A team's AWS account already has five Elastic IP addresses allocated in the us-east-1 Region, the AWS default quota for that Region. They attempt to allocate a sixth Elastic IP address for a new NAT gateway in the same Region without taking any other action first. What happens?
- It succeeds automatically, because Elastic IP address quotas apply per Availability Zone, not per Region, and this new address is being allocated for a different purpose (a NAT gateway) than the existing five
- It fails, because five Elastic IP addresses per Region is the default quota for an AWS account, and the account must request a quota increase through the Service Quotas console before allocating more
- It succeeds automatically, because Elastic IP address quotas apply only to addresses associated with running EC2 instances, and NAT gateway Elastic IP addresses are exempt from the quota
- It fails permanently, because five Elastic IP addresses per Region is a hard limit that cannot be raised even with a quota increase request
Why B? And why not the others?
Correct answer: B. It fails, because five Elastic IP addresses per Region is the default quota for an AWS account, and the account must request a quota increase through the Service Quotas console before allocating more
By default, every AWS account has a quota of five Elastic IP addresses per Region, because public IPv4 addresses are a scarce shared resource; that quota is enforced at the account-and-Region level regardless of what the address will be used for, so the sixth allocation attempt is rejected until the account requests and receives a quota increase from the Service Quotas console. The per-Availability-Zone option is wrong because Elastic IP quotas are tracked per Region, not per Availability Zone, and the intended purpose of the address (NAT gateway versus EC2 instance) doesn't change which pool it draws from. The 'exempt for NAT gateways' option is wrong for the same reason: a NAT gateway's Elastic IP address counts against the exact same account-and-Region quota as any other Elastic IP address. The 'hard limit' option is wrong because this quota, unlike some AWS limits, is explicitly adjustable — the account can request and be granted a higher quota rather than being permanently capped at five.
Source: AWS documentation and AWS re:Post: default Elastic IP address quota is 5 per Region for EC2-VPC, adjustable via a Service Quotas increase request