Public IP addresses can be used for internal communication between Azure services and external communication over the internet. You can use IPv4 and IPv6 for public IP addresses, but support for IPv6 is limited. At the time of writing, you can only assign IPv6 addresses to external load balancers.

When an Azure resource is started or created, Azure will assign the public IP address to the network interface of the VNet. When an outbound connection is initiated, Azure will map the private IP address to the public IP addresses, which is also known as source network address translation (SNAT).

Azure assigns the public IP address to the network interface when the Azure resource is started or created. When an outbound connection is initiated, Azure will map the private IP address to the public IP address (SNAT). Returning traffic to the resource is allowed as well. Public IP addresses are typically used for VMs, internet-facing load balancers, VPN gateways, and application gateways. A maximum of 60 dynamic public IP addresses and 20 static public IP addresses is allowed per subscription. The first five static IP addresses are free to use.