ZyWALL 70 User’s Guide
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Chapter 6 Wireless LAN
6.7 Introduction to WPA
Wi-Fi Protected Access (WPA) is a subset of the IEEE 802.11i security specification draft.
Key differences between WPA and WEP are user authentication and improved data
encryption.
6.7.1 User Authentication
WPA applies IEEE 802.1x and Extensible Authentication Protocol (EAP) to authenticate
wireless clients using an external RADIUS database. You can't use the ZyWALL's Local User
Database for WPA authentication purposes since the Local User Database uses EAP-MD5
which cannot be used to generate keys. See later in this chapter and the appendices for more
information on IEEE 802.1x, RADIUS and EAP.
Therefore, if you don't have an external RADIUS server you should use WPA-PSK (WPA -
Pre-Shared Key) that only requires a single (identical) password entered into each access
point, wireless gateway and wireless client. As long as the passwords match, a client will be
granted access to a WLAN.
6.7.2 Encryption
WPA improves data encryption by using Temporal Key Integrity Protocol (TKIP), Message
Integrity Check (MIC) and IEEE 802.1x.
Temporal Key Integrity Protocol (TKIP) uses 128-bit keys that are dynamically generated and
distributed by the authentication server. It includes a per-packet key mixing function, a
Message Integrity Check (MIC) named Michael, an extended initialization vector (IV) with
sequencing rules, and a re-keying mechanism.
TKIP regularly changes and rotates the encryption keys so that the same encryption key is
never used twice. The RADIUS server distributes a Pairwise Master Key (PMK) key to the AP
that then sets up a key hierarchy and management system, using the pair-wise key to
dynamically generate unique data encryption keys to encrypt every data packet that is
wirelessly communicated between the AP and the wireless clients. This all happens in the
background automatically.
The Message Integrity Check (MIC) is designed to prevent an attacker from capturing data
packets, altering them and resending them. The MIC provides a strong mathematical function
in which the receiver and the transmitter each compute and then compare the MIC. If they do
not match, it is assumed that the data has been tampered with and the packet is dropped.
By generating unique data encryption keys for every data packet and by creating an integrity
checking mechanism (MIC), TKIP makes it much more difficult to decode data on a Wi-Fi
network than WEP, making it difficult for an intruder to break into the network.
Содержание ZyWALL 70
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Страница 38: ...ZyWALL 70 User s Guide 38 List of Figures ...
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Страница 74: ...ZyWALL 70 User s Guide 74 Chapter 2 Introducing the Web Configurator ...
Страница 92: ...ZyWALL 70 User s Guide 92 Chapter 3 Wizard Setup ...
Страница 102: ...ZyWALL 70 User s Guide 102 Chapter 4 LAN Screens ...
Страница 108: ...ZyWALL 70 User s Guide 108 Chapter 5 Bridge Screens ...
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Страница 136: ...ZyWALL 70 User s Guide 136 Chapter 7 WAN Screens Figure 45 WAN General ...
Страница 155: ...ZyWALL 70 User s Guide Chapter 7 WAN Screens 155 Figure 55 Dial Backup Setup ...
Страница 188: ...ZyWALL 70 User s Guide 188 Chapter 10 Firewall Screens Figure 71 Creating Editing A Firewall Rule ...
Страница 193: ...ZyWALL 70 User s Guide Chapter 10 Firewall Screens 193 Figure 76 My Service Rule Configuration ...
Страница 234: ...ZyWALL 70 User s Guide 234 Chapter 13 Introduction to IPSec ...
Страница 246: ...ZyWALL 70 User s Guide 246 Chapter 14 VPN Screens Figure 112 VPN Rules IKE Gateway Policy Edit ...
Страница 252: ...ZyWALL 70 User s Guide 252 Chapter 14 VPN Screens Figure 113 VPN Rules IKE Network Policy Edit ...
Страница 275: ...ZyWALL 70 User s Guide Chapter 15 Certificates 275 Figure 125 My Certificate Details ...
Страница 294: ...ZyWALL 70 User s Guide 294 Chapter 16 Authentication Server Figure 136 Local User Database ...
Страница 314: ...ZyWALL 70 User s Guide 314 Chapter 17 Network Address Translation NAT ...
Страница 318: ...ZyWALL 70 User s Guide 318 Chapter 18 Static Route ...
Страница 324: ...ZyWALL 70 User s Guide 324 Chapter 19 Policy Route ...
Страница 340: ...ZyWALL 70 User s Guide 340 Chapter 20 Bandwidth Management ...
Страница 376: ...ZyWALL 70 User s Guide 376 Chapter 22 Remote Management ...
Страница 390: ...ZyWALL 70 User s Guide 390 Chapter 24 Logs Screens Figure 194 Log Settings ...
Страница 413: ...ZyWALL 70 User s Guide Chapter 25 Maintenance 413 Figure 216 Restart Screen ...
Страница 414: ...ZyWALL 70 User s Guide 414 Chapter 25 Maintenance ...
Страница 440: ...ZyWALL 70 User s Guide 440 Chapter 28 WAN and Dial Backup Setup ...
Страница 456: ...ZyWALL 70 User s Guide 456 Chapter 31 DMZ Setup ...
Страница 460: ...ZyWALL 70 User s Guide 460 Chapter 32 Route Setup ...
Страница 470: ...ZyWALL 70 User s Guide 470 Chapter 33 Remote Node Setup ...
Страница 522: ...ZyWALL 70 User s Guide 522 Chapter 39 System Information Diagnosis ...
Страница 538: ...ZyWALL 70 User s Guide 538 Chapter 40 Firmware and Configuration File Maintenance ...
Страница 550: ...ZyWALL 70 User s Guide 550 Chapter 42 Remote Management ...
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Страница 574: ...ZyWALL 70 User s Guide 574 Chapter 45 Troubleshooting ...
Страница 582: ...ZyWALL 70 User s Guide 582 Appendix B Removing and Installing a Fuse ...
Страница 602: ...ZyWALL 70 User s Guide 602 Appendix D IP Subnetting ...
Страница 608: ...ZyWALL 70 User s Guide 608 Appendix F PPTP ...
Страница 626: ...ZyWALL 70 User s Guide 626 Appendix H Triangle Route ...
Страница 656: ...ZyWALL 70 User s Guide 656 Appendix K Importing Certificates ...
Страница 658: ...ZyWALL 70 User s Guide 658 Appendix L Command Interpreter ...
Страница 664: ...ZyWALL 70 User s Guide 664 Appendix M Firewall Commands ...
Страница 668: ...ZyWALL 70 User s Guide 668 Appendix N NetBIOS Filter Commands ...
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