[2023 December Tips & Tricks] Did You Know You Can Implement Dual WAN with Entry-level Models?

zyxel_Lin Posts: 73  Zyxel Employee
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edited December 2023 in Security Highlight

The USG FLEX series has been a long favorite of SMBs that needed a reliable security gateway that could balance multiple Internet connections. Despite being an entry-level, such as: ATP100(W)/USG FLEX 50/50AX/100(W)/100AX/USG20(W)-VPN, you can make use of either the SFP or the OPT port to add a secondary connection. In this article, we will take a closer look at how to convert an OPT interface to a WAN interface and the benefits of dual WAN.

Dual WAN (Wide Area Network) is a networking configuration that involves using two separate internet connections from different service providers or sources simultaneously. This setup offers several benefits, which can be particularly valuable in business and home network environments:

1. Load Balancing and Increased Bandwidth:

One of the primary advantages of dual WAN is load balancing. This means that network traffic is distributed across both connections, optimizing the use of available bandwidth. This results in improved network performance and ensures that no single connection is overwhelmed.

2. Redundancy and Failover:

Dual WAN provides network redundancy. If one connection fails or experiences issues, the other connection can automatically take over, ensuring uninterrupted internet access. This is critical for businesses that require high availability.

3. Enhanced Security:

With dual WAN, you can implement security features like a dedicated VPN (Virtual Private Network) on one connection while leaving the other for general internet use. This enhances security and isolates sensitive traffic from the public internet.

Overall, dual WAN configurations provide increased reliability, improved performance, and greater flexibility for managing internet connectivity.

How to Add Additional WAN Interfaces in ATP/USG FLEX Series?

On-Premises Firewalls

1. Choosing the Interface

Navigate to (1) Configuration> (2) Network> Interface> (3) Ethernet (4) Choose the interface that you want to convert to a WAN (5) Click “Edit”

2. "Converting" the Interface

• Set the Interface Type to “external”
• Give it a name under “Interface Name” (e.g. wan2)
• Switch the Zone to “WAN”
• If your WAN IP Assignment is Dynamic, set “IP Assignment” to Dynamic.
• If you plan to use PPPoE, then set it to “Static” and give it the following Parameters:
• IP Address:
• Subnet Mask:

On-cloud Firewalls

1. Set Up WAN Load Balancing

Navigate to Configure > Firewall > Port. Create WAN Group 2 and assign P5 to it.

2. Navigate to Configure > Firewall > interface and set IP address for both interfaces. Set IP address for both interfaces.

3. Navigate to Configure > Firewall > Routing. Turn on Backup interface and select OPT as Backup interface.