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WIRELESS NETWORK SECURITY

WIRELESS NETWORK SECURITY. Objective. Understand basic wireless technology Understand the components of wireless network and implement a wireless network Build a wireless LAN Understand the security issues of wireless network

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WIRELESS NETWORK SECURITY

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  1. WIRELESS NETWORK SECURITY Part 1

  2. Objective • Understand basic wireless technology • Understand the components of wireless network and implement a wireless network • Build a wireless LAN • Understand the security issues of wireless network • Look at various protection methods and explore how to apply some of these protections to a school environment Part 1

  3. Contents • Brief introduction to networking • WAN, MAN, LAN, • Fundamental Wireless Technologies • Wireless LAN, Bluetooth • Comparison of technologies and issues • Look at Wireless LAN component • Wireless clients • AP • Build different types of wireless networks • Ad-hoc and infrastructure networks Part 1

  4. What is a Network? …..is a group of two or more personal computers or devices linked together with a media…. Part 1

  5. Local Area Network (LAN) • Typically connects computer in a single building or campus. • Medium : optical fibers, coaxial cables, twisted pair, wireless (WiFi). • High speed networks (100 Mbps/10 Gbps Ethernet) • Cheaper equipments, Ethernet, Token Ring • Setup Client and Server or Peer to Peer Part 1

  6. Wide Area Network (WAN) • Generally covers large distances (states, countries, continents). • Typical Medium : Land and Ocean cables • Wireless Medium - satallites. • Problems with delays if using satellites. • Typical speed : 20 - 2000 Kbits/s. - expensive • New standards (ATM) are changing the landscape. LAN vs WAN speed Part 1

  7. Metropolitan Area Network (MAN) • Generally covers towns and cities (50 kms) • Typical medium : optical fibres, cables • Message routing is fast. • Mobile technology – 2G, 3G and 4G Part 1

  8. What is Wireless Technology? • Refers to Hardware and Software that allow information be transmitted between devices • Devices • Equipment that can send and received • Network • h/w & s/w used to link and transmit information over a media • Applications • S/w that operate the wireless device Part 1

  9. Why Wireless • Mobility (Roaming) • Easy of Installation • Scalability (WiFi) • Cost Part 1

  10. Why Wireless Now? • Information access when needed, anywhere • Emergence of powerful handheld devices • Improved network data exchange • Maturing device, network and data exchange standards Part 1

  11. Some Wireless Technology? To most people/organsiations wireless technology means: 3G WiMax Blue tooth Wireless LAN GPRS Wireless technology refers to hardware and software that allows information to be transmitted between devices without using physical wired connections. Part 1

  12. Wireless LAN Competing Technologies 802.11 competes with HiperLAN Part 1

  13. Personal Area Network (PAN) • Operate in the gigahertz frequency spectrum but differ from other wireless technologies in the range of service, network capacity and data bit transfer rate. • Designed to operate over a much smaller service area. • Devices that participate in these types of peer based networks are designed to automatically discover other devices and services. • Connects personal computers to mobile devices including PDAs, phones, personal printers and other handheld devices. Part 1

  14. Bluetooth • Originated from an Ericsson internal project • To facilitate voice and data access • Operate at 2.4 – 2.483 MHz ISM band • Short range (10 meter) frequency-hopping radio link between devices • Data can be delivered up to 724 kbps Part 1

  15. Bluetooth Standards (1) • Bluetooth 1.0 and 1.0B • Bluetooth 1.1 • Fixed problems with V1 and support for non encrypted channels • Bluetooth 1.2 • Better audio (Stereo sound, A2DP) • Bluetooth 2.0 • EDR (3Mbps) • Bluetooth 2.1 • Better power consumption • Better Pairing Part 1

  16. Radio Spectrum Gamma Ray Emitted by nuclear reaction 1021 Hz X-Ray Penetrating live tissues 1018 Hz Ultraviolet 1015 Hz Infrared Remote control, optical network T-Ray 1012 Hz Microwave Used for heating, communication, and radar 109 Hz 106 Hz Radio Used for communication 103 Hz Part 1

  17. Mobile Phones Technology The most used wireless technology is the mobile phone Mobile phones became popular in the 1980s and 1990s. Now in Hong Kong over 91% of the population owns a mobile phone. Various operators offer different services but they can be grouped into two types: Mobile phones provide two major functions: Voice – GSM, CDMA, TDMA Data - GRPS, WAP * SMS, EMS, MMS * Internet Access * Email * Value Added features Part 1

  18. Transmission and Cells Cell using directional transceiver Cell using omnidirectional transceiver Idealised hexagonal network Overlapping circular cells Microcell within network Part 1

  19. Mobile Phone Development Since the development of mobile phones have seen a number of generations • 1st Generation • This the analog phones dominated by two main standards, Analog Mobile Phone System (AMPS) and Total Access Communication System (TACS) • 2nd Generation • Digital phones with better sound quality • CDMA, TDMA, GSM and PCS became common terms • Basic data transmission, modem, fax at 9.6kbps • 2.5 Generation • Faster data transmission with GPRS, for SMS, MMS at 14.4k – 115kbps • Enhanced Data for GSM Evolution (EDGE)allowed 384Kbps • 3rd Generation • WCDMA, CDMA2000 - Video streaming, high-speed Internet • Development even faster data access at 2Mbps for Internet applications Part 1

  20. WIRELESS LAN TECHNOLOGIES Part 1

  21. Wireless LAN Technology The most popular WLAN technology today is based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11x standard. Draft 2 (expect to rectify late 2009) plus error correction code Part 1

  22. Original 802.11 • Proposed by IEEE 802.11 working group • Started in May 1991 and completed in 1997 • Transmission rate 1Mbps and 2Mbps • 3 data transmission adopted • Frequency Hop Spread Spectrum (FHSS- 1Mbps) • Direct Sequence Spread Spectrum (DSSS- 2Mbps) • Infrared (IrDA – Infrared Data Association) Part 1

  23. 802.11b • Added in Dec. 1999 • Operating at 2.4GHz range • Support speed 11, 5.5, 2 & 1Mbps • Using Higher Rate - Direct-Sequence Spread Spectrum (HR-DSSS) • Employs the Complementary Code Keying (CCK) modulation technique • Newly added 22Mbps (802.11b+) Not official Part 1

  24. 802.11a • Added in Dec. 1999 • Operating at 5 GHz range • Support speed 6, 9, 12, 18, 24, 36, 48 & 54Mbps • Using Orthogonal Frequency Division Multiplexing (OFDM) Part 1

  25. 802.11g • Added 2003 (Ratified in June) • Operating at 2.4 GHz range • Support speed between 24 and 54Mbps • Using Orthogonal Frequency Division Multiplexing (OFDM) - Mandatory • Also support Complimentary Code Keying (CCK) – Optional (backward compatibles with 802.11b) Part 1

  26. IEEE 802.11 Specification Part 1

  27. Radio Frequency for Wireless LAN Hong Kong Allocation USA Allocation ISM = Industrial, Scientific and Medical Part 1

  28. Hong Kong Allocation for 802.11b Part 1

  29. Hong Kong Allocation for 802.11a Part 1

  30. 802.11b Channels Wireless 802.11b networks operate in UHF band, specifically between 2.4GHz and 2.5GHz. These frequency is divided into 14 channels. US & Canada channel 1- 11 is available, Europe use 1 – 13, France uses 10-13 and Japan 1-14. Part 1

  31. Channel used for sending data Data is not transmitted in a single frequency, it is spread over multiple frequencies From the rule set only channel 1 , 6 and 11 do not overlap. But channel 5, 6 , and 7 affects all rule sets (Ideal for Jammers) Part 1

  32. Channel Allocations for 802.11b Each DS (Direct Sequence) Channel is transmitted over 22 Mhz Channel Centers are separated by 5 Mhz Part 1

  33. 20 Mhz 20 Mhz 5200 5220 5240 5260 5280 5300 5320 5350 5150 5180 Channel Allocations for 802.11a Each channel is 20Mhz Part 1

  34. Wireless LAN setup Demo Wire LAN • Connect to AP • Configure to AP • Test connection to Internet Part 1

  35. Speed vs Distance (2.4 Ghz) Part 1

  36. Speed vs Distance (5 Ghz) 802.11a+ ? Part 1

  37. What affects Range of Transmission Part 1

  38. 802.11n • Newest Wireless LAN standard • Final retification expected to be at late 2009 • Currently is Draft version 2 • Backward compatible to 802.11a/b/g Part 1

  39. 802.11n New Feature • MIMO (Multiple Input - Multiple Output) • defines many "M x N" antenna configurations, ranging from "1 x 1" to "4 x 4". This refers to the number of transmit (M) and receive (N) antennas – for example, an AP with two transmit and three receive antennas is a "2 x 3" MIMO device. • Better dealing with multipath signal reflections and attenuation • Channel Bonding • bonding to combine two adjacent 20 MHz channels into a single 40 MHz channel (most effective at 5GHz) • increases that throughput to 150 Mbps per channel • Aggregating of Frame • Transmit more than one application in single frame with fix header Part 1

  40. Wireless LAN Components Part 1

  41. Wireless LAN Components • Wireless client a computing device that is equipped with a wireless LAN network adapter. Wireless clients can communicate directly with each other or through a wireless access point. • Wireless Access Point a networking device equipped with a wireless LAN network adapter that acts as a bridge between wireless client and a traditional wired network Part 1

  42. Various Wireless Adapters for client PCMCIA USB Internal PCMCIA Adapter Internal Wireless Interface Part 1

  43. Basic Service Set The basic building block of an 802.11 network is the Basic Service set (BSS), which is simply a group of stations that communicate with each other Ad-hoc BSS Infrastructure BSS Part 1

  44. Extended Service Set Extended Service Set is for large networks Extended BSS AP (Bridge mode setting) Internet Part 1

  45. Workshop – Build simple wireless LAN (Ad-Hoc) Wire LAN • Ist client create a SSID(making it visible) and create a share folder with a file for other clients to download • Other Clients join this network • Test connection by download a file from 1st client Part 1

  46. Need wireless network adapter Define an SSID (Service Set IDentification) for “Adhoc” network All client connects to this SSID Building A Simple wireless network Install driver of Wireless Network Adapter Client 1 – set up a wireless group with SSID ADHOCxx – xx = 01 – 10 Client 2 – Connect to the ad-hoc network Part 1

  47. What is an Access Point? • At least 2 interface • Wireless Interface (802.11x) • Wired Interface (Ethernet or WAN port) • Bridge table • Dynamic Host Configuration Protocol (DHCP) • Network Address Translation (NAT) • Security filtering and Monitoring Access Point is a mean connecting wireless world and the wired world Some feature provided by AP Part 1

  48. 2 types of APs 1 - Residential Gateways/Routers • Target at price-conscious users • Simple connectivity • Limited functions 2 – Enterprise Gateways (AP) • More expensive • Large network connectivity and multi APs • More sophisticated functions • Device management • Greater Security functions Part 1

  49. Residential Gateways / Routers • Suitable for home or small office use • Deploy with one routable IP address, so NAT is implemented • Aim for connecting to a WAN via modem • May support VPN pass-through • IPSec • PPTP Example: Linksys WRT610N SMC WGBR14S-N Dlink DIR655 Part 1

  50. Home / small office setup ADSL/Cable Modem Internet Perform NAT Internal  Real IP address Wireless Router Internal Addresses Wireless NIC Part 1

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