Bug ID 1001041: Reset cause 'Illegal argument'

Last Modified: Sep 13, 2023

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

Known Affected Versions:
13.1.3,,,,,,, 13.1.4,, 13.1.5,, 14.0.0,,,,,, 14.0.1,, 14.1.0,,,,,, 14.1.2,,,,,,,,, 14.1.3,, 14.1.4,,,, 15.0.0, 15.0.1,,,,, 15.1.0,,,,,, 15.1.1, 15.1.2,, 15.1.3,, 16.0.0,, 16.0.1,,

Fixed In:
16.1.0, 15.1.4,

Opened: Mar 10, 2021

Severity: 3-Major


Client connections get aborted usually after the full transfer of the HTTP Post request. If logging of reset reason is enabled using: tmsh modify sys db tm.rstcause.log value enable LTM logs report the reset reason as 'Illegal Argument'.


Clients cannot post large files to backend servers with APM PingAccess support.


When using the APM PingAccess feature, any HTTP transaction that takes a long time to complete can result in this issue. This issue can be triggered if there is a large POST request or if the backend server is slow in responding to the requests.



Fix Information

The timeout is now properly handled for large post requests, so that no reset occurs.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips