Bug ID 517510: HTTP monitor might add extra CR/LF pairs to HTTP body when supplied

Last Modified: Oct 06, 2020

Bug Tracker

Affected Product:  See more info
BIG-IP LTM(all modules)

Known Affected Versions:
11.5.1, 11.5.1 HF1, 11.5.1 HF10, 11.5.1 HF11, 11.5.1 HF2, 11.5.1 HF3, 11.5.1 HF4, 11.5.1 HF5, 11.5.1 HF6, 11.5.1 HF7, 11.5.1 HF8, 11.5.1 HF9, 11.5.10, 11.5.2, 11.5.2 HF1, 11.5.3, 11.5.3 HF1, 11.5.3 HF2, 11.6.0, 11.6.0 HF1, 11.6.0 HF2, 11.6.0 HF3, 11.6.0 HF4, 11.6.0 HF5, 11.6.0 HF6, 11.6.0 HF7, 11.6.0 HF8, 11.6.1

Fixed In:
12.0.0, 11.6.1 HF1, 11.5.4

Opened: Apr 10, 2015
Severity: 3-Major
Related AskF5 Article:


When supplying HTTP containing body text to the HTTP monitor, the system might append extra CR/LF pairs to the end.


This may cause malformed POST or PUT messages.


HTTP monitor with text specifying HTTP body text.


Limited work-around entails providing an alternative HTTP health check that does not require PUTting or POSTing a body.

Fix Information

The HTTP monitor has been fixed to avoid adding additional CR/LF pairs, except for the case where only headers are supplied and there are insufficient CR/LF supplied to terminate the headers.

Behavior Change