Allied Telesis AT-WA7500 - Manual (Page 60)

3 - Configuring the Ethernet Network
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When the access point receives a frame with its IP address, it identifies
the need for address translation by inspecting the destination port
number. If the port number is within the pool reserved for NAT
operation, it looks up the original MAC address, IP address, and port
number. The frame is then modified and forwarded to the end device.
NAT operation is disabled or enabled automatically depending on the
continuous range of addresses you enter into the DHCP server. NAT is
disabled if the range of addresses to be given to DHCP clients is on the
same subnet as the access point. NAT is enabled if the range of
addresses to be given to DHCP clients is not on the same subnet as the
access point; thus, you are creating a virtual network and the DHCP
server will also perform NAT translation.
When NAT operation is enabled, the access point uses the low address in
the range of addresses as its own. The DHCP/NAT clients also use this
address as their router IP address. These clients can configure the access
point using this internal IP address or the normal external IP address.
To configure the access point as a NAT server
1. From the Main Menu, select TCP/IP Settings. The TCP/IP Settings
screen appears.
2. Verify that the IP Address field and IP Subnet Mask field are
configured. For help, see Configuring the TCP/IP Settings on page
54.
3. In the DHCP Mode field, choose This AP is a DHCP Server.
4. Select Submit Changes to save your changes.
5. Select DHCP Server Setup and enter a range of IP addresses that are
not on the same subnet as the access point.
6. Select Submit Changes to save your changes. To activate your
changes, select Save/Discard Changes from the menu bar then Save
Changes and Reboot. For help, see Saving Configuration Changes
on page 41.