ipv6Cidrs

The IPv6 address, or range of IPv6 addresses (in CIDR notation) that are allowed to connect to an instance through the ports, and the protocol. Only devices with an IPv6 address can connect to an instance through IPv6; otherwise, IPv4 should be used.

The cidrs parameter lists the IPv4 addresses that are allowed to connect to an instance.

For more information about CIDR block notation, see Classless Inter-Domain Routing on Wikipedia.