D-Link DFL-1500 [79/271] One to one bidirectional type

DFL-900/1500 User Manual Chapter 7

NAT

Figure 7-6 NAT One-to-One type

As the above

Figure 7-6 illustrated, NAT One-to-One type means that each local PC is translated into a unique public IP address

when the packets are forwarded out through the DFL-1500. Take Connection1 for example. Its IP address and port are translated

from 192.168.40.1:2933 to 61.2.1.1:2933. But, when the packets of Connection2 are forwards out, the source IP address is translated

to another dedicated public IP address(61.2.1.2:7896).

7.5.4 One-to-One (bidirectional) type

Figure 7-7 NAT One-to-One (bidirectional) type

As the above

Figure 7-7 illustrated, NAT One-to-One (bidirectional) type means that each local PC is translated into a unique public

IP address when the packets are forwarded out through the DFL-1500. Besides, when packets came from internet to LAN, they were

translated to the same private IP address too. Take Connection1 for example. Its IP address and port are translated from

192.168.40.1:2933 to 61.2.1.1:2933 in both ways. Accordingly, the source IP address and port of the Connection2 are translated

from 192.168.40.100:7896 to 61.2.1.2:7896 in both ways.

7.5.5 NAT modes & types

The following three NAT modes are supported by DFL-1500 now as the following Table 7-4.

NAT mode Description

None

If you choose this mode, the DFL-1500 will act as a pure router without performing any address

translation.

Basic

The DFL-1500 automatically performs Many-to-One NAT for all LAN/DMZ subnets. All IP addresses

with outgoing packets will be translated to the IP address of default WAN link automatically.

Full Feature

The DFL-1500 can be manually configured with Many-to-One, and Many-to-Many, One-to-One, and

bidirectional One-to-One rules to do policy-based NAT. Here policy-based NAT means that you can fully

decide which zone (LAN, DMZ) will do the IP NAT and which zone (LAN, DMZ) will just do the pure IP

routing without IP translation.

Table 7-4 NAT modes overview