Bug ID 737252: TCL error: ERR_NOT_SUPPORTED when iRule code executed after HTTP::respond or other commands

Last Modified: Nov 07, 2022

Bug Tracker

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

Known Affected Versions:
14.1.0,,,,,, 14.1.2,,,,,,,,, 14.1.3,, 14.1.4,,,,,,, 14.1.5,,, 15.0.0, 15.0.1,,,,, 15.1.0,,,,,, 15.1.1, 15.1.2,, 15.1.3,, 15.1.4,, 15.1.5,, 15.1.6,, 15.1.7, 15.1.8, 16.0.0,, 16.0.1,,, 16.1.0, 16.1.1, 16.1.2,,, 16.1.3,,, 17.0.0,

Opened: Jul 17, 2018
Severity: 2-Critical
Related AskF5 Article:


Connections are dropped, and you see the following errors in /var/log/ltm: 01220001:3: TCL error: /Common/<iRule_name> <HTTP_REQUEST> - ERR_NOT_SUPPORTED (line 1) invoked from within "HTTP::host".


When this error is encountered, an error is logged and the connection is dropped.


iRule with any of the following commands: -- HTTP::respond -- HTTP::redirect -- HTTP::retry iRule contains code (such as logging code) following the command, and the code uses something from HTTP, for example: log local0.debug "[HTTP::uri]"


Alter your iRule code to not contain any iRule commands following HTTP::respond, HTTP::redirect, or HTTP::retry. You can use HTTP::has_responded to detect whether HTTP has already responded.

Fix Information


Behavior Change

HTTP iRule commands that inspect HTTP state after the commands HTTP::respond, HTTP::redirect, and HTTP::retry now return errors instead of returning corrupt data. It may be useful to check HTTP::has_responded to detect whether or not HTTP state is unavailable.