CISSP All-in-One Exam Guide Chapter Review - PDF

CISSP All-in-One Exam Guide 590 Chapter Review Wireless networking is ubiquitous and, over the years, the security community has made great strides to ensure the confidentiality, integrity, and availability of our systems using these technologi...

CISSP All-in-One Exam Guide 590 Chapter Review Wireless networking is ubiquitous and, over the years, the security community has made great strides to ensure the confidentiality, integrity, and availability of our systems using these technologies. Still, risk can never be driven to zero, and this is particularly true when you transmit into free space, whether you do so using radio or light waves. Best practices for securing wireless networks include using strong cryptography, controlling access, and periodically testing the effectiveness of our controls. As security professionals, we must always be aware of the myriad of new wireless technologies being developed and sold. For each, we have to compare the benefits (which are always touted by the vendors) to the risks (which may be less obvious and more difficult to identify). The market will constantly push products that promise new features and functionality, even if they come at the cost of security. To be clear, most new technologies incorporate at least some basic security features (and in many cases, advanced security features too), but these are not always implemented in a systematic manner by their adopters. That’s where security professionals need to weigh in. Quick Review Wireless communication systems modulate data onto electromagnetic signals like radio and light waves. Normally, a higher frequency can carry more data, but over a shorter distance and with more susceptibility to interference. Wireless communication systems typically use carrier sense multiple access with collision avoidance (CSMA/CA) as a medium access control (MAC) protocol. A radio frequency band is a subset of the radio spectrum designated for a specific use. Wi-Fi systems operate in the 2.4-GHz and 5-GHz bands. Most wireless communication systems use one of two modulation techniques: spread spectrum or orthogonal frequency division multiplexing (OFDM). Spread spectrum modulation techniques include frequency hopping spread spectrum (FHSS) and direct sequence spread spectrum (DSSS). DSSS spreads the data being transmitted over a wider spectrum than would otherwise be needed in order to overcome interference and relies on a chip sequence to let receiving stations know how to reconstruct the transmitted data. FHSS uses a single subchannel at a time, but rapidly changes channels in a particular hop sequence. Wireless local area networks (WLANs) come in two forms: infrastructure and ad hoc. Environments can be segmented into different WLANs by using different SSIDs. 802.11a provides up to 54 Mbps and operates in the 5-GHz band.  Chapter 12: Wireless Networking 591 802.11b provides a transfer rate of up to 11 Mbps and works in the 2.4-GHz frequency range. 802.11g operates in the 2.4-GHz band and supports data rates of up to 54 Mbps. 802.11n, also known as Wi-Fi 4, supports throughputs of up to 100 Mbps and works in the 5-GHz band. IEEE 802.11ac (Wi-Fi 5) is an extension of 802.11n that increases throughput to 1.3 Gbps and is backward compatible with 802.11a, 802.11b, 802.11g, and 802.11n. The 802.11ax standard aims to address efficiency rather than faster speeds. Li-Fi is a wireless networking technology that uses light rather than radio waves to transmit and receive data. 802.16 is a metropolitan area network (MAN) wireless standard that allows wireless traffic to cover large geographical areas where stations can be as far as 70 km apart, using the 2.4-GHz and 5-GHz bands. The 802.15.4 standard defines the physical layer and Media Access Control sublayer of wireless personal area networks (WPANs). ZigBee is a standard for layers 3 (network) and 7 (application) that is built on PART IV top of 802.15.4 and is most commonly used in Internet of Things (IoT) and Industrial IoT systems. Bluetooth is another standard for WPANs, which is most commonly used to replace the cables connecting peripherals to computers and mobile devices. The 802.11e standard provides Quality of Service (QoS) and support of multimedia traffic in wireless transmissions. 802.11f standardizes the processes by which access points transfer active connections among themselves, enabling users to roam across APs. The 802.11h standard was developed to address interference issues in the 5-GHz band, particularly with regard to radar and satellite systems, through Dynamic Frequency Selection (DFS) and Transmit Power Control (TPC) techniques. 802.11j is an example of standards that allow common technologies such as WLANs to be employed in countries (in this case Japan) where local regulations conflict with portions of a broader standard (in this case 802.11). 802.11 was the original WLAN standard, which included Wired Equivalent Privacy (WEP); it is now obsolete. 802.11i defines Wi-Fi Protected Access 2 (WPA2) and is the most common standard in use in WLANs today. The IEEE 802.11w standard provides Management Frame Protection (MFP) that prevents certain types of attacks, such as replay and DoS attacks. WPA3 was developed by the Wi-Fi alliance (not IEEE) and is quickly replacing WPA2 for both personal and enterprise use.