Azure VPN Gateway
1. VPN Gateway
Azure VPN Gateway is a service that can be used to send encrypted traffic between an Azure virtual network and on-premises locations over the public Internet. You can also use VPN Gateway to send encrypted traffic between Azure virtual networks over the Microsoft network.
- Site-to-site connection: A cross-premises IPsec/IKE VPN tunnel connection between the VPN gateway and an on-premises VPN device.

-
Point-to-site connection: lets you connect to your virtual network from a remote location, such as from a conference or from home.

-
VNet-to-VNet: An IPsec/IKE VPN tunnel connection between the VPN gateway and another Azure VPN gateway that uses a VNet-to-VNet connection type.

-
ExpressRoute + VPN Gateway: A combination of ExpressRoute + VPN Gateway connections (coexisting connections).


Public IP
- A VPN gateway requires a public IP address for communication.
- A zone-redundant gateway requires a public IP address that also supports zone-redundancy.