Samsung Ubigate iBG3026, Configuration Manual

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CHAPTER 23. Firewall NAT
240
© SAMSUNG Electronics Co., Ltd.
NAT configuration Examples
Dynamic NAT (many to many)
In dynamic(many-to-many) NAT type, multiple source IP addresses in the
corporate network will be mapped to multiple NAT IP addresses(not
necessarily of equal number). For a set of local IP address from 10.1.1.1 to
10.1.1.4 there will be a set of NAT IP address from 60.1.1.1 to 60.1.1.2. In
case of many-to-many NAT, only IP address translation takes place, i.e., if a
packet travels from 10.1.1.1 to yahoo.com, Firewall only substitutes the
source address in the IP header with one of the NAT IP address and the source
port will be the same as the original. If traffic emanates from the same client
to any other server, the same NAT IP address is assigned. The advantage is
that the NAT IP addresses are utilized in a better and optimum manner
dynamically.
If a NAT IP address cannot be allocated dynamically at the connection
creation time, the packet would be dropped.
Figure 23.4 Dynamic NAT
The dynamic NAT configuration shown in Figure 25.4 includes:
Private network addresses:10.1.1.1-10.1.1.4
Public(NAT) IP address range: 60.1.1.1-60.1.1.2
10.1.1.1
10.1.1.2
10.1.1.3
60.1.1.1.60.1.1.2
Internet
OPAL