Four
The external VPN gateway has four public IP addresses; at the time of writing this API, the AWS virtual private gateway is an example which has four public IP addresses for high availability connections; there should be two VPN connections in the AWS virtual private gateway , each AWS VPN connection has two public IP addresses; please make sure to put two public IP addresses from one AWS VPN connection into interfaces 0 and 1 of this external VPN gateway, and put the other two public IP addresses from another AWS VPN connection into interfaces 2 and 3 of this external VPN gateway. When displaying highly available configuration status for the VPN tunnels connected to FOUR_IPS_REDUNDANCY external VPN gateway, Google will always detect whether interfaces 0 and 1 are connected on one interface of HA Cloud VPN gateway, and detect whether interfaces 2 and 3 are connected to another interface of the HA Cloud VPN gateway.