Use Case 2: Forward LAN traffic to the External Network through the Gateway after HA Failover

The interface IP (aka floating IP) in the Azure HA environment is set as the default gateway of the LAN subnet. When LAN traffic forwards to the external network through the gateway, traffic will automatically flow into the active HA Azure firewall without flowing into the standby HA Azure firewall. This is because the interface IP always floats to the active HA Azure firewall. After HA failover, the active HA Azure firewall will change to the standby firewall, so traffic will be forwarded to the newly active firewall.