A node is a member of various pools and hosts different web applications. If a web application is unavailable, the BIG-IP appliance needs to mark the pool member down for that application pool. What should a BIG-IP Administrator deploy at the pool level to accomplish this? (Choose one answer)

A. A combination of ICMP + TCP monitor
B. A TCP monitor with a custom interval/timeout
C. A UDP monitor with a custom interval/timeout
D. An HTTP monitor with custom send/receive strings

Correct Answer: D

Brave-Dump Clients Votes

D 100%

Comments

Anonymous User 2026-01-17 20:42:50

Selected Answers: D

To mark a pool member down specifically for an unavailable web application, the BIG-IP Administrator should deploy an HTTP monitor with custom send/receive strings (D) to check the specific application's response, ensuring it probes the correct URI and verifies expected content, rather than just the port (TCP) or general network reachability (ICMP).
Here's why:
Web Applications need Application-Level Checks: A simple TCP monitor checks if the port is open, but not if the application itself is healthy and serving requests correctly. An HTTP monitor actively sends an HTTP request (like a GET) to a specific URL.
Customization is Key: By configuring custom send/receive strings, the administrator can define a precise request (e.g., GET /healthcheck.html) and expect specific content (e.g., "OK", "200 OK").
Addressing the Scenario: If only one web application on a shared node goes down, but the node itself (and other apps) are fine, an HTTP monitor targeting that app's specific endpoint will correctly mark the member down for that specific pool, isolating the issue without affecting other services.
The other options are less precise:
ICMP + TCP: Checks basic network connectivity (ICMP) and port status (TCP), not application logic.
TCP Monitor: Only confirms the port is open, not that the web service is functioning.
UDP Monitor: For connectionless services, not standard web applications.