S7-Wireless Networks Flashcards
What is an Ad Hoc network?
Also known as and Independent Basic Service Set (IBSS)
Network where devices connect directly to each other.
- isolated, doesn’t typically provide internet access
- allows for sharing and collaboration between devices w/o a central AP so long as the devices are within range.
Infrastructure Wireless Network
More Organized setup in which wireless devices are bridged to a wired LAN through a Wireless AP.
what is a BSSID?
“Basic service set identifier”
Unique identifier for a wireless access point that is set to the MAC address of the AP.
What is the SSID?
“Service Set identifier”
Common Alphanumeric network name
What is ESS?
“Extended Service Set”
is a group of interconnected Basic Service Sets (BSS) that appear as a single, seamless wireless network that shares the same SSID to allow for seamless connectivity across a building.
What is a BSS?
“Basic Service Set”
basic building block of a wireless network, consisting of a wireless access point (AP) and the wireless devices (stations) connected to it.
Point-to-point Wireless networks
Network type that connects 2 distinct locations over long distances using high-gain antennas
Wireless Mesh Networks
Versatile and resilient form of wireless networking where each node in the network connects to multiple other nodes providing potentially infinite paths for data to travel (Self-Healing capability).
Autonomous AP
Standalone device that handles all wireless networking functions independently
Lightweight AP
Multiple access points that connect back to a centralized controller
Wireless Antenna
Devices that send and receive radio frequency signals
Omni Directional Antennas
Transmit and receive wireless signals in all directions equally
- good for broad area applications
- think Embedded devices
Unidirectional Antennas
Focuses on a single direction to provide a more concentrated signal beam
- Provides a direct wireless point to point connection
Yagi Antennas
Type of directional antenna that can provide high signal gains and uses a narrow beam width
- good for long distance applications
Parabolic Antenna
Special type of unidirectional antenna that features a different curvature to the signal and is used with microwave signals and satellite TV signals.
- curved, dish shaped antenna.
what are the 3 frequency bands used?
- 2.4 GHz
- 5 GHz
- 6 GHz
2.4 GHz Band qualities
- slower speeds
- less bandwidth
- less channels
- more channel interference
- better distance & object penetration
What is a Channel
Physical medium through which the wireless networks can send and receive data.
- virtual cable
What are the main 2.4GHz Channels?
11, 13, 14
Which channels do not overlap within the 2.4 GHz band?
1, 6, 11
How much bandwidth does the 2.4 GHz band support and how much is allotted to each channel?
- 72 MHz bandwidth
- 22MHz per channel
What is the Global channel availability for the 2.4GHz band?
US & Canada
- 1 to 11
Japan
- 1 to 14
Rest
- 1 to 13
5GHz Band Qualities
- Faster Speeds
- More Bandwidth
- More channels
- Less distance & weaker object penetration
- can support wider channels through channel bonding
Channel Bonding
Merging 2 or more neighboring channels into a single wider channel
6 GHz Band Qualities
- Fastest Speeds
- highest bandwidth
- most channels
- shortest distance
- least object penetration
what frequencies are contained within the 6 GHz Band?
from 5.925 to 7.125 GHz
what frequencies are contained within the 5 GHz Band?
from 5.725 to 5.875 GHz
what frequencies are contained within the 2.4 GHz Band?
from 2.4 to 2.495 GHz
How much bandwidth is allocated to the 6GHz band?
1200 MHz Bandwidth
What are the possible channel bandwidth sizes within the 6 GHz range?
20 MHz (59 channels)
40 MHz
80 MHz
160 MHz (7 channels)
Why was the 802.11h standard developed?
minimize interference with other services, such as radar and satellite communication.
What are some key features of the 802.11h standard?
- Dynamic Frequency Selection (DFS)
- Transmit Power Control (TPC)
What is Dynamic Frequency Selection (DFS)?
Feature the requires devices to monitor the environment for radar signals
What is Transmit Power Control (TPC)?
Allows devices to adjust their transmitting power to the minimum required for maintaining a good connection.
What is Band Steering?
Wireless Networking Tech that Optimizes the distribution of client devices across different frequency bands
When is Band Steering Relevant?
relevant in environments where 2 or more bands are being used by networking equipment and clients
Wireless a (802.11a) Details
- 5GHz Band
- 54Mbps speed
- 35m range
Wireless b (802.11b) Details
- 2.4GHz Band
- 11Mbps Speed
- 140m range
Wireless g (802.11g) Details
- 2.4Ghz Band
- 54Mbps speed
-140m range
Wireless n (802.11n) Details
WIFI 4
- 5GHz Band
- 600Mbps speed
- 35m Range
Hybrid WIFI 4 devices
- 2.4GHz & 5GHz bands
- 300Mbps speed (2.4GHz)
- 70m range (2.4GHz)
- backwards compatible
what is MIMO?
“Multi - Input , Multi - Output”
Technology that allows an AP to use multiple antennas to send and receive data at faster speeds
Wireless ac (802,11ac)
WIFI 5
- 5GHz Band
- 6.9+ Gbps speeds
- not backwards compatible
What is MU - MIMO
Multi - User
Multi - Input
Multi - Output
Multipath wireless communication tech that allows multiple users to access the wireless network and AP at the same time
what’s the difference between the network characteristics of a MIMO and MU-MIMO?
MIMO
- network acts like a hub
MU-MIMO
- network acts like a switch
Wireless ax (802.11ax) Details
WIFI 6
- 2.4, 5 GHz Bands
- up to 9.6Gbps speeds
- uses MU-MIMO
WIFI 6e
- 2.4, 5, 6 GHz Bands
Which Standards support which bands?
2.4GHz
-b, g, n, ax
5GHz
- a, n, ac, ax
6GHz
- ax
What are the 2 wireless security mechanisms?
- Pre-shared Key
- Enterprise Auth. System
what is a Pre-Shared Key (PSK)?
Authentication type where the same key is used on the wireless AP and any connecting client devices trying to access the network.
What is 802.1X?
widely used Enterprise-grade Authentication Method that relies on an Authentication server (RADIUS)
What are the Security and encryption options used on wireless networks
- WEP
- WPA
- WPA2
- WPA3
- WPS
What is WEP?
“Wired Equivalent Privacy”
Original 802.11 wireless security standard. Insecure
- uses Pre-Shared key
- uses Rivest Cipher 4 (RC4) encryption
- Uses 24-bit Initialization Vector(IV)
what is an initialization Vector (IV)?
A 24-bit, pseudo-random value used to introduce randomness into the encryption process, even when the same key is used multiple times.
WPA features
“WIFI Protected Access”
Replacement for WEP that uses the
- Temporal Key Integrity Protocol (TKIP)
- message integrity check
- enterprise mode
What is TKIP?
“Temporal Key Integrity Protocol”
48-bit encryption protocol used with WPA that dynamically changes encryption keys and includes a message integrity check.
- insecure
what is a MIC?
“Message integrity Check”
check that hashes data before its sent over the network
WPA2 Features
- CCMP ( Countermode with cipher block chaining and message authentication code protocol)
- AES (Advanced Encryption standard)
- Personal Mode
- Enterprise Mode
what is AES?
“Advanced Encryption standard”
Encryption standard that replaced the older RC4 standard that offers more data security and confidentiality
- 128-bit, 192-bit, 256-bit key
what is Enterprise mode?
Authentication type that features individual user credentials and a centralized authentication method.
WPA3 features
- SAE (simultaneous auth. of equals)
- AES - GCM(Galois/Counter Mode)
- allows larger 192-bit & 256-bit encryption keys
what is SAE
“simultaneous auth. of equals”
Security protocol that enhances the handshake process used in WIFI authentication
- replaces the Pre-Shared key
- uses a protocol based on the dragonfly key exchange methods that better protects against dictionary attacks
What is WIFI Protected Setup (WPS)?
Network Security Standard aimed at simplifying the setup of a secure WIFI connection
- allows users to connect using a 8 digit pin setup via push button or NFC
- insecure
What is a Captive Portal?
Feature on guest access networks that intercepts a user’s network connection and directs them to a webpage for authentication.
Functions of a Captive Portal?
- User Auth.
- User Experience
- Policy acceptance
- Data collection
- Guest network control
- Maintain guest network security
- Branding & Marketing
