Secure Access to Database Servers

Answer - B.

The AWS Documentation mentions the following.

A bastion host is a server whose purpose is to provide access to a private network from an external network, such as the Internet.

Because of its exposure to potential attacks, a bastion host must minimize the chances of penetration.

For example, you can use a bastion host to mitigate the risk of allowing SSH connections from an external network to the Linux instances launched in a private subnet of your Amazon Virtual Private Cloud (VPC).

Option A is incorrect since the bastion host needs to be in the public subnet.

Options C and D are incorrect since the NAT instance should not be used as a jump server to the database servers.

For more information on using a bastion host, please refer to the below URL-

https://aws.amazon.com/blogs/security/how-to-record-ssh-sessions-established-through-a-bastion-host/

To enable administrators from your on-premises environment to access the database servers located in a private subnet, you need to provide a secure way to establish the connection between the on-premises environment and the database servers.

Option A: Create a bastion host in the private subnet as the database servers. Ask the IT administrators to log into the database servers via the bastion host.

This is a secure way to access the database servers. A bastion host is a special-purpose instance that acts as a secure gateway between the on-premises environment and the private subnet where the database servers are located. By connecting to the bastion host first, IT administrators can then securely access the database servers via a secure shell (SSH) connection. The bastion host acts as a jump server, providing a secure way to access the private subnet without exposing the database servers to the public Internet.

Option B: Create a bastion host in the public subnet. Ask the IT administrators to log into the database servers via the bastion host.

This option is less secure than option A. By creating a bastion host in the public subnet, you expose the bastion host to the public Internet, which increases the risk of a security breach. Moreover, the bastion host does not provide a secure way to access the database servers located in the private subnet.

Option C: Create a NAT instance in the private subnet as the database servers. Ask the IT administrators to log into the database servers via the NAT Instance.

This option is not secure because a NAT instance is used for outbound Internet traffic from the private subnet to the public Internet. It is not designed to provide a secure way to access resources in the private subnet from the on-premises environment.

Option D: Create a NAT instance in the public subnet as the database servers. Ask the IT administrators to log into the database servers via the NAT Instance.

This option is also not secure because it involves exposing the database servers to the public Internet. A NAT instance is used for outbound Internet traffic from the private subnet to the public Internet. It is not designed to provide a secure way to access resources in the private subnet from the on-premises environment.

In summary, option A is the most secure way to access the database servers located in the private subnet from the on-premises environment. By creating a bastion host in the private subnet, you provide a secure gateway that enables IT administrators to access the database servers via a secure shell (SSH) connection, without exposing the servers to the public Internet.