardini13

Intrusion Detection System 6/28/2015Wireless Networking J. Bernardini14

Wireless Security Articles ntrusion_detection/ ntrusion_detection/ 6/28/2015Wireless Networking J. Bernardini15

Distributed RF Spectrum Analyzers 6/28/2015Wireless Networking J. Bernardini16

Case Study 1 FIGURE Filter configuration in CommView for Wi-Fi 6/28/2015Wireless Networking J. Bernardini17

Case Study 2 FIGURE Filtered capture in CommView for Wi-Fi 6/28/2015Wireless Networking J. Bernardini18

Case Study 2 FIGURE Two file transfers at different data rates 6/28/2015Wireless Networking J. Bernardini19

Case Study 2 FIGURE Captured frames from the shipping department’s access point 6/28/2015Wireless Networking J. Bernardini20

Case Study 2 FIGURE Captured wired frames between the engineering access point and the RADIUS server 6/28/2015Wireless Networking J. Bernardini21

Case Study 3 FIGURE Protocol analyzer showing the low RF medium usage 6/28/2015Wireless Networking J. Bernardini22

Case Study 3 FIGURE Abnormally high retransmission count 6/28/2015Wireless Networking J. Bernardini23

Case Study 3 FIGURE Spectrum analyzer showing narrowband RF interference 6/28/2015Wireless Networking J. Bernardini24