From the course: VPC Networking on AWS: Configuration, Security, and Connectivity

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Primary and secondary CIDR blocks

Primary and secondary CIDR blocks - Amazon Web Services (AWS) Tutorial

From the course: VPC Networking on AWS: Configuration, Security, and Connectivity

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Primary and secondary CIDR blocks

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- [Instructor] This lesson is dedicated to looking at the concept of CIDR blocks. We've talked about CIDR blocks in other parts of the class, but I wanted to separate it out just in case there was some confusion. When you create a VPC, you get a primary classless inter-domain routing CIDR block. There's a big sentence you can use in parties to have people impressed by your knowledge. Not really. It's just one of these dinosaur terms, meaning that it's been around for a long time, and all it's doing is defining a range of addresses that you want to use for a particular VPC and the subnets in that VPC that you create. There's both a primary and a secondary, meaning more addresses, but you have to have a starting point, a primary. It's the main address range, and between 16 and 28, so a /16 has the most addresses, 65,000 and change, /28 has 11. Probably not going to use 11, but then again, maybe you will create a VPC, and you want to ensure that there's only 10 max servers. For security…

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