AWS Certified SysOps Administrator – Associate (legacy) — Question 733

A SysOps administrator needs to register targets for a Network Load Balancer (NLB) using IP addresses.
Which prerequisite should the SysOps administrator validate to perform this task?

Answer options

• A. Ensure the NLB listener security policy is set to ELBSecurityPolicy-TLS-1-2-Ext-2018-06, ELBSecurityPolicy-FS-1-2-Res-2019-08, or ELBSecurityPolicy-TLS- 1-0-2015-04.
• B. Ensure the health check setting on the NLB for the Matcher configuration is between 200 and 399.
• C. Ensure the targets are within any of these CIDR blocks: 10.0.0.0/8 (RFC 1918), 100.64.0.0/10 (RFC 6598), 172.16.0.0/12 (RFC 1918), or 192.168.0.0/16 (RFC 1918).
• D. Ensure the NLB is exposed as an endpoint service before registering the targets using IP addresses.

Correct answer: D

Explanation

Exposing the Network Load Balancer (NLB) as a PrivateLink VPC endpoint service is a prerequisite when registering certain IP-based targets, especially across VPC boundaries. Security policies (Option A) and health check matcher codes (Option B) are configuration details that do not act as prerequisites for IP target registration. While CIDR ranges (Option C) specify valid IP addresses, exposing the NLB as an endpoint service is the required administrative step to enable this connectivity.