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ZyAIR G-2000 Plus User’s Guide
137
Chapter 10 Single User Account (SUA) / Network Address Translation (NAT)
10.1.2 What NAT Does
In the simplest form, NAT changes the source IP address in a packet received from a
subscriber (the inside local address) to another (the inside global address) before forwarding
the packet to the WAN side. When the response comes back, NAT translates the destination
address (the inside global address) back to the inside local address before forwarding it to the
original inside host. Note that the IP address (either local or global) of an outside host is never
changed.
The global IP addresses for the inside hosts can be either static or dynamically assigned by the
ISP. In addition, you can designate servers (for example a web server and a telnet server) on
your local network and make them accessible to the outside world. If you do not define any
servers (for Many-to-One and Many-to-Many Overload mapping), NAT offers the additional
benefit of firewall protection. With no servers defined, your ZyAIR filters out all incoming
inquiries, thus preventing intruders from probing your network. For more information on IP
address translation, refer to
RFC 1631
,
The IP Network Address Translator (NAT)
.
10.1.3 How NAT Works
Each packet has two addresses – a source address and a destination address. For outgoing
packets, the ILA (Inside Local Address) is the source address on the LAN, and the IGA (Inside
Global Address) is the source address on the WAN. For incoming packets, the ILA is the
destination address on the LAN, and the IGA is the destination address on the WAN. NAT
maps private (local) IP addresses to globally unique ones required for communication with
hosts on other networks. It replaces the original IP source address (and TCP or UDP source
port numbers for Many-to-One and Many-to-Many Overload NAT mapping) in each packet
and then forwards it to the Internet. The ZyAIR keeps track of the original addresses and port
numbers so incoming reply packets can have their original values restored. The following
figure illustrates this.
Note:
NAT never changes the IP address (either local or global)
of an outside host.
Содержание ZyAIR G-2000 Plus
Страница 1: ...ZyAIR G 2000 Plus 802 11g Wireless 4 port Router User s Guide Version 3 60 12 2004...
Страница 2: ......
Страница 8: ...ZyAIR G 2000 Plus User s Guide 7 Customer Support...
Страница 22: ...ZyAIR G 2000 Plus User s Guide 21 Table of Contents...
Страница 36: ...ZyAIR G 2000 Plus User s Guide 35 Preface...
Страница 44: ...ZyAIR G 2000 Plus User s Guide 43 Chapter 1 Getting to Know Your ZyAIR...
Страница 88: ...ZyAIR G 2000 Plus User s Guide 87 Chapter 6 Wireless Configuration and Roaming...
Страница 124: ...ZyAIR G 2000 Plus User s Guide 123 Chapter 8 Internal RADIUS Server...
Страница 152: ...ZyAIR G 2000 Plus User s Guide 151 Chapter 10 Single User Account SUA Network Address Translation NAT...
Страница 156: ...ZyAIR G 2000 Plus User s Guide 155 Chapter 11 Static Route Screens...
Страница 192: ...ZyAIR G 2000 Plus User s Guide 191 Chapter 14 Firewalls...
Страница 201: ...ZyAIR G 2000 Plus User s Guide Chapter 15 Firewall Screens 200 Figure 83 Creating Editing A Firewall Rule...
Страница 206: ...ZyAIR G 2000 Plus User s Guide 205 Chapter 15 Firewall Screens Figure 88 My Service Rule Configuration...
Страница 210: ...ZyAIR G 2000 Plus User s Guide 209 Chapter 15 Firewall Screens...
Страница 214: ...ZyAIR G 2000 Plus User s Guide 213 Chapter 16 Content Filtering...
Страница 221: ...ZyAIR G 2000 Plus User s Guide Chapter 17 Certificates 220 Figure 93 My Certificate Create...
Страница 224: ...ZyAIR G 2000 Plus User s Guide 223 Chapter 17 Certificates Figure 94 My Certificate Details...
Страница 230: ...ZyAIR G 2000 Plus User s Guide 229 Chapter 17 Certificates Figure 97 Trusted CA Details...
Страница 235: ...ZyAIR G 2000 Plus User s Guide Chapter 18 Log Screens 234 Figure 99 Log Settings...
Страница 240: ...ZyAIR G 2000 Plus User s Guide 239 Chapter 18 Log Screens...
Страница 252: ...ZyAIR G 2000 Plus User s Guide 251 Chapter 19 Maintenance Figure 114 Restart Screen...
Страница 264: ...ZyAIR G 2000 Plus User s Guide 263 Chapter 22 Menu 2 WAN Setup...
Страница 274: ...ZyAIR G 2000 Plus User s Guide 273 Chapter 23 LAN Setup...
Страница 280: ...ZyAIR G 2000 Plus User s Guide 279 Chapter 24 Internet Access...
Страница 290: ...ZyAIR G 2000 Plus User s Guide 289 Chapter 25 Remote Node Configuration...
Страница 338: ...ZyAIR G 2000 Plus User s Guide 337 Chapter 32 System Security...
Страница 350: ...ZyAIR G 2000 Plus User s Guide 349 Chapter 33 System Information and Diagnosis...
Страница 362: ...ZyAIR G 2000 Plus User s Guide 361 Chapter 34 Firmware and Configuration File Maintenance...
Страница 376: ...ZyAIR G 2000 Plus User s Guide 375 Chapter 37 Call Scheduling...
Страница 380: ...ZyAIR G 2000 Plus User s Guide 379 Appendix B...
Страница 392: ...ZyAIR G 2000 Plus User s Guide 391 Appendix C...
Страница 396: ...ZyAIR G 2000 Plus User s Guide 395 Appendix D...
Страница 404: ...ZyAIR G 2000 Plus User s Guide 403 Appendix E...
Страница 406: ...ZyAIR G 2000 Plus User s Guide 405 Appendix F...
Страница 413: ...ZyAIR G 2000 Plus User s Guide Appendix H 412 Figure 235 ESS Provides Campus Wide Coverage...
Страница 414: ...ZyAIR G 2000 Plus User s Guide 413 Appendix H...
Страница 417: ...ZyAIR G 2000 Plus User s Guide Appendix I 416 Figure 237 Sequences for PEAP MS CHAP V2 Authentication...
Страница 418: ...ZyAIR G 2000 Plus User s Guide 417 Appendix I...
Страница 430: ...ZyAIR G 3000 User s Guide 429 Index ZyNOS F W Version 351 ZyXEL s Firewall Introduction 179...