ipAddressType

The IP address type. Internal load balancers must use ipv4.

[Application Load Balancers] The possible values are ipv4 (IPv4 addresses), dualstack (IPv4 and IPv6 addresses), and dualstack-without-public-ipv4 (public IPv6 addresses and private IPv4 and IPv6 addresses).

Application Load Balancer authentication supports IPv4 addresses only when connecting to an Identity Provider (IdP) or Amazon Cognito endpoint. Without a public IPv4 address the load balancer can't complete the authentication process, resulting in HTTP 500 errors.

[Network Load Balancers and Gateway Load Balancers] The possible values are ipv4 (IPv4 addresses) and dualstack (IPv4 and IPv6 addresses).