
AWS Certified Advanced Networking – Specialty (ANS-C01) Certification Guide
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As mentioned in the VPC Basics section, route tables are utilized to direct traffic in and potentially out of a VPC using the VPC router. If you are familiar with the concept of virtual routing and forwarding (VRF) instances, route tables function in a comparable way within the VPC router. Refer to the following logic.
It is important to remember that the VPC router essentially has an interface within every single subnet that uses the IP address of the network address + 1. Also, each one of these subnets must be associated with a route table. You can visualize it as if all of the subnets associated with the same route table belong to the same VRF instance, that is, they all share the same routing rules when traffic is sent to the default gateway, which is commonly the VPC router.
However, there is one caveat with this analogy. Associating subnets with separate route tables does not inherently imply any segmentation inside the VPC. Segmentation is commonly addressed...