Nat Menu Command - Siemens SCALANCE W788-1PRO Operating Instructions Manual

Configuration Using Web Based Management and the Command Line Interface
6.5.7

NAT Menu Command

N ote
This m enu command is available only with the following variants:
• SCALANCE W746-1PRO
• SCALANCE W747-1RR
•
SCALANCE W78x (client mode only
What is NAT?
With Network Address Tra
re placed by another. NAT is normally used on a gateway between a private LAN
and an extern
interna l LAN is changed to an external global IP address by a NAT device at the
gateway.
To translate the internal into the global IP address, the NAT device maintains a
translation list.
What is NA PT?
In Network Address Port Translation (NAPT) or Port Address Translation (PAT),
several internal source IP addresses are translated into the same external source
IP address. To identify the individual source nodes, the port of the source device
also stored in the translatio
addres s.
If several local clients send a query to the same external destination IP address
over the NAT gateway, the gateway enters
the header of these forwarded frames. Since the forwarded frames have the same
g lobal source IP address, the NAT gateway assigns the frames to the clients using
differe nt port number.
Operating Instructions SCALANCE W78x
C79000-G8976-C184-07
nslation (NAT), the IP address in a data packet is
al network with globally valid IP addresses. A local IP address of the
n list of the NAT gateway and translated for the external
)
its own external source IP address in
is
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