OpenWRT Router Switches Starlink to 4G in 1 Second During Outages
Updated
Updated · MUO - MakeUseOf · Jul 21
OpenWRT Router Switches Starlink to 4G in 1 Second During Outages
1 articles · Updated · MUO - MakeUseOf · Jul 21
Summary
A Starlink Mini home network was configured to fail over automatically to a 4G USB modem, with tests showing internet interruptions of no more than about 1 second.
MWAN3 on an OpenWRT edge router monitors both links through multiple tracking addresses, keeps Starlink as the primary path, and shifts traffic to 4G only when Starlink is judged offline.
The setup required passing the modem into an OpenWRT VM, adding USB networking drivers, creating a second DHCP WAN interface, and attaching it to existing firewall rules.
The backup targets frequent power cuts, storms, and heatwaves that can knock out Starlink; devices stay on the same LAN, SSID, gateway, and DNS without manual reconnection.
The arrangement is failover rather than bonded service, so calls, VPNs, and downloads can still break when the public IP changes, but essential connectivity remains available.