How to Configure One2One NAT Rule

User Requirements
A business uses a UTT router to connect to the Internet through a static IP Internet connection, with multiple public IP addresses. It is required that all the employees' computers share a single public IP address to access the Internet, while the remaining public IP addresses are used for internal servers that users on the Internet can access.
 
Network Topology
 

In this example, the ISP provides eight public IP addresses (from 202.1.1.128/29 to 202.1.1.1.135/29), which are assigned as follows:
UTT Router
WAN IP Address: 202.1.1.130/29
LAN IP Address: 192.168.16.1/24
Gateway IP Address: 202.1.1.129/29
Four Internal Servers
Real IP Addresses: 192.168.16.200/24 to 192.168.16.203/24
External IP Addresses: 202.1.1.131/29 to 202.1.1.134/29
Note that 202.1.1.128/29 and 202.1.1.1.135/29 cannot be used as they are the subnet number and broadcast address respectively.
 
Configuration Steps
Login to the Web UI of the UTT router, and then follow these steps.
 
Configuring Internet Connection
First you need to configure a static IP Internet connection that internal hosts use to access the Internet. The steps are as follows:
 
Go to the Basic > WAN > WAN1 page.
Select Static IP from the Connection Type drop-down list, see the following figure.
 
 
Enter 202.1.1.130, 255.255.255.248 and 202.1.1.129 in the IP Address, Subnet Mask and Default Gateway text boxes respectively.
Configure other parameters as required.
Click the Save button to save the settings.
Creating One2One NAT Rule
Next you need to create a One2One NAT rule for the four internal servers to be accessible from the Internet. The steps as follows:
Go to the NAT > NAT Rule > NAT Rule Settings page.
Select One2One from the NAT Type drop-down list, see the following figure.
 
 
Enter 202.1.1.131 in the Start External IP Address text box.
Enter 192.168.16.200 and 192.168.16.203 in the Start Internal IP Address and End Internal IP Address text boxes respectively.
Select WAN1 from the Bind to drop-down list.
Click the Save button to save the settings.
 
Conclusion
The configuration is now complete. Then all the internal hosts can share the Internet connection to access the Internet, and outside users can access the four internal servers using public IP addresses.