Bug ID 1106081: Server responds with 400 Bad request to HTTP monitor traffic

Last Modified: Jun 28, 2025

Affected Product(s):
BIG-IP LTM(all modules)

Known Affected Versions:
16.1.0, 16.1.1, 16.1.2, 16.1.2.1, 16.1.2.2, 16.1.3, 16.1.3.1, 16.1.3.2, 16.1.3.3, 16.1.3.4, 16.1.3.5, 16.1.4, 16.1.4.1, 16.1.4.2, 16.1.4.3, 16.1.5, 16.1.5.1, 16.1.5.2, 16.1.6

Opened: May 12, 2022

Severity: 3-Major

Symptoms

Pool members return 400 Bad Request to HTTP monitor traffic, and checking the pool member manually via cURL or Postman indicates that the server is responding with 200 OK.

Impact

The pool member responds with 400 Bad request and is marked down.

Conditions

-- Pool member with an HTTP monitor -- The send string sends a POST request that contains a JSON payload and NTLM auth

Workaround

Write an EAV external monitor to monitor the node.

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips