Enumeration: ip_address_type
Modes of exposing IPs on the load balancer use "dualstack" for exposing both IPv4 and IPv6 addresses
See
https://aws.amazon.com/premiumsupport/knowledge-center/elb-configure-with-ipv6/
Columns
• DUALSTACK = "dualstack"
• IPV4 = "ipv4"