2 main gateways on linux ubuntu?

Question

Computer networks

How to make 2 default gateways per network interface in netplan?
registered routes and a metric in Netplan. But it does not switch to the second gateway if you disable the first one.

network:
    ethernets:        
        ens33:
            dhcp4: no
            addresses:
                - 150.150.150.4/24
            routes:
                - to: 0.0.0.0/0
                  via: 150.150.150.2
                  metric: 100
                - to: 0.0.0.0/0
                  via: 150.150.150.3
                  metric: 101

[email protected]:~# routel
         target            gateway          source    proto    scope    dev tbl
        default      150.150.150.2                   static           ens33
        default      150.150.150.3                   static           ens33

Answer 1

Write a script that will be run by cron, check availability and reconfigure the route.
Of course (without a script) it will work under two conditions:
1) each gateway is connected through its own interface;
2) the link must physically fall on one of the interfaces, then the route will go through the other, in accordance with the metric; if there is no ping, but there is a link - even if you crack, it will be hammered by the minimum metric. I agree that this is pretty dumb for 2020, but as it is.
PS well, or use all sorts of dynamic routing protocols, this is a separate conversation.