subnetMappings

The IDs of the subnets. You can specify only one subnet per Availability Zone. You must specify either subnets or subnet mappings, but not both.

[Application Load Balancers] You must specify subnets from at least two Availability Zones. You can't specify Elastic IP addresses for your subnets.

[Application Load Balancers on Outposts] You must specify one Outpost subnet.

[Application Load Balancers on Local Zones] You can specify subnets from one or more Local Zones.

[Network Load Balancers] You can specify subnets from one or more Availability Zones. You can specify one Elastic IP address per subnet if you need static IP addresses for your internet-facing load balancer. For internal load balancers, you can specify one private IP address per subnet from the IPv4 range of the subnet. For internet-facing load balancer, you can specify one IPv6 address per subnet.

[Gateway Load Balancers] You can specify subnets from one or more Availability Zones. You can't specify Elastic IP addresses for your subnets.