IPv6 gateways help you build a secure and reliable IPv6 environment.
Scenario 1: Enable IPv6 for a virtual private cloud (VPC) and build an isolated IPv6 environment
If you enable IPv6 for an existing VPC, the VPC supports both IPv4 and IPv6. You can assign IPv6 addresses to the Elastic Compute Service (ECS) instances on which services are deployed. This way, the ECS instances can use IPv4 addresses and IPv6 addresses. By default, the IPv6 address of an ECS instance can be used only for communication within the VPC.
Scenario 2: Enable ECS instances in a VPC to communicate with the Internet by using IPv6 addresses
After you enable IPv6 Internet bandwidth for an IPv6 address, the IPv6 address can be used for communication over the Internet. IPv6 traffic between ECS instances in a VPC and IPv6 networks traverses the IPv6 gateway. The IPv6 gateway processes inbound and outbound IPv6 traffic.
Scenario 3: Configure egress-only rules to manage IPv6 traffic
If you want an ECS instance to access IPv6 clients and deny access from IPv6 clients,