A company wants to implement their website in a virtual private cloud (VPC). The web tier will use an AutoScaling group across multiple Availability Zones (AZs). The database will use Multi-AZ RDS MySQL and should
not be publicly accessible. What is the minimum number of subnets that need to be configured in the VPC?
A.
1
B.
2
C.
3
D.
4
Explanation:
Since multi-AZ RDS needs 2 private subnets to provide high availability and 2 public subnets are needed for
ELB(web-tier) application.
D. 4 (2 public subnets for web instances in multiple AZs and 2 private subnets for RDS Multi-AZ)
The database will use Multi-AZ RDS MySQL and should
not be publicly accessible.
=>2
[not be publicly accessible] is possible by setting RDS option(Publicly Accessible : No).
So, I think that (B. 2) is correct…
You will need 4. 2 public, 2 private spanning 2 AZ’s.
Web App needs 2 subnets (2AZ)
DB needs 2 subnets (2AZ, but note that this can be the sane AZ`s used on the subnets from the Web App)
So we have a minimum of:
4 Subnets and 2 AZ’s