Managing a Network ACL

An AWS Network Access Control List (NACL) works as a firewall at the VPC level for controlling incoming and outgoing requests from one or more subnets associated with that VPC. It is used in conjunction with the Security Group (SG) in controlling traffic to the AWS. When we create a VPC, a default NACL is created that is open to every IP and port. The subnet is associated with the default NACL created during its creation. We can create a custom NACL and associate it with a subnet, thus replacing the default NACL.