Posted On: May 13, 2022

Amazon Web Services (AWS) announces the launch of multiple IPv6 classless inter-domain routing (CIDR) blocks in a Virtual Private Cloud (VPC), enabling customer to attach up to 5 prefixes to their VPCs. Before today, customers could add up to 5 IPv4 CIDR blocks and 1 IPv6 block. With this new feature, customers can now use multiple blocks to build logical separation within their VPCs with independent CIDR blocks. CIDR blocks can be associated from the Amazon provided pool and/or a pool of bring-your-own IPv6 addresses.

With IPv4 customers needed additional CIDR blocks to increase their address space within a VPC. With IPv6, address space should no longer be a concern. Customers can use multiple CIDR blocks to better segment their network infrastructure such as subnets, route tables, and security groups with different prefix ranges for different applications. With the ability to BYOIP, customers can launch one subnet from their own BYOIPv6 pool and another subnet with Amazon provided IP addresses. With BYOIP pools having the option to not advertise to the internet, customers can use these separate CIDRs to achieve clear separation of internal and external facing applications in their VPCs.

This feature is available in all AWS commercial and AWS GovCloud (US) Regions at no additional cost. For more information, please visit the VPC user guide.