What should the solutions architect do to meet these requirements?
Create a Network Load Balancer backed by an Auto Scaling group with a UDP listener.
Create a Network Load Balancer backed by a Spot Fleet with instances in a partition placement group.
Create a Network Load Balancer backed by the existing servers in different Availability Zones as the target.
Create a Network Load Balancer backed by an Auto Scaling group with instances in multiple Availability Zones as the target.
Explanations:
While a Network Load Balancer (NLB) can be used, a UDP listener is not suitable for a bastion host, which typically uses SSH (TCP). Additionally, an Auto Scaling group would not be the most efficient way to manage stateful connections like SSH.
Using a Spot Fleet introduces potential interruptions, which is not ideal for a bastion host that requires high availability. Partition placement groups are better for high-performance applications but do not directly address the need for minimal maintenance and resilience.
While backing an NLB with existing servers in different Availability Zones helps distribute traffic, it lacks the automated scaling capabilities of an Auto Scaling group, making maintenance more difficult as it requires manual intervention to add or remove instances.
This option provides high availability by utilizing multiple Availability Zones with an Auto Scaling group, which allows for automatic scaling based on demand. This setup ensures that the bastion host is resilient, can handle failures, and requires minimal maintenance compared to other options.
I chart that the answer is:
Create a Network Load Balancer backed by an Auto Scaling group with instances in multiple Availability Zones as the target.