Implementation Steps for Setting Up a Management Network in an AWS VPC

Answer - A.

The AWS Documentation mentions the following to support this.

Attaching multiple network interfaces to an instance is useful when you want to:

· Create a management network.

· Use network and security appliances in your VPC.· Create dual-homed instances with workloads/roles on distinct subnets.

· Create a low-budget, high-availability solution.

All other options automatically are invalid since the primary implementation step is to create multiple ENI's.

For more information on Elastic Network Interfaces, please refer to the below URL.

https://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/VPC_ElasticNetworkInterfaces.html

Creating a Management Network.

You can create a management network using network interfaces.

In this scenario, the primary network interface (eth0) on the instance handles public traffic, and the secondary network interface (eth1) handles backend management traffic.

It is connected to a separate subnet in your VPC that has more restrictive access controls.

The public interface, which may or may not be behind a load balancer, has an associated security group that allows access to the server from the internet (for example, allow TCP port 80 and 443 from 0.0.0.0/0, or from the load balancer) while the private facing interface has an associated security group allowing SSH access only from an allowed range of IP addresses either within the VPC or from the internet, a private subnet within the VPC or a virtual private gateway.

https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-eni.html#AvailableIpPerENI

The requirement to set up a management network inside of a VPC involves creating a separate network for managing the EC2 instances. This network will be used for administrative purposes, such as remote access to the instances, monitoring, and backup.

To implement this, one of the steps would be to attach multiple Elastic Network Interfaces (ENIs) to an instance. An ENI is a virtual network interface that can be attached to an instance to enable it to communicate with other resources in the VPC. By attaching multiple ENIs to an instance, it is possible to create multiple network interfaces for different purposes.

Option A is the correct answer because it is the only option that suggests attaching multiple ENIs to an instance.

Option B, attaching multiple public IP addresses to an existing ENI, is not a recommended approach because public IP addresses are scarce and should only be used when necessary.

Option C, attaching multiple Elastic IP addresses to an existing ENI, is also not the best approach because an Elastic IP address is associated with a single ENI, and it is not possible to attach multiple Elastic IP addresses to a single ENI.

Option D, attaching multiple private IP addresses to an existing ENI, is possible, but it does not provide a separate network for managing the EC2 instances. Instead, it only adds multiple IP addresses to a single network interface.

Therefore, the correct option is A, which involves attaching multiple ENIs to an instance to create a separate management network inside of the VPC.