LAN Hardware: Wireless Hardware PDF

LAN HARDWARE: 2.2 Wireless Hardware LAN TECHNOLOGIES SBA, 12/2024 12.1 Introduction to Wireless SBA, 12/2024 Introduction to Wireless Benefits of Wireless A Wireless LAN (WLAN) is a type of wireless network that is commonly used in homes,...

LAN HARDWARE: 2.2 Wireless Hardware LAN TECHNOLOGIES SBA, 12/2024 12.1 Introduction to Wireless SBA, 12/2024 Introduction to Wireless Benefits of Wireless A Wireless LAN (WLAN) is a type of wireless network that is commonly used in homes, offices, and campus environments. WLANs make mobility possible within the home and business environments. Wireless infrastructures adapt to rapidly changing needs and technologies. Introduction to Wireless Types of Wireless Networks Wireless Personal-Area Network (WPAN) – Low power and short-range (20-30ft or 6-9 meters). Based on IEEE 802.15 standard and 2.4 GHz frequency. Bluetooth and Zigbee are WPAN examples. Wireless LAN (WLAN) – Medium sized networks up to about 300 feet. Based on IEEE 802.11 standard and 2.4 or 5.0 GHz frequency. Wireless MAN (WMAN) – Large geographic area such as city or district. Uses specific licensed frequencies. Wireless WAN (WWAN) – Extensive geographic area for national or global communication. Uses specific licensed frequencies. Introduction to Wireless Wireless Technologies Bluetooth – IEEE WPAN standard used for device pairing at up to 300ft (100m) distance. Bluetooth Low Energy (BLE) – Supports mesh topology to large scale network devices. Bluetooth Basic Rate/Enhanced Rate (BR/EDR) – Supports point-to-point topologies and is optimized for audio streaming. WiMAX (Worldwide Interoperability for Microwave Access) – Alternative broadband wired internet connections. IEEE 802.16 WLAN standard for up 30 miles (50 km). Introduction to Wireless Wireless Technologies (Cont.) Cellular Broadband – Carry both voice and data. Used by phones, automobiles, tablets, and laptops. Global System of Mobile (GSM) – Internationally recognized Code Division Multiple Access (CDMA) – Primarily used on the US. Satellite Broadband – Uses directional satellite dish aligned with satellite in geostationary orbit. Needs clear line of site. Typically used in rural locations where cable and DSL are unavailable. Introduction to Wireless 802.11 Standards 802.11 WLAN standards define how radio frequencies are used for wireless links. IEEE Standard Radio Frequency Description 802.11 2.4 GHz Data rates up to 2 Mb/s 802.11a 5 GHz Data rates up to 54 Mb/s Not interoperable with 802.11b or 802.11g 802.11b 2.4 GHz Data rates up to 11 Mb/s Longer range than 802.11a and better able to penetrate building structures 802.11g 2.4 GHz Data rates up to 54 Mb/s Backward compatible with 802.11b 802.11n 2.4 and 5 GHz Data rates 150 – 600 Mb/s Require multiple antennas with MIMO technology 802.11ac 5 GHz Data rates 450 Mb/s – 1.3 Gb/s Supports up to eight antennas 802.11ax 2.4 and 5 GHz High-Efficiency Wireless (HEW) Capable of using 1 GHz and 7 GHz frequencies Introduction to Wireless Radio Frequencies All wireless devices operate in the range of the electromagnetic spectrum. WLAN networks operate in the 2.4 and 5 GHz frequency bands. ◦ 2.4 GHz (UHF) – 802.11b/g/n/ax ◦ 5 GHz (SHF) – 802.11a/n/ac/ax Introduction to Wireless Wireless Standards Organizations Standards ensure interoperability between devices that are made by different manufacturers. Internationally, the three organizations influencing WLAN standards: ◦ International Telecommunication Union (ITU) – Regulates the allocation of radio spectrum and satellite orbits. ◦ Institute of Electrical and Electronics Engineers (IEEE) – Specifies how a radio frequency is modulated to carry information. Maintains the standards for local and metropolitan area networks (MAN) with the IEEE 802 LAN/MAN family of standards. ◦ Wi-Fi Alliance – Promotes the growth and acceptance of WLANs. It is an association of vendors whose objective is to improve the interoperability of products that are based on the 802.11 standard 12.2 WLAN Components SBA, 12/2024 WLAN Components WLAN Components Antennas Wireless Router Internet Port Wireless Access Point Autonomous and controller-based access points WLAN Components Wireless NICs To communicate wirelessly, laptops, tablets, smart phones, and even the latest automobiles include integrated wireless NICs that incorporate a radio transmitter/receiver. If a device does not have an integrated wireless NIC, then a USB wireless adapter can be used. WLAN Components Wireless Home Router A home user typically interconnects wireless devices using a small, wireless router. Wireless routers serve as the following: ◦Access point – To provide wires access ◦Switch – To interconnect wired devices ◦Router - To provide a default gateway to other networks and the Internet WLAN Components Wireless Access Point Wireless clients use their wireless NIC to discover nearby access points (APs). Clients then attempt to associate and authenticate with an AP. After being authenticated, wireless users have access to network resources. Cisco Meraki Go access points WLAN Components AP Categories APs can be categorized as either autonomous APs or controller-based APs. Autonomous APs – Standalone devices configured through a command line interface or GUI. Each autonomous AP acts independently of the others and is configured and managed manually by an administrator. Controller-based APs – Also known as lightweight APs (LAPs). Use Lightweight Access Point Protocol (LWAPP) to communicate with a LWAN controller (WLC). Each LAP is automatically configured and managed by the WLC. WLAN Components Wireless Antennas Types of external antennas: Omnidirectional – Provide 360-degree coverage. Ideal in houses and office areas. Directional – Focus the radio signal in a specific direction. Examples are the Yagi and parabolic dish. Multiple Input Multiple Output (MIMO) – Uses multiple antennas (Up to eight) to increase bandwidth. 12.3 WLAN Operation SBA, 12/2024 WLAN Operation Wireless Client and AP Association For wireless devices to communicate over a network, they must first associate with an AP or wireless router. Wireless devices complete the following three stage process: ◦ Discover a wireless AP ◦ Authenticate with the AP ◦ Associate with the AP WLAN Operation Wireless Client and AP Association (Cont.) To achieve successful association, a wireless client and an AP must agree on specific parameters: ◦ SSID – The client needs to know the name of the network to connect. ◦ Password – This is required for the client to authenticate to the AP. ◦ Network mode – The 802.11 standard in use. ◦ Security mode – The security parameter settings, i.e. WEP, WPA, or WPA2. ◦ Channel settings – The frequency bands in use. 12.5 Channel Management SBA, 12/2024 Channel Management Channel Selection The 2.4 GHz band is subdivided into multiple channels each allotted 22 MHz bandwidth and separated from the next channel by 5 MHz. A best practice for 802.11b/g/n WLANs requiring multiple APs is to use non-overlapping channels such as 1, 6, and 11. Channel Management Channel Selection (Cont.) For the 5GHz standards 802.11a/n/ac, there are 24 channels. Each channel is separated from the next channel by 20 MHz. Non-overlapping channels are 36, 48, and 60.  12.7 Secure WLANs SBA, 12/2024 Secure WLANs SSID Cloaking and MAC Address Filtering To address the threats of keeping wireless intruders out and protecting data, two early security features were used and are still available on most routers and APs: SSID Cloaking APs and some wireless routers allow the SSID beacon frame to be disabled. Wireless clients must be manually configured with the SSID to connect to the network. MAC Address Filtering An administrator can manually permit or deny clients wireless access based on their physical MAC hardware address. In the figure, the router is configured to permit two MAC addresses. Devices with different MAC addresses will not be able to join the 2.4GHz WLAN. Secure WLANs 802.11 Original Authentication Methods The best way to secure a wireless network is to use authentication and encryption systems. Two types of authentication were introduced with the original 802.11 standard: Open system authentication No password required. Typically used to provide free internet access in public areas like cafes, airports, and hotels. Client is responsible for providing security such as through a VPN. Shared key authentication Provides mechanisms, such as WEP, WPA, WPA2, and WPA3 to authenticate and encrypt data between a wireless client and AP. However, the password must be pre-shared between both parties to connect. Secure WLANs Shared Key Authentication Methods There are currently four shared key authentication techniques available, as shown in the table. Authentication Method Description Wired Equivalent Privacy The original 802.11 specification designed to secure the data using the (WEP) Rivest Cipher 4 (RC4) encryption method with a static key. WEP is no longer recommended and should never be used. Wi-Fi Protected Access A Wi-Fi Alliance standard that uses WEP but secures the data with the (WPA) much stronger Temporal Key Integrity Protocol (TKIP) encryption algorithm. TKIP changes the key for each packet, making it much more difficult to hack. WPA2 It uses the Advanced Encryption Standard (AES) for encryption. AES is currently considered the strongest encryption protocol. WPA3 This is the next generation of Wi-Fi security. All WPA3-enabled devices use the latest security methods, disallow outdated legacy protocols, and require the use of Protected Management Frames (PMF). Secure WLANs WPA 3 Because WPA2 is no longer considered secure, WPA3 is recommended when available. WPA3 Includes four features: WPA3 – Personal : Thwarts brute force attacks by using Simultaneous Authentication of Equals (SAE). WPA3 – Enterprise : Uses 802.1X/EAP authentication. However, it requires the use of a 192-bit cryptographic suite and eliminates the mixing of security protocols for previous 802.11 standards. Open Networks : Does not use any authentication. However, uses Opportunistic Wireless Encryption (OWE) to encrypt all wireless traffic. IoT Onboarding : Uses Device Provisioning Protocol (DPP) to quickly onboard IoT devices.