Last Modified: Aug 19, 2026
Affected Product(s):
BIG-IP TMOS
Known Affected Versions:
11.5.4, 11.5.4 hf1, 11.5.4 hf2, 11.5.4 hf3, 11.5.4 hf4, 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, 11.6.1 hf1, 11.6.1 hf2, 11.6.2, 11.6.2 hf1, 12.0.0, 12.0.0 hf1, 12.0.0 hf2, 12.0.0 hf3, 12.0.0 hf4, 12.1.0, 12.1.0 hf1, 12.1.0 hf2, 12.1.1, 12.1.1 hf1, 12.1.1 hf2, 12.1.2, 12.1.2 hf1, 12.1.2 hf2, 13.0.0, 13.0.0 hf1, 13.0.0 hf2, 13.0.0 hf3, 13.0.1
Fixed In:
13.1.0, 12.1.3, 11.6.3, 11.5.5
Opened: Apr 21, 2017 Severity: 2-Critical Related Article:
K10589537
The dynamic pool member load-balancing modes require a precision measurement of active connection counts and/or rates. Rare, intermittent system instability has been observed in dynamic pool member selection when a new connection arrives. TMM may restart, leaving a core file.
TMM restarts and leaves a core file. Traffic disrupted while tmm restarts.
LTM pool configured to use a dynamic load-balancing mode ('ltm pool NAME load-balancing-mode MODE' where MODE is one of the dynamic load-balancing modes, such as dynamic-ratio-member, least-connections-node, predictive-node, etc.). The dynamic modes use the session database to share data among all TMM instances, and under extremely rare conditions, the session database may become unreliable.
None.
The dynamic load-balancing modes are now more tolerant of errors from the underlying session database.