How to backup a network connection on multiple routers with the same IP?

Question

Computer networks

There are several branches.

In each branch on Mikrotik.

All branches are connected to one provider.

The provider gives two VLANs, conditionally VID 10 for our local traffic, VID 20 for Internet access.

The provider has allocated a public network /30, i.e. 1 ip is ours, the second is the gateway on the provider's side, the network lives in VID 20.

Now the Internet connection is terminated in one branch, traffic from other branches is flowing right there, that is, there is an interface with VID 20 only on the main branch.

The task is to make sure that when the main branch fails, the Internet connection in the other branches does not fall. But it will not be possible to raise the interface with VID 20 with the same IP on all branches, for obvious reasons.

Question: is it possible on Mikrotik to send one interface to Disabled when a certain default is available and to raise it, if it is unavailable, respectively?

Answer 1

Maybe in a simple way - detect internet ?

Answer 2

Netwatch plus a script for it?