Nat Mapping Types; Figure 201 Port Restricted Cone Nat Example - ZyXEL Communications ZYWALL 2 PLUS User Manual

Chapter 17 Network Address Translation (NAT)

Figure 201 Port Restricted Cone NAT Example

17.1.6 NAT Mapping Types

NAT supports five types of IP/port mapping. They are:
• One to One: In One-to-One mode, the ZyWALL maps one local IP address to one global
IP address.
• Many to One: In Many-to-One mode, the ZyWALL maps multiple local IP addresses to
one global IP address. This is equivalent to SUA (i.e., PAT, port address translation),
ZyXEL's Single User Account feature (the SUA option).
• Many to Many Overload: In Many-to-Many Overload mode, the ZyWALL maps the
multiple local IP addresses to shared global IP addresses.
• Many One to One: In Many-One-to-One mode, the ZyWALL maps each local IP address
to a unique global IP address.
• Server: This type allows you to specify inside servers of different services behind the
NAT to be accessible to the outside world although, it is highly recommended that you use
the DMZ port for these servers instead.
Port numbers do not change for One-to-One and Many-One-to-One NAT
mapping types.
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