How to configure WAN IP Alias for Omada Gateway

This article applies to: This feature is supported on gateways with Omada Controller version 5.13 and above.

WAN IP Alias is used to configure multiple IP aliases for the WAN port, primarily used together with NAT.

1. In Standalone mode, you can go to Network > WAN, then go to the corresponding port page, and click WAN IP Alias to add additional IP addresses for the corresponding WAN port.

2. In Controller mode, you can go to Setting > Wired Networks > Internet > Advanced Settings, then go to the corresponding port page, and click WAN IP Alias to add additional IP addresses for the corresponding WAN port.

Should I use WAN IP Alias?

WAN IP Alias is recommended in the following scenarios:

1. When there are two or more servers of the same type in the internal network, such as two HTTP servers, and you want to expose both servers on port 80 and map them through a single WAN interface.

2. The IP address you wish to expose is fixed.

How does it work?

After enabling and configuring WAN IP Alias, the configured IP will serve as an additional IP for that WAN port. Users can set up multiple NAT rules to achieve access to multiple servers of the same type within the internal network. This configuration will also help maintain a fixed external IP for the access.

WAN Alias IP1:80---->http server1 Internal IP:80

WAN Alias IP2:80---->http server2 Internal IP:80

1. In Standalone mode, go to Transmission > NAT > Virtual Servers to add NAT rules.

For server 1: Select the WAN port that the Alias IP is for, set the WAN IP to the configured Alias IP 1, configure the external port and internal port to 80.

For server 2: Select the WAN port that the Alias IP is for, set the WAN IP to the configured Alias IP 2, configure the external port and internal port to 80.

In this scenario, with only one WAN port enabled and both servers exposed on port 80, you can access HTTP Server 1 via192.168.136.191:80 and HTTP Server 2 via192.168.136.190:80.

2. In Controller mode, go to Transmission > Port Forwarding to add NAT rules.

All configurations are the same as Standalone mode. If you only need to map port 80, do not enable DMZ

Notes:

When using WAN IP Alias, please note the following. These are not specific to Omada Gateway but are protocol related.

1. The configured Alias IP should preferably be in the same subnet as the main IP of the WAN port where the dial-up connection is established.

2. Avoid conflicts between the configured Alias IP and other IPs in the same subnet as the WAN port.

3. Avoid conflicts between the subnet of the configured Alias IP and the LAN subnet of the Gateway.

FAQ (Frequently Asked Questions)

Q1. After configuring WAN IP Alias, will my network traffic be sent with the Alias IP as the source IP on the internet?

A1. No, the WAN port will only use the internet dial-up IP for Source NAT (SNAT) when sending traffic on the internet.

Q2. Can I change the Alias IP?

A1. You can change the Alias IP, but note that changing it will result in the corresponding NAT rules being deleted. You will need to reconfigure the NAT rules.

Q3. Will multiple Alias IPs affect my network performance?

A1. As long as the NAT traffic remains the same, the number of Alias IPs will not affect the performance of network traffic.

To get more details of each function and configuration, please go to Download Center to download the manual of your product.