Free CWNP CWNA-109 Practice Exam with Questions & Answers | Set: 2

The IEEE 802.11ax standard, also known as High-Efficiency Wireless (HEW) or simply HE, includes support for operation across multiple frequency bands: 2.4 GHz, 5 GHz, and, with the appropriate regulatory approvals, the 6 GHz band. This makes option D the correct answer. Here's how it compares to the other options:

HE (802.11ax): Introduced as an enhancement over previous standards, 802.11ax is designed to improve efficiency, especially in dense environments. It supports operation in the 2.4 GHz, 5 GHz, and 6 GHz bands (the latter pending regulatory approval in various regions), making it highly versatile and future-proof.

VHT (802.11ac): Very High Throughput, or 802.11ac, operates exclusively in the 5 GHz band. It introduced significant speed improvements over its predecessor (802.11n) but does not support the 2.4 GHz or 6 GHz bands.

HT (802.11n): High Throughput, or 802.11n, supports operation in both the 2.4 GHz and 5 GHz bands. However, it does not include support for the 6 GHz band.

HR/DSSS (802.11b): High-Rate Direct Sequence Spread Spectrum, or 802.11b, operates only in the 2.4 GHz band. It was one of the early Wi-Fi standards and does not support 5 GHz or 6 GHz bands.

Given these distinctions, only 802.11ax (option D) supports operation across all three mentioned bands, aligning with the requirements stated in the question.

The WLAN feature that would allow the network administrator to control the network resources that can be accessed by each employee based on their department is Role-Based Access Control (RBAC). RBAC is a method of assigning different permissions and policies to users or groups based on their roles in the organization. RBAC can be implemented by using VLANs, ACLs, or firewalls to restrict access to certain network segments or resources. RBAC can also be integrated with 802.1X/EAP authentication to dynamically assign roles and VLANs to users based on their credentials. References: [CWNP Certified Wireless Network Administrator Official Study Guide: Exam CWNA-109], page 403; [Role-Based Access Control (RBAC) in Wireless Networks], page 1.

MU-MIMO capabilities of the bridges are not a factor considered when calculating the Link Budget for an outdoor point-to-point WLAN bridge link. The Link Budget is a calculation of the expected signal strength at the receiver based on various factors that affect the RF transmission. Some of these factors are operating frequency, transmit power, receive antenna gain, free space path loss, cable loss, connector loss, and environmental loss. MU-MIMO stands for Multi-User Multiple Input Multiple Output, which is a technology that allows multiple devices to communicate simultaneously using multiple spatial streams. MU-MIMO is not relevant for a point-to-point link, where there are only two devices involved. References: 1, Chapter 2, page 59; 2, Section 2.2

A POE device that requires 47 W of power should use the 802.3bt specification. This is because 802.3bt is the latest POE standard that supports up to 90 W of power delivery over four pairs of wires in an Ethernet cable. The previous POE standards, such as 802.3af and 802.3at, only support up to 15.4 W and 30 W of power delivery over two pairs of wires in an Ethernet cable, respectively. Therefore, they are not sufficient for powering a device that requires 47 W of power. The 802.11at specification does not exist; it is a typo or confusion with the 802.3at specification. References: CWNA-109 Study Guide, Chapter 8: Wireless LAN Access Points, page 2431

What prevents each station from using all the airtime when other client stations are actively communicating in the same BSS is CSMA/CA. CSMA/CA stands for Carrier Sense Multiple Access with Collision Avoidance and is a media access control method used by WLAN devices to share the wireless medium. CSMA/CA works by having each station sense the medium before transmitting a frame. If the medium is busy (i.e., another station is transmitting), the station defers its transmission until the medium is idle. If the medium is idle, the station waits for a random backoff period before transmitting. This way, CSMA/CA reduces the chances of collisions and ensures fair access to the medium for all stations. CSMA/CA also uses positive acknowledgements to confirm successful transmissions and retransmissions to recover from errors. CSMA/CD, DOS prevention, and OFDMA are not used by WLAN devices in a BSS. References: [CWNP Certified Wireless Network Administrator Official Study Guide: Exam CWNA-109], page 108; [CWNA: Certified Wireless Network Administrator Official Study Guide: Exam CWNA-109], page 98.

An advantage of using WPA3-Personal instead of WPA2-Personal as a security solution for 802.11 networks is that WPA3-Personal, also called WPA3-SAE, uses a stronger authentication exchange to better secure the network. WPA3-Personal uses Simultaneous Authentication of Equals (SAE) as the key exchange protocol, which provides stronger protection against offline dictionary attacks and password guessing than WPA2-Personal. SAE uses a Diffie-Hellman key exchange with elliptic curve cryptography (ECC) to establish a pairwise master key (PMK) between the AP and the client without revealing it to any eavesdropper. SAE also provides forward secrecy, which means that if one PMK is compromised, it does not affect the security of other PMKs. WPA2-Personal uses Pre-Shared Key (PSK) as the key exchange protocol, which is vulnerable to offline brute-force attacks if the passphrase is weak or leaked. Both WPA3-Personal and WPA2-Personal use AES for encryption, so there is no difference in that aspect. WPA3-Personal does not use a different encryption algorithm than WPA2-Personal, but rather a different key exchange protocol. References: [CWNP Certified Wireless Network Administrator Official Study Guide: Exam CWNA-109], page 307; [CWNA: Certified Wireless Network Administrator Official Study Guide: Exam CWNA-109], page 297.

Cellular/LTE/5G is the best method for implementing a network backhaul for communications across the Internet in a remote area that is affected by a natural disaster. This is because cellular/LTE/5G networks are wireless and do not depend on physical infrastructure that may be damaged or unavailable in such scenarios. Cellular/LTE/5G networks also offer high-speed data transmission and wide coverage area, which are essential for emergency response operations. 802.11 bridging to the response team headquarters is not feasible because it requires line-of-sight and has limited range. Turning up the output power of the WLAN at the response team headquarters is not effective because it may cause interference and does not guarantee reliable connectivity. Temporary wired DSL is not practical because it requires installing cables and equipment that may not be available or accessible in a remote area. References: CWNA-109 Study Guide, Chapter 7: Wireless LAN Topologies, page 2031

 What you should tell him is that due to 802.11 network operations and the dynamic rates used by devices on the network, the two radios will likely not exceed the 1 Gbps Ethernet link. This is because the actual throughput of an 802.11 network is much lower than the theoretical data rates due to factors such as overhead, contention, interference, retransmissions, and environmental conditions. Moreover, the data rates used by devices on the network vary depending on their distance, signal quality, capabilities, and configuration. Therefore, it is unlikely that both radios of the AP will simultaneously use the maximum data rates and saturate the 1 Gbps Ethernet link. Upgrading to a 10 Gbps Ethernet link or running a second 1 Gbps Ethernet link may be unnecessary and costly. Compressing all data before transmitting it onto the Ethernet link may introduce additional overhead and latency. References: [CWNP Certified Wireless Network Administrator Official Study Guide: Exam CWNA-109], page 227; [CWNA: Certified Wireless Network Administrator Official Study Guide: Exam CWNA-109], page 217.

An IEEE 802.11 amendment is a proposed change or addition to the existing 802.11 standard, which defines the specifications and protocols for wireless LANs. An amendment goes through several stages of development, such as draft, sponsor ballot, and final approval, before it is ratified by the IEEE Standards Association and becomes part of the standard. Until then, it has no official impact on the standard, although some vendors may release products based on draft amendments to gain a competitive edge or to influence the final outcome of the amendment . References: [CWNA-109 Study Guide], Chapter 1: Overview of Wireless Standards, Organizations, and Fundamentals, page 25; [CWNA-109 Study Guide], Chapter 1: Overview of Wireless Standards, Organizations, and Fundamentals, page 23; [IEEE website], IEEE-SA Standards Development Process.

 The data rate of a signal is the speed that the data bits in individual 802.11 data frames are sent, but it does not account for the actual amount of data that can be transmitted over time. The throughput of a connection is the flow of information over time, which is affected by various factors such as data encoding, modulation, encryption, airtime utilization, noise levels, interference, etc. Therefore, the throughput is always lower than the data rate. According to one of the web search results1, the actual throughput is normally 60-70 percent of the supported data rates. So, for a connection with a data rate of 150 Mbps, the expected throughput would be around 90-105 Mbps.