There are two internet connections,
A: static dedicated ip goes straight
B: static dedicated ip, goes through PPPoE, I want to use as a backup connection.
There is a dlink dir 615 router with dd-wrt, a linux machine with two network cards, and a bunch of machines that get internet via wifi.
How to make a system in software or hardware so that when one Internet is turned off, all users turn on another? Perhaps you can buy any piece of iron that knows how.