Wireless LAN and Wi-Fi Basics

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Questions and Answers

What frequency band does microwave transmission in WLAN products typically operate at?

5.725 GHz

2.4 GHz

18 GHz (correct)

900 MHz

Which method does spread spectrum transmission NOT utilize?

Packet switching (correct)

Frequency hopping

Code Division Multiple Access

Direct sequence modulation

In frequency hopping, what does the transmitter do if it detects that a channel is full?

Transmits at a lower power level

Stops all transmission

Continues to transmit until interrupted

Hops to another channel (correct)

What is the purpose of the code transmitted with each signal in Direct Sequence Modulation?

To identify the appropriate signal for the receiver Signup and view all the answers

Which of the following describes directed infrared transmission?

Infrared light is focused to increase transmission speed Signup and view all the answers

What is the highest transmission speed achieved in infrared transmission methods?

Directed point-to-point infrared transmission Signup and view all the answers

Which component is NOT part of the IEEE 802.11 WLAN architecture?

Core Network Switch Signup and view all the answers

What is the ISM band reserved for?

Industrial, scientific, and medical devices Signup and view all the answers

What is the main function of the BSS Master in a WLAN setup?

To connect wireless clients to a wired LAN Signup and view all the answers

What is necessary for BSS Clients to connect to a BSS?

The same SSID Signup and view all the answers

What does an Extended Service Set (ESS) require for its BSSs?

A common service set identifier Signup and view all the answers

Which technology allows a distribution system to connect access points in an ESS?

WDS (Wireless Distribution System) or MESH protocols Signup and view all the answers

What happens to BSSs in an Extended Service Set from the perspective of the Logical Link Control layer?

They appear as a single BSS Signup and view all the answers

In what type of environment can WLANs be used according to the provided information?

From small home networks to large mobile networks Signup and view all the answers

What is one characteristic of the Service Set Identity (SSID)?

It must be between 2 and 32 alphanumeric characters Signup and view all the answers

Which best describes a wireless LAN hotspot?

A public access point often requiring no password Signup and view all the answers

Which wireless LAN standard operates at a frequency of 5.0 GHz?

802.11a Signup and view all the answers

What is the primary concern regarding security in wireless LANs compared to wired LANs?

They use a more open medium for communication. Signup and view all the answers

Which wireless LAN standard is considered obsolete due to its low performance?

802.11 Signup and view all the answers

Which wireless LAN standard provides a performance of 108 Mbps but is not yet finalized?

802.11n Signup and view all the answers

What is one of the significant issues with wireless LANs as mentioned in the content?

They are affected by interference from other devices. Signup and view all the answers

What is one primary reason administrators should be vigilant with wireless networks?

To prevent unauthorized access Signup and view all the answers

Which encryption standard should generally be avoided due to its numerous flaws?

WEP Signup and view all the answers

Which of the following WLAN standards supports longer distances up to kilometers?

802.16d Signup and view all the answers

How does WPA enhance security compared to WEP?

By employing a per-packet key Signup and view all the answers

What is a common feature of Access Points (APs) in wireless networks?

They create hot spot areas for wireless coverage. Signup and view all the answers

Which wireless LAN standard combines the features of previous standards but is more costly?

802.11g Signup and view all the answers

What common feature is shared by both WPA and WPA2?

Wireless network certification by the Wi-Fi Alliance Signup and view all the answers

What does TKIP stand for in relation to the WPA protocol?

Temporary Key Integrity Protocol Signup and view all the answers

What is a drawback of the WEP encryption method?

It employs static encryption keys Signup and view all the answers

Which of the following describes WPA2 in terms of security?

Supports the same protocols as WPA Signup and view all the answers

Which key management approach distinguishes WPA from WEP?

Dynamic key generation for each data packet Signup and view all the answers

What is the main flaw of CRC in comparison to Michael?

CRC provides weaker data integrity guarantees. Signup and view all the answers

Which encryption mode is introduced by WPA2 for enhanced security?

CCMP Signup and view all the answers

What security measure is considered the first step towards securing a wireless network?

Disabling SSID broadcasting. Signup and view all the answers

Why is changing the default IP, username, and password on Access Points (APs) important?

To prevent unauthorized access. Signup and view all the answers

What is the primary purpose of MAC filtering in wireless security?

To prevent unauthorized access by specifying authorized MAC addresses Signup and view all the answers

Which of the following can help prevent unauthorized access to a network?

Configuring a firewall on access points Signup and view all the answers

What issue may arise from leaving the DHCP service enabled on an Access Point?

It allows unauthorized users access. Signup and view all the answers

Why should users avoid making important data transactions on public hotspots?

Public hotspots typically do not implement any security measures Signup and view all the answers

What characterizes the MAC address in networking?

It is a unique hardware address of 48 bits. Signup and view all the answers

Which aspect of WPA is notably weaker than that of WPA2?

The message integrity check algorithm. Signup and view all the answers

What should a user verify before using a public Wi-Fi network for sensitive transactions?

The legitimacy of the hotspot Signup and view all the answers

What is a key benefit of Wi-MAX technology?

It provides high-speed broadband over long distances without cables Signup and view all the answers

How frequently should AP passwords ideally be changed?

Every month. Signup and view all the answers

What is the IEEE standard associated with Wi-MAX technology?

IEEE 802.16 Signup and view all the answers

Which of the following actions can enhance wireless network security for users?

Using strong and complex passwords for the network Signup and view all the answers

What does the WiMAX Forum aim to promote?

Interoperability and conformity of WiMAX standards Signup and view all the answers

What is the main flaw of the WEP encryption standard?

It is vulnerable to numerous known exploits. Signup and view all the answers

Which encryption method provides the strongest security for wireless networks?

WPA2 Signup and view all the answers

How does WPA achieve better security compared to WEP?

Through the implementation of per-packet key generation. Signup and view all the answers

What is a characteristic feature of WPA and WPA2 protocols?

They enable dynamic key generation per data packet. Signup and view all the answers

What distinguishes Wi-Fi from traditional wireless technologies?

Wi-Fi supports high speed data communication via wireless protocols. Signup and view all the answers

What role does an access point serve in a WLAN?

It acts as a central transmitter and receiver of WLAN signals. Signup and view all the answers

Which component of WPA helps prevent attackers from altering data packets?

Message Integrity Check Signup and view all the answers

What is the primary reason to choose WPA2 over WPA?

WPA2 supports enhanced encryption methods. Signup and view all the answers

Which statement accurately reflects the function of the IEEE 802.11 protocol?

It uses Carrier Sense Multiple Access with Collision Avoidance for data handling. Signup and view all the answers

Which of the following best describes the Wireless Application Protocol (WAP)?

WAP defines a network architecture for content delivery across multiple wireless technologies. Signup and view all the answers

Which aspect of wireless network security is recommended for all devices on the network?

Using the same encryption scheme and password across devices. Signup and view all the answers

What is a common misconception about WEP?

It provides strong encryption comparable to wired networks. Signup and view all the answers

What is a primary principle behind the CSMA/CA protocol used in IEEE 802.11?

It requires devices to listen for signals before transmitting to avoid collisions. Signup and view all the answers

Which characteristic differentiates the WLAN from traditional LAN setups?

WLANs enable users to remain connected while moving within a limited area. Signup and view all the answers

What is a significant risk associated with using public Wi-Fi networks?

Users may inadvertently expose sensitive data to unauthorized parties. Signup and view all the answers

Which of the following characterizes the primary function of MAC filtering in WLAN security?

To allow only specific devices to connect to the network. Signup and view all the answers

Which wireless LAN standard is NOT prominently used due to its performance limitations?

802.11h & j Signup and view all the answers

What key challenge does wireless LAN security face compared to wired LANs?

Limited physical access control Signup and view all the answers

Which characteristic distinguishes the 802.11g standard from other WLAN standards?

It combines features of previous standards but is the least cost-effective. Signup and view all the answers

Which factor significantly impacts the stability of wireless networks?

Interference from other wireless devices Signup and view all the answers

What is the main advantage of using MAC filtering in network security?

It prevents unauthorized devices from accessing the network. Signup and view all the answers

What is the bandwidth of the 802.11a wireless LAN standard?

54 Mbps Signup and view all the answers

Which encryption protocol is known for its numerous vulnerabilities and should generally be avoided?

Wired Equivalent Privacy (WEP) Signup and view all the answers

What is a primary security risk associated with Access Points (APs) in wireless networks?

They can allow unauthorized access to the network. Signup and view all the answers

Why is it advised not to use public hotspots for sensitive transactions?

Public hotspots often lack encryption and security measures. Signup and view all the answers

Which standard should generally be avoided for wireless security due to its flaws?

WEP Signup and view all the answers

What defines Wi-MAX technology in terms of its capability?

It can provide broadband speeds up to 10 Mbps over long distances. Signup and view all the answers

In terms of performance, which wireless LAN standard is considered obsolete?

802.11b Signup and view all the answers

Which of the following actions can help prevent unauthorized access to a wireless network?

Regularly changing your AP passwords. Signup and view all the answers

What essential verification should a user perform before engaging in sensitive transactions on a public Wi-Fi network?

Verify the legitimacy of the hotspot being used. Signup and view all the answers

Which feature is typically emphasized in firewall settings for enhanced security in access points?

Blocking unauthorized external access to local services. Signup and view all the answers

What transmission mode does Wi-MAX technology utilize for its long-range network capability?

Point-to-multipoint connections. Signup and view all the answers

What is the primary reason for implementing CCMP in WPA2?

To enhance encryption strength using AES Signup and view all the answers

How does disabling SSID broadcasting contribute to wireless security?

It reduces the likelihood of detection by casual attackers Signup and view all the answers

What is a significant flaw associated with the Michael algorithm used in WPA?

It allows key recovery through packet analysis Signup and view all the answers

Which security measure should be taken regarding DHCP services in Access Points?

DHCP should be disabled to prevent unauthorized access Signup and view all the answers

What is the primary reason for regularly changing the default password of an Access Point (AP)?

To prevent brute-force attacks from automated tools Signup and view all the answers

Why is it critical to implement strong encryption when providing public access to a wireless network?

To protect sensitive information from unauthorized access Signup and view all the answers

What does MAC filtering specifically achieve in a secured wireless network?

Restricts access based on unique hardware addresses Signup and view all the answers

Which aspect differentiates WPA2 from WPA in terms of security features?

WPA2 implements mandatory elements of IEEE 802.11i Signup and view all the answers

What does the SSID help a client device to accomplish in a wireless LAN?

Identify and select the correct access point to connect to Signup and view all the answers

What is the function of the BSSID in a wireless network?

To uniquely identify each Basic Service Set within a LAN Signup and view all the answers

When a mobile station transfers its association from one access point to another, which process is utilized?

Re-association Signup and view all the answers

Which statement best describes the privacy feature in the 802.11 standard?

It allows for optional encryption to keep messages confidential between intended recipients Signup and view all the answers

What characteristic differentiates a BSSID from an SSID in a wireless network?

BSSID uniquely identifies each BSS, whereas SSID is a shared name among multiple access points Signup and view all the answers

In terms of network management, why is the SSID significant?

It facilitates the broadcasting of a network name to users and devices Signup and view all the answers

What is an indication that a broadcast BSSID is being utilized?

The BSSID has a value that includes all 1s Signup and view all the answers

What is a key purpose of authentication in the context of the IEEE 802.11 standard?

To verify the identity of stations connecting to the network Signup and view all the answers

Study Notes

Wireless LAN

Wireless LANs (WLANs) are similar to traditional LANs, but with a wireless interface.
WLAN technology is becoming popular due to the introduction of small, portable devices like PDAs.
WLANs provide high-speed data communication in small areas like buildings or offices.
Users can move around a confined area while staying connected to the network.
Wi-Fi is a synonym for IEEE 802.11 technology and IP Radio.

Wi-Fi and Access Points

Wi-Fi-enabled devices (e.g., computers, video game consoles, mobile phones) can connect to the internet when within range of a wireless network.
Access points are nodes in WLANs that act as central transmitters and receivers of radio signals.
Home or small business access points are small, dedicated hardware devices usually containing a network adapter, antenna, and radio transmitter.
Access points support Wi-Fi wireless communication standards.

Wireless Application Protocol (WAP)

WAP defines a network architecture for content delivery over wireless networks.
WAP implements protocols similar to well-known web protocols like HTTP, TCP, and SSL.
WAP enables global wireless communication across different wireless technologies (e.g., GSM, GPRS, UMTS, 3G).

IEEE 802.11 Layered Protocol Architecture

Association: Establishes an initial connection between a station and an access point.
Re-Association: Allows transferring an existing association from one access point to another.
Dis-association: Notifies termination of an existing association.
Authentication: Establishes the identity of a station.
Privacy: Prevents message content from being read by unauthorized recipients using encryption.

Service Set Identifier (SSID)

A name that identifies a specific 802.11 wireless LAN.
Client devices can receive broadcast messages from access points advertising their SSIDs.
SSIDs can be up to 32 characters long.
Multiple access points can share the same SSID if they provide access to the same network.

Basic Service Set Identifier (BSSID)

Uniquely identifies each Basic Service Set (BSS) in an infrastructure BSS.
The BSSID is the MAC address of the wireless access point (WAP).
In an Independent Basic Service Set (IBSS), the BSSID is a locally generated 48-bit random number with the individual/group bit set to 0 and the universal/local bit set to 1.
A BSSID with a value of all 1s indicates a broadcast BSSID.

Transmission Technology

Microwave: Uses low-power microwave radio signals at the 18GHz frequency band.
Spread Spectrum: Uses frequency hopping and direct sequence modulation to transmit data. The signal spreads over a wider frequency range.
Infrared: Diffused, directed, or directed point-to-point transmissions using infrared light.

WLAN Architecture

WLAN stations (STAs) and Access Points (APs) are the building blocks.
WLAN Stations: Locate and connect to access points to access network resources.
Access Points: Connect WLAN stations to a wired network.
Basic Service Set (BSS): The minimum BSS consists of two stations.
Independent Basic Service Set (IBSS) / Ad hoc network: Network of client devices without a controlling access point.
Extended Service Set (ESS): Interconnected BSSs that appear as a single BSS to the logical link control layer.
Distribution System (DS): Connects access points in an extended service set to increase network coverage.

WLAN Applications and Standards

WLANs have applications from small home networks to large campus networks, to mobile networks on airplanes and trains.
Users can access the internet, connect to 3G/4G networks, and can use public access points.
IEEE 802.11 standards define WLAN protocols and frequencies. Specific standards and their bandwidths and performance are described.

Wireless LAN Security

Security is a major concern due to the open nature of wireless communication.
Administrators and users should take precautions to prevent unauthorized access.
Security measures include encryption protocols (WEP, WPA, WPA2).
MAC filtering.
Firewall configuration is required for advanced security.

Wi-MAX

Wi-MAX (Worldwide Interoperability for Microwave Access) is a long range wireless technology using a variety of transmission modes.
It provides wireless broadband access and telecommunications services.

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Description

Explore the fundamentals of Wireless Local Area Networks (WLANs) and Wi-Fi technology. This quiz covers the essentials of WLAN functionality, Wi-Fi devices, access points, and the Wireless Application Protocol. Understand how wireless communication has transformed networking in various environments.