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...