Last Modified: Oct 15, 2025
Affected Product(s):
BIG-IP TMOS
Known Affected Versions:
17.1.0, 17.1.0.1, 17.1.0.2, 17.1.0.3, 17.1.1, 17.1.1.1, 17.1.1.2, 17.1.1.3, 17.1.1.4, 17.1.2, 17.1.2.1, 17.1.2.2, 17.1.3
Opened: Jul 02, 2025 Severity: 3-Major
Disabling HT-Split on VELOS and some rSeries appliances is not supported. The SDAG disaggregation (DAG) algorithm used on VELOS and some rSeries appliances does not function properly if HT-Split (splitplanes) is disabled. The sdag expects splitplanes to be in affect, where the number of TMMs is half the amount of CPU cores provided to the tenant. Any traffic using the TMM threads that are not expected to exist will fail.
Intermittent traffic issues.
- r5000-, r10000, or r12000-series appliance or VELOS chassis - The db variable scheduler.splitplanes.ltm is set to "false" This can happen when migrating a configuration (i.e. via UCS archive) from another platform, if the source device had HT-Split disabled.
Re-enable HT-Split: tmsh modify sys db scheduler.splitplanes.ltm value true tmsh modify sys db scheduler.splitplanes.ltm reset-to-default Reboot the tenant on rSeries or all tenant slots on VELOS.
None