Chapter 14 - Wireless Networking

Question 1

What does Wi-Fi stands for?

Answer 1

Wireless Fidelity.

Question 2

What is the IEEE standard for Wi-Fi?

Answer 2

802.11.

Question 3

What is a WAP?

Answer 3

In the context of Wi-Fi, WAP commonly stands for “Wireless Access Point.” A Wireless Access Point is a network device that allows Wi-Fi-enabled devices to connect to a wired network using Wi-Fi. WAPs act as central hubs for wireless communication, providing a bridge between Wi-Fi clients (such as smartphones, laptops, or tablets) and the wired network infrastructure.

Key features of a WAP include:

1. Wireless Connectivity: WAPs enable wireless connectivity by transmitting and receiving Wi-Fi signals.
2. Network Integration: They integrate wireless clients into an existing wired network, allowing seamless communication between wired and wireless devices.
3. SSID (Service Set Identifier) Configuration: WAPs broadcast SSIDs, which are network names that Wi-Fi devices use to identify and connect to a specific wireless network.
4. Security Features: WAPs often include security features such as WPA (Wi-Fi Protected Access) or WPA2 to secure wireless communications.

WAPs are fundamental components of Wi-Fi networks, facilitating wireless connectivity in homes, businesses, and public spaces.

Question 4

What is an ad-hoc wifi network?

Answer 4

An ad-hoc Wi-Fi network is a decentralized wireless network where devices communicate with each other directly rather than through a centralized access point (AP). In an ad-hoc network, devices, such as laptops, smartphones, or tablets, connect with each other without the need for a dedicated router or access point.

Key characteristics of ad-hoc Wi-Fi networks:

1. Peer-to-Peer Communication: Devices in an ad-hoc network communicate directly with each other, forming a peer-to-peer network without relying on a central infrastructure.
2. Dynamic Formation: Ad-hoc networks are typically formed dynamically as devices come into proximity with each other, allowing for spontaneous connections.
3. Limited Range: Ad-hoc networks generally have a limited range compared to infrastructure-based networks, as devices need to be within direct communication range of each other.
4. Flexibility: Ad-hoc networks are flexible and suitable for temporary or ad-hoc situations, such as quick file sharing between devices in a meeting or an impromptu gathering.

Question 5

What does IBSS stands for?

Answer 5

IBSS stands for Independent Basic Service Set. It is a mode of operation for Wi-Fi networks where devices communicate with each other directly in a peer-to-peer fashion without the need for a centralized access point (Ad-hoc). In an IBSS, also known as an ad-hoc network, devices form a basic service set independently, allowing them to connect and communicate with each other dynamically.

Question 6

Define Wi-Fi infrastucture mode.

Answer 6

Wi-Fi infrastructure mode is a standard operating mode in Wi-Fi networks where devices communicate with each other through a central hub or access point (AP). In this mode, the access point serves as the central coordinating device that facilitates communication between Wi-Fi-enabled devices and provides a connection to a wired network, such as the internet.

Key characteristics of Wi-Fi infrastructure mode:
1. Access Point (AP): An access point is a network device that acts as a central hub for Wi-Fi communication. It provides a bridge between Wi-Fi clients and the wired network infrastructure.
2. SSID (Service Set Identifier): The Wi-Fi network is identified by an SSID, which is a network name broadcast by the access point. Wi-Fi-enabled devices connect to the network by selecting the appropriate SSID.
3. Managed Network: Devices in infrastructure mode operate in a managed network, where the access point handles tasks such as channel selection, security, and coordination of communication between devices.
4. Extended Range: Infrastructure mode allows for the creation of larger and more scalable Wi-Fi networks, covering broader areas compared to ad-hoc or peer-to-peer modes.

Wi-Fi infrastructure mode is commonly used in homes, businesses, and public spaces, providing a reliable and scalable solution for wireless connectivity where a centralized access point manages and coordinates communication among connected devices.

Question 7

What are the difference between BSSID, SSID and ESSID?

Answer 7

/BSSID, SSID, and ESSID are terms related to Wi-Fi networks, each serving a specific purpose:

1. BSSID (Basic Service Set Identifier):
   
   • BSSID is a unique identifier assigned to each basic service set (BSS) in a Wi-Fi network.
   • It represents the MAC (Media Access Control) address of the access point (AP) in infrastructure mode or the MAC address of an individual device in ad-hoc mode.
   • BSSID is essential for distinguishing between different access points or devices within a Wi-Fi network.
2. SSID (Service Set Identifier):
   
   • SSID is a text label or name that identifies a Wi-Fi network.
   • It is broadcast by the access point, allowing Wi-Fi-enabled devices to identify and connect to the network.
   • SSID is the human-readable name associated with a BSSID or an ESSID.
3. ESSID (Extended Service Set Identifier):
   
   • ESSID is used in the context of multiple interconnected BSSs to identify a set of interconnected BSSs forming a single logical network.
   • In practical terms, ESSID is often synonymous with SSID in single access point environments, but in multi-AP configurations (like roaming scenarios), it refers to the common SSID shared across multiple access points.

In summary, BSSID is the MAC address of an access point or device, SSID is the human-readable network name, and ESSID is used in more complex setups to identify a set of interconnected BSSs forming a logical network.

Question 8

What is CSMA/CA?

Answer 8

CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) is a protocol used in wireless networks like Wi-Fi (IEEE 802.11). Devices listen to the channel before transmitting to avoid collisions. Unlike wired networks, it can’t detect collisions directly. Instead, it employs virtual carrier sensing and a random backoff algorithm to prevent simultaneous transmissions. This reduces collisions, improving communication efficiency.

Question 9

Give the specifications of IEEE 802.11-1997

Answer 9

2.4 GHz band, DSSS, 2 Mbps, 300 feet.

Question 10

Give the specifications of IEEE 802.11b

Answer 10

2.4 GHz, DSSS, 11 Mbps, 300 feet.

Question 11

Give the specifications of IEEE 802.11a

Answer 11

5.0 GHz, OFDM, 54 Mbps, 150 feet.

Question 12

Give the specifications of IEEE 802.11g

Answer 12

2.4 Ghz, OFDM, 54 Mbps, 300 feet.

Question 13

Give the specifications of IEEE 802.11n

Answer 13

2.4 GHz, OFDM(QAM) on MIMO, 100+ Mbps, 300 feet.

Question 14

Give the specification of IEEE 802.11ac

Answer 14

5 Ghz, OFDM(QAM) on MIMO, Up to 1 Gbps, 300 feet.

Question 15

What is WPS?

Answer 15

WPS, or Wi-Fi Protected Setup, is a network security standard for simplifying device connection to a wireless network. It involves pressing a button or entering a PIN to establish a secure connection without manually entering the Wi-Fi password. However, WPS has known security vulnerabilities, leading to recommendations to disable it for enhanced security.

Question 16

What is EAS?

Answer 16

The Extensible Authentication Protocol (EAP) is an authentication framework commonly used in wireless networks and point-to-point connections. It allows for various authentication methods, including passwords, digital certificates, smart cards, and token-based systems. EAP enables secure communication between a client and an authentication server, facilitating user authentication and network access control.

Question 17

What is 802.1X ?

Answer 17

802.1X is an IEEE standard for network access control that defines the mechanism for port-based authentication. It provides a framework for authenticating and authorizing devices attempting to connect to a LAN or WLAN. 802.1X operates in conjunction with EAP (Extensible Authentication Protocol), allowing for diverse authentication methods such as passwords, digital certificates, and token-based systems. By enforcing authentication before granting network access, 802.1X enhances network security by preventing unauthorized access and ensuring only authenticated devices can connect to the network.

Question 18

What is EAP-PSK?

Answer 18

EAP-PSK (Extensible Authentication Protocol with Pre-Shared Key) is an extension of EAP designed for simple, password-based authentication in wireless networks. It allows devices to authenticate with a pre-shared key (PSK) without the need for certificates or a dedicated authentication server. EAP-PSK is commonly used in small-scale deployments. The most popular form of authentication in modern wireless networks.

Question 19

What is EAP-TLS?

Answer 19

EAP-TLS (Extensible Authentication Protocol-Transport Layer Security) is an authentication protocol commonly used in wireless networks and other network environments. It leverages TLS, a cryptographic protocol, to provide mutual authentication between a client device and an authentication server. Each party presents a digital certificate to verify its identity, ensuring a high level of security. EAP-TLS is often preferred for enterprise networks and environments where strong authentication and encryption are required, as it offers robust protection against various attacks, including man-in-the-middle attacks.

Question 20

What is EAP-TTLS?

Answer 20

EAP-TTLS (Extensible Authentication Protocol-Tunneled Transport Layer Security) is an extension of EAP designed to provide secure authentication for wireless and wired networks. It encapsulates the authentication process within a TLS tunnel, allowing for various authentication methods within the tunnel, including passwords, digital certificates, and token-based systems. EAP-TTLS is particularly useful in environments where legacy authentication methods are still in use or where deploying client certificates is impractical. It provides a flexible and secure way to authenticate users and devices while protecting sensitive authentication information.

Question 21

What is EAP-MS-CHAPv2?

Answer 21

EAP-MS-CHAPv2 (Extensible Authentication Protocol with Microsoft Challenge Handshake Authentication Protocol version 2) is an authentication protocol commonly used in Microsoft Windows environments. It allows devices to authenticate with a central server using a username and password. EAP-MS-CHAPv2 provides a secure method for authenticating users over a network, encrypting the authentication process to prevent eavesdropping and replay attacks. While widely supported in Windows-based networks, EAP-MS-CHAPv2 has some security concerns, particularly regarding the storage and transmission of password hashes, which can potentially be cracked through brute-force attacks.

Question 22

What is WEP?

Answer 22

WEP (Wired Equivalent Privacy) is a security protocol used to protect wireless networks. It was introduced as part of the original IEEE 802.11 standard to provide data confidentiality by encrypting wireless data transmissions. WEP uses a shared key encryption mechanism, where all devices on the network share the same encryption key. However, WEP has serious security flaws that make it vulnerable to various attacks, including key recovery attacks and packet injection attacks. Due to these vulnerabilities, WEP is no longer considered secure and has largely been replaced by more robust security protocols such as WPA and WPA2.

Question 23

What is WPA2?

Answer 23

WPA2 (Wi-Fi Protected Access 2) is a security protocol used to secure wireless networks. It builds upon the earlier WPA (Wi-Fi Protected Access) standard and provides stronger security features. WPA2 uses the AES (Advanced Encryption Standard) encryption algorithm, which is more robust than the TKIP (Temporal Key Integrity Protocol) encryption used in WPA. It also supports stronger authentication methods, including EAP (Extensible Authentication Protocol) for enterprise environments.

WPA2 offers two modes of operation: Personal (WPA2-PSK) and Enterprise. WPA2-Personal uses a pre-shared key (PSK) for authentication, while WPA2-Enterprise employs a RADIUS server for centralized authentication and key management.

WPA2 is widely used and considered secure when configured correctly with a strong passphrase or proper authentication mechanisms. However, vulnerabilities such as KRACK (Key Reinstallation Attack) have been discovered in certain implementations, emphasizing the importance of keeping devices and firmware updated to mitigate potential security risks.

Question 24

What is TKIP?

Answer 24

TKIP (Temporal Key Integrity Protocol) is a cryptographic protocol used in wireless networks to provide data confidentiality and integrity. It was introduced as part of the original WPA (Wi-Fi Protected Access) standard as a replacement for the insecure WEP (Wired Equivalent Privacy) protocol.

TKIP operates by dynamically generating unique encryption keys for each data packet transmitted over the network. It also incorporates a message integrity check (MIC) to detect and reject tampered or forged packets.

While TKIP represented a significant improvement over WEP, it has since been superseded by the more secure AES (Advanced Encryption Standard) encryption algorithm in WPA2 (Wi-Fi Protected Access 2) and later security protocols. Despite its initial security enhancements, TKIP has known vulnerabilities and is no longer recommended for use in secure wireless networks.

Question 25

Which wireless networking technologies used the 5.0 Ghz frequency range?

Answer 25

802.11a and 801.11ab.

Question 26

Which technology enables the use of WAP without directly connecting the WAP to an AC power outlet?

Answer 26

PoE.

Question 27

What feature enables 802.11n to minimize deadspot?

Answer 27

Transit beamforming.