amazon web services - AWS: how to connect together 2 public subnets

Question

There's plenty of advice online on how to:

• connect public subnet to private
• connect 2 separate VPCs together

But I can't find anything on how to connect 2 public subnets within the same VPC. Currently I have them connected to the same Internet Gateway, but the resources in one don't talk to the other.

What's the right approach to solve this?

question from:https://stackoverflow.com/questions/65924184/aws-how-to-connect-together-2-public-subnets

Answer 1

All subnets (regardless of whether they are Public or Private) within the same Amazon VPC can communicate with each other by default.

Communication should be made via the private IP address of the resources, to ensure that the traffic stays within the VPC.

If this is not working, check:

• Security Groups on the resources, to ensure they are permitting access (Note: Merely putting resources in the 'same' Security Group does not mean that they can communicate with each other)
• Network ACLs should be left at their default "Allow All" setting. Only change NACLs if there is a very good reason to do so (eg creating a DMZ).