Nat Mapping Types - ZyXEL Communications P-660R-T1 Support Notes

we call this fe ature as '
please refer to RFC 163
How NAT works
If we define the local IP
global IP a ddresses as t
term 'inside' refers to th
by mapping the ILA to the IGA required for communication with hosts on other
networks. It replaces
numbers) and then f orw
as if they had come fro
keeps track of the origi
have their original values restored.

NAT Mapping Types

NAT supports five types of IP/port mapping. They are:
One to One
In One-to-One mode, the P-660 maps one ILA to one IGA.
Many to One
In Many-to-One mode, the P-660 maps multiple ILA to one IGA. This is equivalent to
SUA (i.e., PAT, port address translation
previous ZyNOS routers supported (the SUA only option in today's routers).
Many to Many Overload
In M any-to-Many Overload mode, the P-660 maps the multiple ILA to shared IGA.
All contents copyright © 2005 ZyXEL Communications Corporation.
Multi-NAT'. For mo
1, The IP Network
addresses as the I
he Inside Global A
e set of networks that are subject to translation. NAT operates
th e original IP source
ards each packet to
m the NAT system itself (e.g., the P-660 router). T
nal addresses and p
), ZyXEL's Single User Account feature that
P-660 series Support Notes
re info rmation on IP address translation,
Address Translator (NAT).
nternal Local Addresses (ILA) and the
dd ress (IGA) , see the following figure. The
address (and TCP or UDP source port
the Internet ISP, thus making them appear
ort numbers so incoming reply packets can
he P-660
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