7.1 NAT
Setting
We can classify IP addresses in two kinds: local (private) and global (public). Local IP addresses
cannot be used on the Internet and are mostly used on Local Area Networks (LANs). Public
addresses are valid on the Internet and must be properly registered so information can be sent to
them. Configure of NAT can be find under the
Configuration Security
-
Traffic Security
menu.
Configuration TAINET WANpro 2000i Version 3.01
================================================================================
System Interface Routing Table [Security]
Security Configuration
+-----------------------------NAT------------------------------+
| |
| Static NAT (Network Address Translation) [disable] |
| |
| NAPT (Network Address Port Translation) |
| Public IP [0.0.0.0 ] |
| NetMask [0.0.0.0 ] |
| Proxy Port List [disable] |
| |
+--------------------------------------------------------------+
Press: SPACE to select
TAB,ENTER:next field '<':left '>':right ESC:abort
Figure 7-1 NAT Configuration Menu
NAT, described in RFC 3022, allows local IP addresses on the LAN to be converted into global
IP addresses on the Internet.
WANpro use NAPT (Network Address Port Translation) device maps ALL the local IP addresses
into a SINGLE global IP address that assigned by an ISP. The PAT will perform a mapping
between local port addresses and global port addresses from a pool of available port addresses.
The advantage of this scheme, in addition to those mentioned above, is cost savings; only
one ISP account and IP address is required.
In addition, the PAT scheme provides privacy since the internal LAN is unavailable to hosts on
the Internet; all they can see is the single IP address interface provided by the PAT device.
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