Exam ANS-C00 topic 1 question 87 discussion

Each desktop requires two NIC - primary network interface (eth1) and management network interface (eth0). Requires two subnets - both subnet can be private with NATGW. This means 1 desktop requires 2 x IPs in two subnets; 1000 desktops requires 2 x 1000 IPs in two subnets. D. /23 gives us 512 IPs - not an option for 1000 desktop C. one /22 - WorkSpaces requires 2 x VPC subnets B. two /21 within a /20 - this is a good one to host 1000 primary interface eth1 + 1000 management IPs eth0 A. one /21 - WorkSpaces requires 2 x VPC subnets

B is the right Answer

Workspaces require two subnets in two different AZ, so A and C are out. Option D is too small for future expansion: /23 per subnet leaves us with 1012 IPs for Workspaces (2x (512 - 5 AWS reserved IP - 1 IP for directory service) ) Thus Option B is the correct answer

Workspaces needs to subnets to the options with 1 subnets are rules out https://docs.aws.amazon.com/workspaces/latest/adminguide/amazon-workspaces-vpc.html

Workspaces require two subnets in two AZs, so only B and D can be considered. /23 is too small. Correct answer is B then.

I would go with A. https://docs.aws.amazon.com/workspaces/latest/adminguide/amazon-workspaces.html. Each WorkSpace has two elastic network interfaces associated with it: a network interface for management and streaming (eth0) and a primary network interface (eth1). The primary network interface has an IP address *provided by your VPC*, from the same subnets used by the directory. You don't provide the 2nd one. AWS takes care of that for you.

Answer B: we need 2,000 IPs for 1,000 WorkSpace desktops and must have two subnets. Each WorkSpace has the following network interfaces: The primary network interface (eth1) provides connectivity to the resources within your VPC and on the internet, and is used to join the WorkSpace to the directory. The management network interface (eth0) is connected to a secure Amazon WorkSpaces management network. It is used for interactive streaming of the WorkSpace desktop to Amazon WorkSpaces clients, and to allow Amazon WorkSpaces to manage the WorkSpace. https://docs.aws.amazon.com/workspaces/latest/adminguide/workspaces-port-requirements.html

B is correct answer. 2 subnets in different AZ is the requirement for setting up directory constructs (HA purpose). 2 IP addresses will be consumed the directory. But the workspaces we create will be launched in either of these 2 subnets and consume only 1 IP address. With /23 subnets, we will have a total of 1012 usable IP and scaling will be an issue here.

Answer should be A I think. Workspace requires two subnets, one is in your VPC, the other is in the AWS managed VPC that is not visible to us. So you don't need to allocate subnet for both. Client -> Workspace (eth0 - AWS managed VPC) with login/authentication, from the Workspace desktop, all traffic to your VPC or other resource will use eth1 which is in your VPC. As per link below:https://d1.awsstatic.com/whitepapers/workspaces/Best_Practices_for_Deploying_Amazon_WorkSpaces.pdf

B is the only suitable option. Believe me!

I lean to B as the question asking for FUTURE Growth as well...

I believe the correct answer is D.

Definitely not A or C because you have to have at least 2 subnets in different AZ's to launch WorkSpaces in. B works because you will immediately have provision of 2x /21 subnets with 2,048 addresses in each, but that's all /20 addresses consumed so no more growth other than for WorkSpaces. D is the better answer because this immediately provides 1,024 IP addresses for WorkSpaces (minus the usual) so works from day 1 with additional CIDR space available for allocation to WorkSpaces and/or other services within the VPC as it grows. That said, I believe the correct answer is D.

The following link provides some helpful info: https://docs.aws.amazon.com/workspaces/latest/adminguide/amazon-workspaces.html

The answer is B. A couple of key factors to consider: 1) WorkSpace requires a minimum 2 subnets; 2) Each WorkSpace has two elastic network interfaces associated with it: a network interface for management and streaming (eth0) and a primary network interface (eth1). 3) The architecture must allow for future expansion. A /20 CIDR and two /21 subnets provides 4096 IP addresses minus some AWS reserved IP addresses (5 per subnet), thus B is the answer.

Workspaces requires 2 subnets to deploy, these are mandatory fields you must complete. D give you little room to expand. As you cannot add additional subnets apart from 2, this is not the right choice. B. Yes. Give room for expansion + 2 subnets. More accurate answer.

Ans is B