Which VPC subnets to choose while building a VPC
AWS gives us a lot of flexibility while designing the VPC network. AWS supports the following subnet blocks: /16 to /28. If you choose a /16 netmask, it will give you 65,536 Internet Protocol (IP) addresses, and if you decide on a /28 IP address, it will provide you with 16 addresses. Now, which subnet block to choose depends entirely upon your network requirements. Typically, companies choose a bigger subnet as this helps them if their infrastructure expands.
AWS now supports the addition of IPv4 classless inter-domain routing (CIDR) to your VPC. The default quota is 5, and the soft limit can be increased to 50 for IPv4. For IPv6, the default limit is 1, which can't be increased (hard limit). In order to add additional CIDR blocks to your VPC, we perform the following steps:
- Go to the VPC console at https://us-west-2.console.aws.amazon.com/vpc/home. Select the VPC to prod-vpc, as in this example, and click on Actions...