How to switch providers correctly in Mikrotik when one of them crashes?

Question

Computer networks

There is an industrial Mikrotik CCR series for 24 ports. 4 Internet providers are used, one of which (the fourth) is connected to Mikrotik via a GRE tunnel. The remaining three are standard - static IP addresses are registered in Addresses and that's it.

Tell me how to make sure that if all three providers with a static IP fall down, then the provider with the GRE tunnel automatically starts distributing the Internet?

Now it's done so that the GRE tunnel of the fourth provider is in the bridge with a local interface (for LAN).

Or what's the best way to do it? How are you doing? So that the interfaces rise in a certain order if one fails (lays down).

I know that the metric is being used. But how to do it in a modern way? Thanks in advance for your advice!

Answer 1

Oh damn. Was Google blocked too?
https://habr.com/ru/post/463813/
An interesting solution with the gre tunnel, but it is not clear how it is configured. Can you show me the config?
export

Answer 2

https://habr.com/ru/post/313342/

Answer 3

I have 2 providers. I switch simply by methods in routes. When 1 gateway is unavailable, another route is switched on. And everything works. I do not think that with 4 providers it is somehow different.