Several lightly used AZ-local NAT Gateways in a parks-and-recreation VPC drive fixed hourly charges. Some architects want one shared NAT to save money; others worry about losing AZ isolation for egress during an AZ event. Which recommendation best balances cost and reliability?
Select an answer to reveal the explanation.
Short Explanation
One NAT is cheaper; one NAT is also a single door when an AZ coughs. Consolidate the sleepy ones where isolation isn’t required, keep per-AZ NAT where it is, and write down the tradeoff. Public IPs on private instances are not the answer.
Full Explanation
NAT Gateway cost optimization must weigh hourly charges against AZ failure domains. Consolidating underused NATs can save money when workloads tolerate shared egress, but production tiers that need AZ-independent outbound paths should retain per-AZ NAT. Blind single-NAT consolidation, public IPs on private instances, or IGWs on private subnets ignore that reliability tradeoff.