ShadowMyGeekSpace
May 21st, 2006, 09:47 AM
(EMW) Wireless Networking (WiFi)
WiFi is more commonly known as "Wireless Networking" is covered by the IEEE 802.11 Specifications (http://grouper.ieee.org/groups/802/11/), and reside on the 2.4 and 5ghz frequencies. Due to the lack of implementation(and lack of knowledge on my part) for the 5ghz standard (802.11a), that will not be covered.
Frequencies and Channels
802.11b and 802.11g share the same frequencies in the 2.4ghz(12.5cm wave length) range. The channels for 802.11b and g are overlapping channels with the center frequencies set ~5MHz apart. The spectral mask for 802.11x is attenuated by 30+ dB from it's peak strength at ±11Mhz from the center, and 50+dB from peak at ±22MHz
Channel 1 - 2.412 GHz
Channel 2 - 2.417 GHz
Channel 3 - 2.422 GHz
Channel 4 - 2.427 GHz
Channel 5 - 2.432 GHz
Channel 6 - 2.437 GHz**
Channel 7 - 2.442 GHz
Channel 8 - 2.447 GHz
Channel 9 - 2.452 GHz*
Channel 10 - 2.457 GHz*
Channel 11 - 2.462 GHz**
Channel 12 - 2.467 GHz
Channel 13 - 2.472 GHz
Channel 14 - 2.484 GHz
Only channels 1-11 can be used in North America (without modifying drivers or hardware) legally. Channels 1-13 are legal in Europe, and all channels are legal in Japan.
* Microwave ovens operate on ~2.45GHz, so they wreck havoc on communications through all channels, most notably on channels 8 to 11. As WiFi shares these frequency ranges, signal strength can vary, and is influenced by humidity due to the fact that 2.4ghz RF is absorbed by water through dielectric heating.
** Channel 6 and 11 are the default frequencies for most WiFi networking equipment. It is recommended that you change to a separate channel to avoid degraded performance.
802.11b
802.11b has a maximum raw throughput of 11 megabits per second, and scales back to 5.5, 2, and 1Mbit/s depending on signal strength. Devices may receive burstable bandwidth of up to 44Mbps. The actual bandwidth offered after protocol overhead(CSMA/CA) is ~6mbit over TCP and ~7mbit over UDP at it's 11Mbit data rate. The modulation technique used for 802.11b products is CCK, a slight variation of CDMA.
802.11g
802.11g has a maximum raw throughput of 54mbits per second, and scales back to 48, 36, 24, 18, 12, 11, 9, 6, 5.5, 2, and 1Mbit/s depending on signal strength. Proprietary technology exists to get the throughput up to 125Mbit/s, for more info google "Speedbooster." The actual bandwidth offered after protocol overhead is 24.7Mbit/s for TCP or 30.4Mbit/s for UDP, at the 54Mbit data rate. The modulation technique used for 802.11g is OFDM for the 6, 9, 12, 18, 24, 36, 48, and 54Mbit rates. The 802.11b speeds are modulated using the 802.11 method, CCK.
Some quick security info
SSID: An SSID is the "network name" for a wireless network. Vendors usually default to their name, such as Linksys's products having the default SSID of "Linksys". Disabling "SSID Broadcast" removes the SSID from the Beacon Frame, making it impossible for the average sheeple to connect to your wireless network. The SSID can still be collected from your network with the correct tools, such as ethereal (http://ethereal.com).
MAC Filtering: Most equipment allows you to add MAC addresses to the authorized device list kept on some access points/routers. If a MAC address isn't on the list, it doesn't recieve any acknowledgements from the access point/router when it requests access. Anyone with a basic network analyzer such as Ethereal (http://www.ethereal.com), ettercap (http://ettercap.sf.net), or Cain and Abel (http://www.oxid.it/cain.html) and knowledge of configuring a network device will beable to bypass this by sniffing and spoofing an authorized device's MAC address.
WEP: Short for "Wired Equivalent Privacy", WEP is an insecure encryption solution for wireless, meant to keep other clients off of your wireless network, and to stop them from sniffing your data, using an RC4 cipher that has a few issues. Several tools are available to crack WEP encryption, such as Airsnort, (http://airsnort.sf.net) WEPcrack, (http://wepcrack.sf.net) Aircrack, (http://freshmeat.net/projects/aircrack/) and Kismet (http://www.kismetwireless.net/) (These are not the only ones, simply the most popular) For more info, see http://en.wikipedia.org/wiki/Wired_Equivalent_Privacy
WPA: Short for "Wi-Fi Protected Access", WPA is a semi-secure encryption solution for wireless networks, using the RC4 cipher. Aircrack will break WPA. For more info, see http://en.wikipedia.org/wiki/Wi-Fi_Protected_Access
WPA-2: Also known as 802.11i, WPA-2 is the most secure encryption solution for wireless networks introduced yet as far as I know, using the AES encryption cipher rather than the RC4 encryption cipher. For more info see http://en.wikipedia.org/wiki/IEEE_802.11
---
If any errors are found in the above post, please contact me. If any questions exist, please contact me. And more important, if you think your lawn gnomes may be hacking your Wifi, please contact me.
WiFi is more commonly known as "Wireless Networking" is covered by the IEEE 802.11 Specifications (http://grouper.ieee.org/groups/802/11/), and reside on the 2.4 and 5ghz frequencies. Due to the lack of implementation(and lack of knowledge on my part) for the 5ghz standard (802.11a), that will not be covered.
Frequencies and Channels
802.11b and 802.11g share the same frequencies in the 2.4ghz(12.5cm wave length) range. The channels for 802.11b and g are overlapping channels with the center frequencies set ~5MHz apart. The spectral mask for 802.11x is attenuated by 30+ dB from it's peak strength at ±11Mhz from the center, and 50+dB from peak at ±22MHz
Channel 1 - 2.412 GHz
Channel 2 - 2.417 GHz
Channel 3 - 2.422 GHz
Channel 4 - 2.427 GHz
Channel 5 - 2.432 GHz
Channel 6 - 2.437 GHz**
Channel 7 - 2.442 GHz
Channel 8 - 2.447 GHz
Channel 9 - 2.452 GHz*
Channel 10 - 2.457 GHz*
Channel 11 - 2.462 GHz**
Channel 12 - 2.467 GHz
Channel 13 - 2.472 GHz
Channel 14 - 2.484 GHz
Only channels 1-11 can be used in North America (without modifying drivers or hardware) legally. Channels 1-13 are legal in Europe, and all channels are legal in Japan.
* Microwave ovens operate on ~2.45GHz, so they wreck havoc on communications through all channels, most notably on channels 8 to 11. As WiFi shares these frequency ranges, signal strength can vary, and is influenced by humidity due to the fact that 2.4ghz RF is absorbed by water through dielectric heating.
** Channel 6 and 11 are the default frequencies for most WiFi networking equipment. It is recommended that you change to a separate channel to avoid degraded performance.
802.11b
802.11b has a maximum raw throughput of 11 megabits per second, and scales back to 5.5, 2, and 1Mbit/s depending on signal strength. Devices may receive burstable bandwidth of up to 44Mbps. The actual bandwidth offered after protocol overhead(CSMA/CA) is ~6mbit over TCP and ~7mbit over UDP at it's 11Mbit data rate. The modulation technique used for 802.11b products is CCK, a slight variation of CDMA.
802.11g
802.11g has a maximum raw throughput of 54mbits per second, and scales back to 48, 36, 24, 18, 12, 11, 9, 6, 5.5, 2, and 1Mbit/s depending on signal strength. Proprietary technology exists to get the throughput up to 125Mbit/s, for more info google "Speedbooster." The actual bandwidth offered after protocol overhead is 24.7Mbit/s for TCP or 30.4Mbit/s for UDP, at the 54Mbit data rate. The modulation technique used for 802.11g is OFDM for the 6, 9, 12, 18, 24, 36, 48, and 54Mbit rates. The 802.11b speeds are modulated using the 802.11 method, CCK.
Some quick security info
SSID: An SSID is the "network name" for a wireless network. Vendors usually default to their name, such as Linksys's products having the default SSID of "Linksys". Disabling "SSID Broadcast" removes the SSID from the Beacon Frame, making it impossible for the average sheeple to connect to your wireless network. The SSID can still be collected from your network with the correct tools, such as ethereal (http://ethereal.com).
MAC Filtering: Most equipment allows you to add MAC addresses to the authorized device list kept on some access points/routers. If a MAC address isn't on the list, it doesn't recieve any acknowledgements from the access point/router when it requests access. Anyone with a basic network analyzer such as Ethereal (http://www.ethereal.com), ettercap (http://ettercap.sf.net), or Cain and Abel (http://www.oxid.it/cain.html) and knowledge of configuring a network device will beable to bypass this by sniffing and spoofing an authorized device's MAC address.
WEP: Short for "Wired Equivalent Privacy", WEP is an insecure encryption solution for wireless, meant to keep other clients off of your wireless network, and to stop them from sniffing your data, using an RC4 cipher that has a few issues. Several tools are available to crack WEP encryption, such as Airsnort, (http://airsnort.sf.net) WEPcrack, (http://wepcrack.sf.net) Aircrack, (http://freshmeat.net/projects/aircrack/) and Kismet (http://www.kismetwireless.net/) (These are not the only ones, simply the most popular) For more info, see http://en.wikipedia.org/wiki/Wired_Equivalent_Privacy
WPA: Short for "Wi-Fi Protected Access", WPA is a semi-secure encryption solution for wireless networks, using the RC4 cipher. Aircrack will break WPA. For more info, see http://en.wikipedia.org/wiki/Wi-Fi_Protected_Access
WPA-2: Also known as 802.11i, WPA-2 is the most secure encryption solution for wireless networks introduced yet as far as I know, using the AES encryption cipher rather than the RC4 encryption cipher. For more info see http://en.wikipedia.org/wiki/IEEE_802.11
---
If any errors are found in the above post, please contact me. If any questions exist, please contact me. And more important, if you think your lawn gnomes may be hacking your Wifi, please contact me.