Last Modified: Aug 19, 2026
Affected Product(s):
BIG-IP All
Known Affected Versions:
11.5.1, 11.5.1 hf1, 11.5.1 hf2, 11.5.1 hf3, 11.5.1 hf4, 11.5.1 hf5, 11.5.1 hf6, 11.5.1 hf7, 11.5.1 hf8, 11.5.1 hf9, 11.5.1 hf10, 11.5.1 hf11, 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, 11.6.3, 11.6.3.1, 11.6.3.2, 11.6.3.3, 11.6.3.4, 11.6.4, 11.6.5, 11.6.5.1, 11.6.5.2, 11.6.5.3
Fixed In:
12.0.0, 11.5.2
Opened: Aug 15, 2014 Severity: 3-Major Related Article:
K16171
HTTP caching configured in a Web Acceleration profile may dispatch internal messages out-of-order, leading to assert
Due to this rarely occurring race condition, a tmm_panic occurs ('valid pcb') when a connection is being closed and the ramcache feature is able fulfill an incoming request. Standby unit becomes temporarily unavailable.
Assert may occur when the following conditions are met: - Virtual server has HTTP caching configured in a Web Acceleration profile. - Virtual server has mirroring enabled. - Device is in standby mode. - Active unit is unable to fulfill incoming HTTP request (ramcache entry is invalid / no pool members). - Standby unit is able to fulfill mirrored request (ramcache entry is valid).
Do not use connection mirroring when HTTP caching is configured in a Web Acceleration.
HTTP caching configured in a Web Acceleration profile no longer dispatches internal messages out-of-order, leading to assert.