Bug ID 749608: HTTP Persistence cookies erroneously sent when cookie persistence turned off

Last Modified: Sep 13, 2023

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

Known Affected Versions:
12.1.3,,,,,,,, 12.1.4,, 12.1.5,,,, 12.1.6, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0,,,,,,,,, 13.1.1,,,,, 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,,,

Fixed In:

Opened: Nov 13, 2018

Severity: 3-Major


Traffic may appear to not be load balancing among a pool correctly. Because clients are receiving persistence cookies when they should not be, a client can be routed back to the same pool member for subsequent requests when this is not necessary, instead of being assigned a pool member through load balancing.


The system erroneously sends persistence cookies with responses. Undesired routing might occur, where a client is not load balanced, and instead is always directed back to the same pool member.


This occurs when two conditions are met 1) - The always_send option must be on with HTTP persistence cookies or - Cookies are configured with an expiry 2) Later, persistence is change to 'persist none' (by an iRule, for example).


Turn off the always-send option, and disable the HTTP persistence cookie expiry. If you need the expiry function, use an iRule to re-add it after the cookie has been inserted.

Fix Information


Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips