LAN Switching and Wireless: Ch7 - Basic Wireless Concepts and Configuration
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The document discusses wireless technologies, focusing on wireless local area networks (WLANs) and their functionalities compared to traditional Ethernet LANs. It covers topics such as RF and infrared communication methods, WLAN standards, security threats, and access protocols like WPA and WPA2. Additionally, it highlights troubleshooting techniques for common WLAN issues and the importance of proper configuration for security and performance.
LAN Switching and Wireless: Ch7 - Basic Wireless Concepts and Configuration
- 1. LAN Switching and Wireless
- 2. If you found any mistake’s’ on these slides or if you have any other questions or comments, please feel free to contact me at: abdu.elsaid@gmail.com or abdu.elsaid@yahoo.com Linkedin : https://www.linkedin.com/in/AbdelkhalikMosa Twitter : https://twitter.com/AbdelkhalikMosa Facebook : https://www.facebook.com/Abdelkhalik.Mosa Thanks, Abdelkhalik Mosa Suez Canal University Faculty of Computers and Informatics - Ismailia - Egypt Note …
- 3. Introduction • Wireless technologies use electromagnetic waves to carry information between devices. • WLANs use radio frequencies (RF) instead of cables at the Physical layer and MAC sub-layer of the Data Link layer.
- 4. Wireless LAN Vs. Ethernet LAN
- 5. Wireless PAN, LAN, MAN and WAN PAN : Personal Area Networks LAN : Local Area Networks WLAN : Wireless Local Area Networks MAN : Metropolitan Area Networks WAN : Wide Area Networks
- 6. Introduction: Infrared • Infrared (IR) is relatively low energy and cannot penetrate through walls or other obstacles. • A specialized communication port known as an Infrared Direct Access (IrDA) port uses IR to exchange information between devices. • IR only allows a one-to-one type of connection. • IR is also used for remote control devices, wireless mice, and wireless keyboards. • IR generally used for short-range, line-of-sight, communications.
- 7. Introduction: Radio Frequency (RF) • RF waves can penetrate through walls and other obstacles, allowing a much greater range than IR. • Certain areas of the RF bands have been set aside for use by unlicensed devices such as WLANs, and computer peripherals. – This includes the 900 MHz, 2.4 GHz, and the 5 GHz frequency ranges. These ranges are known as the ISM bands.
- 8. Benefits of Wireless Technology
- 9. Limitations of Wireless Technology
- 10. Wireless LANs (WLANs) • 802.11 wireless LANs extend the 802.3 Ethernet LAN infrastructures to provide additional connectivity options.
- 11. Wireless LAN Standards • The governmental agencies in countries, license some frequency bands, leaving some frequency bands unlicensed. • Licensed bands: – The most common are AM and FM radio, shortwave radio (for police department communications), and mobile phones. • Unlicensed frequencies: – Can be used by all kinds of devices; however, the devices must still conform to the rules set up by the regulatory agency. • A device using an unlicensed band must use power levels at or below a particular setting so as not to interfere too much with other devices sharing that unlicensed band.
- 12. Wireless LAN Standards • OFDM have faster data rates than DSSS. • DSSS is simpler and less expensive to implement than OFDM.
- 13. Wireless Fidelity (Wi-Fi) Certification • Wi-Fi Alliance, a global, nonprofit, industry trade association devoted to promoting the growth and acceptance of WLANs. • The Wi-Fi Alliance is an association of vendors whose objective is to improve the interoperability of products that are based on the 802.11 standard. • The Wi-Fi logo on a device means it meets standards and should interoperate with other devices of the same standard. • The three key organizations influencing WLAN standards are: ITU-R regulates allocation of RF bands. IEEE specifies how RF is modulated to carry info. Wi-Fi ensures that vendors make devices that are interoperable.
- 14. Wireless Infrastructure Components: Wireless NIC Wireless NIC encodes a data stream onto an RF signal.
- 15. Wireless Infrastructure Components: Wireless Access Points • An access point is a Layer 2 device that functions like a 802.3 Ethernet hub. • An access point connects wireless clients to the wired LAN. • Association is the process by which a client joins an 802.11 network. • RF signals attenuate as they move away from their point of origin, causing the Hidden node problem. • One means of resolving the hidden node problem is a CSMA/CA feature called request to send/clear to send (RTS/CTS).
- 16. Wireless Infrastructure Components: Wireless Access Points • The hidden node problem
- 17. Wireless Infrastructure Components: Wireless Routers • Wireless routers perform the role of access point, Ethernet switch, and router.
- 18. Configurable Parameters for Wireless Endpoints Network Modes Channels SSID
- 19. 802.11 Topologies: Ad Hoc (IBSS) Independent Basic Service Set (IBSS)
- 20. 802.11 Topologies: BSS Basic Service Set (BSS)
- 21. 802.11 Topologies: ESS Extended Basic Service Set (ESS)
- 22. Client and Access Point Association: Beacons • Beacons: Frames used by the WLAN network to advertise its presence.
- 23. Client and Access Point Association: Probes • Probes: Frames used by WLAN clients to find their networks.
- 24. Client and Access Point Association: Authentication
- 25. Client and Access Point Association: Association • Association: The process for establishing the data link between an access point and a WLAN client.
- 26. Threats to Wireless Security: Unauthorized Access • Major categories of threats that lead to unauthorized access: 1. War Drivers: • Find open networks and use them to gain free internet access. 2. Hackers: • Exploit weak privacy measures to view sensitive WLAN information and even break into WLANs. 3. Employees: • Plug consumer-grade APIs/gateways into company Ethernet ports to create their own WLANs.
- 27. Threats to Wireless Security: Man-in-the-Middle Attacks
- 28. Threats to Wireless Security: Denial of Service
- 29. Wireless Security Protocol Overview • Open Authentication: no authentication. • WEP authentication: was supposed to provide privacy to a link. Static, crackable, and not scalable. Cloaking SSIDs and filtering MAC addresses were used.
- 30. Authenticating to the Wireless LAN
- 31. Authenticating to the Wireless LAN • EAP is a framework for authenticating network access.
- 32. Encryption – TKIP and AES • TKIP is the encryption method certified as WPA. It encrypts the Layer 2 payload. It carries out a message integrity check (MIC) in the encrypted packet which ensures against a message being tampered with. • AES is the encryption method certified as WPA2. • PSK or PSK2 with TKIP is the same as WPA. • PSK or PSK2 with AES is the same as WPA2. • PSK2, without an encryption method, is the same as WPA2.
- 33. Controlling Access to the Wireless LAN • The concept of depth means having multiple solutions available. • Implement this three-step approach: 1. SSID cloaking: Disable SSID broadcasts from access points 2. MAC address filtering: Permit or deny clients based on their MAC address 3. WLAN security implementation: WPA or WPA2. • Neither SSID cloaking nor MAC address filtering are considered a valid means of securing a WLAN for the following reasons: 1. MAC addresses are easily spoofed. 2. SSIDs are easily discovered even they aren’t broadcasted.
- 34. Configuring the Wireless Access PointSetup
- 35. Configuring the Wireless Access Point Management
- 36. Configuring Basic Wireless Settings NetworkMode
- 37. Configuring Basic Wireless Settings NetworkName(SSID)
- 38. Configuring Basic Wireless Settings RadioBand
- 39. Configuring Basic Wireless Settings WideChannel
- 40. Configuring Basic Wireless Settings StandardChannel
- 41. Configuring Security • "Personal“ means no AAA server is used. • "Enterprise“ means a AAA server and EAP authentication is used.
- 43. Configuring a wireless NIC Scan for SSIDs Selecting the Wireless Security Protocol
- 44. WLAN Troubleshooting: Incorrect Channel Settings
- 45. WLAN Troubleshooting: Incorrect Channel Settings
- 46. WLAN Troubleshooting: Incorrect Channel Settings
- 47. WLAN Troubleshooting: Solving RF Interference
- 48. WLAN Troubleshooting: Solving RF Interference
- 49. WLAN Troubleshooting: Solving RF Interference
- 50. WLAN Troubleshooting: Access Point Misplacement
- 51. WLAN Troubleshooting: Access Point Misplacement
- 52. WLAN Troubleshooting: Access Point Misplacement
- 53. WLAN Troubleshooting: Authentication and Encryption
- 54. WLAN Troubleshooting: Authentication and Encryption
- 55. WLAN Troubleshooting: Authentication and Encryption