Instructor

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Sybex CCNA 640-802 Chapter 12 Wireless Networks

• Instructor Todd Lammle

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Chapter 12 Objectives

• The CCNA Topics Covered in this chapter include
• What is a WLAN?
• IEEE Standards
• CSMA/CD
• ISM 2.4Ghz channels
• UNII Band
• BSS/ESS
• Wireless Security

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Wireless LANs

• Transmitting a signal using the typical 802.11
  specifications works a lot like it does with a
  basic Ethernet hub Theyre both two-way forms of
  communication, and they both use the same
  frequency to both transmit and receive, often
  referred to as half-duplex.
• Wireless LANs (WLANs) use radio frequencies (RFs)
  that are radiated into the air from an antenna
  that creates radio waves.

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Unlicensed Frequencies
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802.11 Standards

• Here are the most popular standards in use today
• 802.11b 2.4Ghz, maximum bandwidth of 11Mbps
• 802.1g 2.4Ghz, up to 54Mbps
• 802.11a 5Ghz, up to 54Mbps

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802.11b CSMA/CD
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ISM 2.4 Ghz Channels
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UNII 5Ghz Band
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Range Comparisons
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BSS/ESS
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Wireless Security

• All Wi-Fi Certified wireless LAN products are
  shipped in "open-access" mode, with their
  security features turned off.
• SSID, WEP and MAC authentication
• 802.11i
• WPA and WPA 2

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Summary

• Summary
• Open your books and go through all the written
  labs and the review questions.
• Review the answers in class.

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