Ultimate Multi-WAN Failover Guide with Ubiquiti UniFi UCG-Fiber
Achieving 100% network uptime requires a solid Multi-WAN strategy. The Ubiquiti UniFi UCG-Fiber is an excellent gateway for managing multiple internet sources. This guide covers how to set up a robust three-tier failover system.
The Setup Architecture
A highly resilient network requires diverse connection types to prevent a single point of failure. A reliable architecture utilizes:
- WAN1 (Primary): Toya (Fiber Optic) – Offers the lowest latency and highest bandwidth.
- WAN2 (Secondary / Failover 1): Starlink – Provides independent satellite routing if the local terrestrial infrastructure fails.
- WAN3 (Tertiary / Failover 2): ZTE 5G Modem – Acts as the final backup utilizing cellular towers.
Recommended Equipment
For optimal integration with UniFi gear, the external modems must support bridge mode or IP passthrough to avoid Double NAT issues:
- Starlink: The Standard (Gen 3) with the official Ethernet Adapter, or the High Performance business model. Both allow bypassing the default Starlink router.
- ZTE 5G Modem: The ZTE MC889 outdoor ODU (Outdoor Unit). It is powered via PoE, handles harsh weather conditions, and provides a clean bridge mode directly to the UCG-Fiber.
Installation and Mandatory Grounding
When deploying Starlink and a 5G modem on a metal mast high above the roofline, strict electrical safety protocols must be followed:
- Lightning Protection: The metal mast must be connected directly to the building’s grounding system (earth rod) using a copper wire of appropriate cross-section (e.g., 16mm²).
- Surge Protection Panels: Outdoor Ethernet cables (STP – Shielded Twisted Pair) acting as antennas for lightning induction must not plug directly into core network switches. Cables should be routed down to the central distribution rack—often located in a secure, climate-stable environment like a cellar—and terminated on dedicated PoE surge protection panels before patching into the UCG-Fiber.
- Cable Management: Ensure outdoor-rated, UV-resistant shielded cables are used.
UniFi OS Configuration
- Navigate to Settings > Internet in the UniFi Network application.
- Select the Primary (WAN1) connection and assign it to the port where the Toya fiber is connected (e.g., via an SFP module).
- Add Secondary (WAN2) for Starlink. Under advanced settings, configure Load Balancing to Failover Only (to save power/data) or Distributed if concurrent usage is preferred.
- Add Tertiary (WAN3) for the ZTE 5G modem, setting its priority lower than Starlink.
- Adjust Echo Server settings (e.g., pinging 1.1.1.1 and 8.8.8.8) to ensure the UCG-Fiber accurately detects an outage and initiates the failover seamlessly.
Summary
This guide outlines the implementation of a resilient triple-WAN failover system using the Ubiquiti UniFi UCG-Fiber. By combining a fiber-optic primary connection (Toya) with satellite (Starlink) and cellular (ZTE 5G) backups, a constant internet connection is maintained. The article emphasizes the necessity of professional grounding for roof-mounted equipment and provides technical steps for configuring load balancing and echo servers within the UniFi OS environment.
