Wireless Standards and Security
Two things get tested: which 802.11 standard fits a speed and band requirement, and which security protocol to use. The channel table matters because non-overlapping channels are a recurring troubleshooting answer.
Wireless Standards and Security · firsttry.app/cheatsheets/wireless-standards · original reference written from published exam objectives. Not affiliated with any certification body.
802.11 standards
| Standard | Wi-Fi name | Band | Max theoretical speed |
|---|---|---|---|
| 802.11a | 5 GHz | 54 Mbps | |
| 802.11b | 2.4 GHz | 11 Mbps | |
| 802.11g | 2.4 GHz | 54 Mbps | |
| 802.11n | Wi-Fi 4 | 2.4 and 5 GHz | 600 Mbps |
| 802.11ac | Wi-Fi 5 | 5 GHz | 6.9 Gbps |
| 802.11ax | Wi-Fi 6 | 2.4 and 5 GHz | 9.6 Gbps |
| 802.11ax | Wi-Fi 6E | 6 GHz added | 9.6 Gbps |
| 802.11be | Wi-Fi 7 | 2.4, 5 and 6 GHz | 46 Gbps |
Bands and channels
| Band | Property | Detail |
|---|---|---|
| 2.4 GHz | Range | Better range, penetrates walls |
| 2.4 GHz | Non-overlapping channels | 1, 6, 11 |
| 2.4 GHz | Interference | Microwaves, Bluetooth, cordless phones |
| 5 GHz | Range | Shorter range, more channels |
| 5 GHz | Channels | Many non-overlapping, some need DFS |
| 6 GHz | Range | Shortest range, least congestion |
| Channel width | Trade-off | Wider is faster and more interference-prone |
Wireless security
| Protocol | Encryption | Status |
|---|---|---|
| WEP | RC4, static key | Broken. Crackable in minutes |
| WPA | TKIP with RC4 | Deprecated |
| WPA2-Personal | AES-CCMP, pre-shared key | Acceptable, PSK is the weak point |
| WPA2-Enterprise | AES-CCMP with 802.1X | Per-user credentials via RADIUS |
| WPA3-Personal | AES with SAE | Current. SAE resists offline cracking |
| WPA3-Enterprise | AES-GCMP with 802.1X | Current, 192-bit mode available |
| WPS | Not encryption | PIN is brute-forceable. Disable it |
| Captive portal | Not encryption | Authentication page, no link security |
Exams covered
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