Failover - Multiple gateways

[m4rk0]

Hello everyone.

My ISP has few gateways how can I setup Failover to change gateway?

Thank You.

P.S. When I set static WAN IP for example: 192.168.1.1 / 16 and my GATEWAY is 192.168.0.100 I don't have internet connection, but when I change WAN IP for example to 192.168.0.11 it works.
Why /16 doesn't affects on this?