By using AWS re:Post, you agree to the Terms of Use
/VPC/CIDR IPv4 issue/

VPC/CIDR IPv4 issue

0

Hello, Good day. Just started learning how to write IAAC on Cloud Formation using my text editor and I noticed something I don't understand.

Scenario 1 : If i create a VPC with an IPv4 CIDR (10.0.1.0/16) it rejects on the AWS console as invalid.

Scenario 2 : But if i run it as IAAC (Cloud formation) on a connected text editor, it corrects the mistake and works but the error remains in the CFN template

why?

I have screenshots incase this is needed.

Thank you

1 Answers
3

This is because CloudFormation corrects the VPC CIDR to its canonical form. See https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ec2-vpc.html

CidrBlock The IPv4 network range for the VPC, in CIDR notation. For example, 10.0.0.0/16. We modify the specified CIDR block to its canonical form; for example, if you specify 100.68.0.18/18, we modify it to 100.68.0.0/18.

answered 25 days ago
EXPERT
reviewed 25 days ago
  • This explains it quite well. Thank you very much.

You are not logged in. Log in to post an answer.

A good answer clearly answers the question and provides constructive feedback and encourages professional growth in the question asker.

Guidelines for Answering Questions