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Chapter 8 Network Address Translation (NAT) Screens
NN47923-500
Note that inside/outside refers to the location of a host, while global/local refers to
the IP address of a host used in a packet. Thus, an inside local address (ILA) is the
IP address of an inside host in a packet when the packet is still in the local
network, while an inside global address (IGA) is the IP address of the same inside
host when the packet is on the WAN side.
summarizes this information.
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) 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. You can make designated servers on the LAN 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 Business Secure Router filters out all
incoming inquiries, thus preventing intruders from probing your network. For
more information about IP address translation, refer to
The IP Network Address
Translator (NAT)
(RFC 1631).
Table 23
NAT definitions
Term
Description
Inside
This refers to the host on the LAN.
Outside
This refers to the host on the WAN.
Local
This refers to the packet address (source or destination) as the packet
travels on the LAN.
Global
This refers to the packet address (source or destination) as the packet
travels on the WAN.
Note:
NAT never changes the IP address (either local or global) of an
outside host.
Содержание BSR252
Страница 28: ...28 Tables NN47923 500 ...
Страница 44: ...44 Chapter 1 Getting to know your Business Secure Router NN47923 500 ...
Страница 52: ...52 Chapter 2 Introducing the WebGUI NN47923 500 ...
Страница 70: ...70 Chapter 3 Wizard setup NN47923 500 ...
Страница 91: ...Chapter 5 System screens 91 Nortel Business Secure Router 252 Configuration Basics Figure 20 Time and Date ...
Страница 96: ...96 Chapter 5 System screens NN47923 500 ...
Страница 100: ...100 Chapter 6 LAN screens NN47923 500 Configuring IP Click LAN to open the IP screen Figure 22 LAN IP ...
Страница 111: ...Chapter 7 WAN screens 111 Nortel Business Secure Router 252 Configuration Basics Figure 26 WAN WAN ISP ...
Страница 114: ...114 Chapter 7 WAN screens NN47923 500 Figure 27 WAN IP ...
Страница 120: ...120 Chapter 7 WAN screens NN47923 500 Figure 31 Dial Backup Setup ...
Страница 128: ...128 Chapter 7 WAN screens NN47923 500 ...
Страница 152: ...152 Chapter 9 Static Route screens NN47923 500 ...
Страница 194: ...194 Chapter 11 Firewall screens NN47923 500 ...
Страница 210: ...210 Chapter 13 VPN NN47923 500 Figure 67 Summary IP Policies ...
Страница 222: ...222 Chapter 13 VPN NN47923 500 Figure 71 VPN Branch Office rule setup ...
Страница 231: ...Chapter 13 VPN 231 Nortel Business Secure Router 252 Configuration Basics Figure 72 VPN Branch Office IP Policy ...
Страница 249: ...Chapter 13 VPN 249 Nortel Business Secure Router 252 Configuration Basics Figure 78 VPN Client Termination ...
Страница 256: ...256 Chapter 13 VPN NN47923 500 Figure 81 VPN Client Termination advanced ...
Страница 260: ...260 Chapter 13 VPN NN47923 500 ...
Страница 264: ...264 Chapter 14 Certificates NN47923 500 Figure 83 My Certificates ...
Страница 270: ...270 Chapter 14 Certificates NN47923 500 Figure 85 My Certificate create ...
Страница 274: ...274 Chapter 14 Certificates NN47923 500 Figure 86 My Certificate details ...
Страница 282: ...282 Chapter 14 Certificates NN47923 500 Figure 89 Trusted CA details ...
Страница 298: ...298 Chapter 14 Certificates NN47923 500 ...
Страница 316: ...316 Chapter 16 IEEE 802 1x NN47923 500 ...
Страница 320: ...320 Chapter 17 Authentication server NN47923 500 Figure 106 Local User database edit ...
Страница 328: ...328 Chapter 17 Authentication server NN47923 500 ...
Страница 376: ...376 Chapter 20 Logs Screens NN47923 500 Figure 150 Log settings ...
Страница 386: ...386 Chapter 20 Logs Screens NN47923 500 ...
Страница 392: ...392 Chapter 21 Call scheduling screens NN47923 500 Figure 157 Applying Schedule Sets to a remote node ...
Страница 393: ...Chapter 21 Call scheduling screens 393 Nortel Business Secure Router 252 Configuration Basics ...
Страница 394: ...394 Chapter 21 Call scheduling screens NN47923 500 ...
Страница 409: ...Chapter 22 Maintenance 409 Nortel Business Secure Router 252 Configuration Basics Figure 170 Restart screen ...
Страница 410: ...410 Chapter 22 Maintenance NN47923 500 ...
Страница 430: ...430 Appendix A Troubleshooting NN47923 500 ...