Network+ : WiFi

  1. Network+ Certification
  2. Network+ Certification – Introductions and Resources
  3. Network+ : From Physical Topologies to Media and Network Devices
  4. Network+ : Networking Variants, Physical Installation
  5. Network+ : TCP/IP and Network Operations
  6. Network+ : Network Naming and Sharing Resources
  7. Network+ : IPv6
  8. Network+ : Remote, Secure and Cross-Platform Networking
  9. Network+ : Servers and Support
  10. Network+ : WiFi
  11. Routing and Firewalls
  12. Network+: Routing Protocols
  13. Network+: Network Monitoring

WiFi Standards

The world of WiFi changes fast, fast, fast. We’ve gotten used to calling different types of WiFi things like 802.11g and 802.11ac, but this system has gotten non-techies so confused the the WiFi Consortium has standardized on a simpler terminology: 802.11ax, for instance, is officially WiFi 6.

CompTIA says there are two modes of Wifi:

      • Infrastructure Mode
      • Ad Hoc Mode

There’s actually a difference between peer-to-peer and ad hoc, but not as far as this test goes.

Ad Hoc mode is disabled by default in Windows 8+, but can be enabled at the command line.

Standard Wifi Version Frequency Encryption Speed Beams Multiplexing
(“legacy mode”)
none 2.4 GHz 1-2 Mbps 1 keyboards, mice
802.11a WiFi 1 5 GHz 54 Mbps 1
802.11b WiFi 2 2.4 GHz WEP 11 Mbps 1
802.11g WiFi 3 2.4 GHz WPA 54 Mbps 1
802.11n WiFi 4 2.4 GHz, 5 GHz WPA2 – PSK, Enterprise ~300 Mbps 4 MIMO
802.11ac WiFi 5 5 GHz WPA3 – PSK, Enterprise ~300 Mbps 8 MU-MIMO, OFDM
802.11ax WiFi 6 2.4 GHz, 5 GHz WPA3 – PSK, Enterprise ~300 Mbps 8 MIMOA, OFDMA
802.11ax WiFi 6e 6 GHz WPA3 – PSK, Enterprise ~300 Mbps 8 MIMOA, OFDMA

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Low power, long range Wi-Fi® for IoT

Authentication and Encryption Standards

These aren’t the same as the WiFi protocol standards above. These standards control how devices authenticate to a WiFi network, and how they encrypt their traffic.

The original WiFi “security” protocol was WEP, so-called “wireless equivalent privacy”. It sucked, and its name was a lie. It used wimpy RC4 stream encryption, and cracking encryption keys was a simple game.

WPA, WiFi Protected Access, was better. It still relied on RC4, but it did the clever trick of changing the encryption key very frequently. By the time you cracked a key, it wasn’t the key anymore. But this just invited a race.

WPA2 moved to AES encryption, with pre-shared key (PSK) and Enterprise (meaning directory login, often involving certificates).

“An Overview of Wireless Protected Access 2 (WPA2)”:

But WPA2 became more susceptible as password hash (key) cracking moved onto ultra-fast GPUs.

Thus came WPA3. Here’s technical details at the Wikipedia level:

And here’s a more friendly PC Magazine article:

“What Is WPA3? More Secure Wi-Fi”: