Samsung Ubigate iBG3026 Configuration Manual page 284

CHAPTER 23. Firewall NAT
Static NAT also requires a public address from the upstream service provider.
Individual PCs within a LAN are assigned RFC 1918 reserved IP addresses to
enable access to other PCs within the LAN. The Ubigate iBG3026 is
configured with static mapping, which maps the internal RFC 1918 IP
addresses for each PC to the appropriate public IP address.
Then when traffic is sent to the public address listed in the static mapping, the
Ubigate iBG3026 forwards the packets to the correct PC within the LAN,
according to the mapping relationship established.
Figure 23.7 illustrates dynamic and static NAT. The static translation between
192.168.1.6 and 100.1.1.6 automatically matches the port addresses, thus a
request destined for 100.1.1.6 tcp port 25 is translated to 192.168.1.6 tcp port
25 and so on.
244
Internet
100.1.1.1/29
192.168.1.254/24
10/100 BaceT Ethernet
Workstation Workstation
192.168.1.1/24 192.168.1.2/24
Figure 23.7 Dynamic and Static NAT
FTP, SMTP, HTTP Server
192.168.1.6/24
Workstation Workstation
192.168.1.3/24 192.168.1.5/24
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