Configuring Nat - AudioCodes MP-20 Series User Manual

User's Manual
15.7

Configuring NAT

The device features a configurable Network Address Translation (NAT) and Network
Address Port Translation (NAPT) mechanism, allowing you to control the network
addresses and ports of packets routed through your gateway. When enabling multiple
computers on your network to access the Internet using a fixed number of public IP
addresses, you can statically define which LAN IP address will be translated to which NAT
IP address and/or ports.
By default, the device operates in NAPT routing mode. However, you can control your
network translation by defining static NAT/NAPT rules. Such rules map LAN computers to
NAT IP addresses. The NAT/NAPT mechanism is useful for managing Internet usage in
your LAN, or complying with various application demands. For example, you can assign
your primary LAN computer with a single NAT IP address, in order to assure its permanent
connection to the Internet. Another example is when an application server with which you
wish to connect, such as a security server, requires that packets have a specific IP address
– you can define a NAT rule for that address.

To define a NAT:
1. From the menu bar, click the Security menu, and in the screen 'Security', click the
NAT tab; the screen 'NAT' opens.
2. Before configuring NAT/NAPT rules, you must first enter the additional public IP
addresses obtained from your ISP as your NAT IP addresses, in the 'NAT IP
Addresses Pool' section. The primary IP address used by the WAN device for dynamic
NAPT should not be added to this table.
a. To add a NAT IP address, click the New
b. From the 'Network Object Type' drop-down list, select between IP address,
subnet or range, and then enter the information respectively, and click OK to
save the settings.
Version 4.4.3
Figure 15-21: NAT Screen
Figure 15-22: Adding a NAT IP Address
253
icon; the 'Edit Item' screen appears.
MP-20x Multimedia Home Gateway
15. Security