2.3 Wireless Technologies, Wireless Networking, Network Types, and Wireless Encryption

What are the different parts of 802.11 technologies?

Frequencies– 2.4 GHz, 5 GHz, and 6 GHz

Channels– Groups of frequencies, numbered by the IEEE– Using non-overlapping channels would be optimal

Bandwidth– Amount of frequency in use– 20 MHz, 40 MHz, 80 MHz, 160 MHz

What is Band Steering?

Directing clients/Admin determining the best frequency

What is the 802.11h standard?

Worldwide standard of frequency allocation

What is Dynamic Frequency Selection (DFS)?

Access point can switch to an unused frequency to avoid frequency conflicts

What is Transmit Power Control (TPC)?

Avoid satellite services conflict

Access point determines power output of the client

What is Independent basic service set (IBSS)?

When two devices are connected directly using 802.11 (w/o an access point)

aka ad hoc

What is Ad Hoc?

Device to device connection

What is Service Set Identifier (SSID)?

wireless network name - multiple devices can have the same name

What is Basic Service Set Identifier (BSSID)?

Hardware address of an access point

How to tell the difference between multiple access points under the same SSID

What is an Extended Service Set Identifier?

network name shared across access points

Used for smooth connection transfer even when moving

What is Captive Portal?

Where you login in to authenticate to a network (usernames and passwords)

Access table recognizes a lack of authentication and direct web access to captive portal page

What are Wireless security modes

Open System - no authentication password required

WPA/2/3-Personal (PSK)– WPA2/3 with a pre-shared key– Everyone uses the same 256-bit key - ex. coffee shop wifi password

WPA/2/3-Enterprise / WPA/2/3-802.1X– Authenticates users individually with an authentication server - ex. indiv. username/password

What are Omnidirectional antennas?

Most common antennas

Signal is evenly distributed on all sides

Advantage: coverage in all directions =good choice for most environments

Disadvantage: No ability to focus the signal w/o a different antenna

What are Directional antennas?

Focus signal for increased distances

Can only send and receive in a single direction

Measured in decibel (dB) - doubles in power every 3dB gained

How to manage wireless configurations?

Autonomous access points – access point handles most wireless tasks, switch is not wireless-aware

Lightweight access points – intelligence is in the switch - Less expensive

Control and provision –CAPWAP is an RFC standard that Manage multiple access points simultaneously

What are wireless LAN controllers?

“Pane of Glass” - central managment of access points

Deploy new access points

Performance and security monitoring
Configure and deploy changes to all sites

Report on access point use

What are the Network types?

Mesh

Ad Hoc Mode

Point to point mode

Infrastructure mode

What is wireless mesh?

type of network that has multiple access or devices attached to each other

What is ad hoc mode?

type of network that is device to device connection without access points

What is point to point mode?

Type of network that connects two access points together

good for distance

may require specialized equipment

what is infrastructure mode?

Type of network that has a central access point.

Clients communicate to an access point –Access point forwards traffic

Clients can communicate to a wired network –Access point bridges the networks

Clients can communicate to each other –If the access point allows

How to secure a wireless network?

Authenticates users before granting access, encrypts wireless data, verify the integrity of all communications (Message integrity check (MCI))

Do we use Wired Equivalent Privacy or Wi-Fi Protected Access?

Only use Wi-Fi Protected Access

WEP had cryptographic weaknesses

What is Wi-Fi Protected Access 2 (WPA2) and CCMP block cipher mode?

CCMP combines encryption with integrity in same protocol

AES is encryption

Message Integrity Check is Counter Mode with Cipher Block Chaining Message Authentication Code (CBC-MAC)