VPC sizing and structure

Question 1

What key points should be considered for VPCs?

Answer 1

1. Size - because this limits the use and how many services will be used –> CIDR range
2. Are there any networks that we can’t use?
3. Consider not overlapping the CIDR range with other cloud environments - VPCs, cloud, on-premises, partners, vendors…
4. Try to predict future uses
5. Try to predict the VPC structure - tiers and resilience (availability)
6. VPC min /28 (16 IP)
7. VPC max /16 (65456 IPs)
8. Avoid common range 10.0 or 10.1, include up to 10.10

Question 2

What defines how big the VPC will be?

Answer 2

The VPC CIDR range.

Question 3

Why is it a good practice trying not to overlap IP ranges even within private networks?

Answer 3

Because it will make more difficult the communication between networks.

Question 4

What is the minimum size for a VPC?

Answer 4

/28 (16 IP)

Question 5

What is the maximum size for a VPC?

Answer 5

/16 (65456 IPs)

Question 6

What is the main recommendation when designing a VPC?

Answer 6

Try to split each subnet into tiers (web, application, db, spare).