openwrt-wan-failover

This is a simple script/service that constantly pings your primary interface (WAN) and secondary interface (WWAN, though I suppose in practice it doesn't have to be a wireless WAN link).

Install it with the install.sh script on your OpenWRT device, and either reboot, or start it immediately with service wan-failover start.

There is currently no UI to configure it; use uci or manually edit the provided sample configuration file before installing.

Before starting the service, you should set your primary interface's metric to 10, and the backup to 20.