Transcript 產品銷售建議案
Wireless LAN, WLAN Security, and VPN 麟瑞科技 台南辦事處 技術經理 張晃崚 WLAN & VPN FAQ • • • • • • • • • What is WLAN?802.11a?802.11b?802.11g? Which standard (product) should we use? How to deploy WLAN? How to block intruders? How to authenticate users? How to keep data secure? What is roaming? How to provide a fast path for some VIP users? How to exchange data securely between offices? Agenda • • • • • Introduction to Wireless LAN WLAN deployments WLAN security issues WLAN security solutions VPN solutions Agenda • • • • • Introduction to Wireless LAN WLAN deployments WLAN security issues WLAN security solutions VPN solutions What is Wireless Network • Wireless Network: – 802.11x standards (Wi-Fi) – Cell phones – Bluetooth – HomeRF – Fixed Broadband wireless, IEEE 802.16 – Mobile broadband – Optical point-to-point wireless What is Wireless LAN • IEEE 802.11-based networks • Bluetooth is regarded as a PAN (Personal Area Network) • Need Wireless NIC and Access Point(AP) Wireless LAN vs. Wired LAN Wireless LAN Media Access CSMA/CA Wired LAN CSMA/CD -10 Bit error rate 0.1% 10 Duplex half half/full Speed slow fast Throughput Reduce 50-60% N/A Wireless LAN vs. Wired LAN • All 802 WLANs employ handshaked transmission to compensate • WLAN just like PUSH-to-TALK radio • WLAN will be a step backward: slower speed, half duplex, shared media. • BUT, gain FREEDOM • AP usually is a Layer 2 bridge (between wired LAN and wireless LAN) • Spanning Tree Protocol issue Wireless LAN Standards 802.11b Frequency Channel Max speed 802.11a 802.11g 2.4 GHz 5 GHz 2.4 GHz 3 8 3 11Mbps 54Mbps 54Mbps Real throughput 4-6 Mbps Interference Yes No Yes Distance for max speed 120-140 ft. 1-2 ft. 120-140 ft. Distance for half speed 120-140 ft. 60 ft. ??? ft. Very mature Early No product Maturity 22-27 Mbps 22-27 Mbps 802.11b+ • IEEE 802.11g will be finalized in May 2003 • Not a formal IEEE specification • Texas Instruments (TI) applied PBCC to enable 22Mbps data rate • Interoperable with 802.11b device at 11Mbps • Must use TI’s chip to enable 22Mbps Other 802.11x standard • • • • 802.11d: Multiple regulatory domains 802.11e: QoS 802.11f: Inter-Access Point Protocol (IAPP) 802.11h: Dynamic Frequency Selection(DFS) and Transmit Power Control (TPC) • 802.11i: Security Which Technology should you use? • Decision should be based on requirements of system/users • User bandwidth requirements • User density • Overall implementation cost • Upgrade requirements • Client availability • Client platform features Agenda • • • • • Introduction to Wireless LAN WLAN deployments WLAN security issues WLAN security solutions VPN solutions Typical WLAN Topologies Wireless “Cell” Channel 1 Wireless “Cell” Channel 6 LAN Backbone Access Point Wireless Clients Access Point Wireless Clients Wireless Repeater Topology Wireless Repeater “Cell” Channel 1 LAN Backbone Channel 1 Access Point Wireless Clients Access Point Hot Standby LAN Backbone Monitored AP Standby AP Wireless Clients Multi-rate Implementations 2 Mbps 2 Mbps 2 Mbps 2 Mbps 2 Mbps 5.5 Mbps 5.5 Mbps 5.5 Mbps 5.5 Mbps 5.5 Mbps 11 Mbps 11 Mbps 11 Mbps 11 Mbps 11 Mbps 11 Mbps 11 Mbps 11 Mbps 11 Mbps 11 Mbps 5.5 Mbps 5.5 Mbps 5.5 Mbps 5.5 Mbps 5.5 Mbps 2 Mbps 2 Mbps 2 Mbps 2 Mbps 2 Mbps Vendor Offering • • • • • • • • • • • Higher and variable transmission power External antennas Little throughput degradation with encryption Line-power via the wired Ethernet cable Dual-band: 802.11b + 802.11a AP load balancing Roaming between IP subnets Hot Standby AP VLAN support Lockable case Enhanced security features: 802.1x, 802.11i draft, etc. Agenda • • • • • Introduction to Wireless LAN WLAN deployments WLAN security issues WLAN security solutions VPN solutions WLAN Security Issues • Wireless is like having an RJ45 jack in the parking lot • Need to deny access to intruders • Need to secure message with good encryption technology WLAN Security Issues • Managing the security side of you networks requires several things –Protecting the ‘network’ from intruders •Requires authentication for users –Protecting the Wireless DATA from sniffers •Requires some type of encryption –Protecting you RF networks from being detected –The ability to MANAGE you users credentials •Includes WEP keys, users names, passwords, etc. –Protecting your wireless infrastructure from improper configuration •Required a good user manager interface on APs WLAN Security Issues • Managing the security side of you networks requires several things –To dynamically assign user’s IP address, gateway, etc. •Deploy DHCP server –To let roaming users be authenticated by their original account and passwords •Requires authentication roaming features for authentication servers Agenda • • • • • Introduction to Wireless LAN WLAN deployments WLAN security issues WLAN security solutions VPN solutions Authentication Techniques • Open System Authentication • No security • SSID Authentication • SSID is broadcast in clear text form • Can be obtained by snooping on traffic • Shared key Authentication (WEP) • Key stolen • Employee leaves Authentication Techniques • MAC address Authentication • • • • MAC is sent in clear form Can be obtained be snooping Attackers may change their MAC to match Not flexible and scalable • 802.1x and Extensible Authentication Protocol (EAP) • Secure not only client but also devices • Only Windows XP and few vendors support this technique Authentication Techniques • VPN client Authentication • Does good authentication and encryption • Variable authentication and encryption method to choose • Need VPN client software installed • Wireless Gateway Authentication • No need to install any client software • Pop up authentication window when initiating connection (use web browser) • Easy to install and configure • One wireless gateway for a subnet Wireless Gateway Topology Blocking Inter-client communication • PSPF—Publicly Secure Packet Forwarding • Prevents WLAN interclient communication • Relies on MAC address • Same subnet devices only Encryption Techniques • Key Management • Can be painful • Requires a power tool to manage keys • Easy to hack with well-know single key • Key Rotation • Changing the user’s key periodically • • • • Broadcast Key Rotation WEP Encryption 128 bit WEP IPsec Encryption Techniques • IEEE 802.11i • TKIP (Data Integrity) • MIC (Data Integrity) • AES (Encryption) • Not yet complete WLAN Security Solution Product • Wireless Gateway • Bluesocket • Vernier • ReefEdge • VPN • Cisco VPN concentrator/router/client • NetScreen • Authentication Server • Cisco ACS (RADIUS, TACACS, LEAP) • RADIUS WLAN Security Solution Product Campus switch DHCP&AAA Server Wireless Gateway (Bluesocket) Or VPN Gateway (Cisco/NetScreen) Cisco Aironet 1100 (802.11b, 802.11g) Mobile IP VLAN Cisco Aironet 1200 (802.11a, 802.11b, 802.11g) External Antenna Cisco Aironet 1200 AP • Modular platform for single or dual band operation • Field upgradeable radios • Modular design enhances future upgrade ability • Simultaneous dual radio operation • 10/100 Ethernet LAN uplink Cisco Aironet 1100 AP •VLAN support •802.11b, 802.11g (2.4 GHz) Bluesocket Wireless Gateway Agenda • • • • • Introduction to Wireless LAN WLAN deployments WLAN security issues WLAN security solutions VPN solutions VPN Type and Applications Type Application Remote Access VPN Remote Dial Connectivity Site-to-Site Site-to-Site VPN Extranet VPN As Alternative To Dedicated Dial Benefits Ubiquitous Access Lower Cost ISDN Leased Line Internal Frame Relay Connectivity ATM Biz-to-Biz Fax External Mail Connectivity EDI Extend Connectivity Increased Bandwidth Lower Cost Facilitates E-Commerce VPN Type and Applications Extranet Business Partner Mobile User POP Internet DSL Cable Home Telecommuter VPN Central Site Site-to-Site Remote Office Remote Access VPN Cisco VPN Clients Microsoft Win 2000 (IPSec) Microsoft Win 9x/NT (PPTP) WAN Router PIX Firewall Cisco VPN 3000 Concentrator Cisco Secure ACS (AAA) Telecommuter Internet VPN POP Central Site Mobile Customer Site-to-Site VPN Remote Campus Main Campus Remotel Campus Internet Small Office/ Home Office Extranet VPN Supplier ISP Gateway Remote Office Firewall Security Server Supplier ISP Network DMZ Corporate Intranet