Section 21: Troubleshooting Wireless Networks

Deauthentication Attack

A common wireless attack used by hackers to disassociate wireless clients and make them attempt to reconnect to the access point

ICMP Redirect

A mechanism by which a router informs a host (like a computer or a server) of a more efficient route for sending packets to a specific destination.

Clear Channel Assessment (cca)

A process used in wireless communication networks to determine if a particular radio channel is free from interference and noise, and thus suitable for transmitting data.

Wrong SSID

A situation in a wireless network where a device attempts to connect to a Wi-Fi network using an incorrect Service Set Identifier (SSID).

Channel Utilization

A statistic or measure of the amount of airtime utilization that occurs for a particular frequency or channel. Keep under 30%

Vertical Antenna

A type of antenna that is oriented vertically and typically radiates radio waves in an omnidirectional pattern along the horizontal plane.

Yagi Antenna

A unidirectional antenna that sends the radio frequency waves in only one direction

dbi

A unit of measurement used to express the gain of an antenna

Captive Portal

A web page displayed to newly-connected Wi-Fi users before being granted broader access to network resources

Parabolic Grid Antenna

Allows the radio waves to be transmitted in only one direction over a longer distance than a Yagi antenna

Received Signal Strength Indication (rssi)

Estimated measure of the power level that a radio frequency client device is receiving from a wireless access point or wireless router

Effective Equivalent Isotropic Radiated Power (eirp)

Maximum power radiated from an ideal isotropic antenna, given its antenna gain, and the transmitter power of the radio frequency system

Coverage

Measure of how much area around a wireless transmitter is there sufficient signal strength for wireless devices to utilize

Interference

Occurs when multiple wireless networks communicate on the same channel using the same frequency 1, 6, 11 on 2.4 to avoid

Authentication Timeout

Occurs when the authentication or key exchange process fails to finish in time

Session Timeout

Occurs when there's no traffic within 1800 seconds

Idle Timeout

Occurs when there's no traffic within 300 seconds

Manual Deletion

Occurs whenever a client is removed by an administrator

Wireless Network Change

Occurs whenever the wireless local area network is changed

Site Survey

Process of planning and designing a wireless network to provide the required wireless solution

Dipole Antenna

Produces radio frequency waves extending outward in two directions

HTTP Redirect

Redirects all traffic to a web server which then redirects them to a captive portal using a 302 HTTP status code

Attenuation

Reduction of signal strength between the transmission and receipt of the signal

Encryption mismatch

Refers to a discrepancy or incompatibility in the encryption protocols used between a wireless device (like a laptop or smartphone) and a wireless access point (like a router). ● Change protocol type ● Disable antivirus tools ● Reinstall drivers

Multipath Reception

Refers to a phenomenon in wireless communication where signal waves arrive at the receiver via multiple paths.

Incorrect Passphrase

Refers to a situation where the password or security key entered to access a Wi-Fi network is wrong.

Access Point Radio Reset

Refers to the process of restarting or resetting the radio component of a wireless access point (AP). This action is typically taken to resolve issues related to the wireless radio functions, such as connectivity problems, poor signal strength, interference, or firmware glitches.

Polarization

The orientation of the electric field (or transmission) from the antenna