Last Modified: Jul 18, 2026
Affected Product(s):
BIG-IP GTM, LTM
Known Affected Versions:
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
Opened: Sep 22, 2015 Severity: 3-Major
A TCL error, such as referencing an undefined variable, in a DNS_RESPONSE iRule event can cause a tmm crash. This can occur on a UDP listener with a DNS profile without datagram load balancing enabled. A DNS_REQUEST event, with any content, on the same listener is also required.
Traffic disrupted while tmm restarts.
All of the following: UDP listener with DNS profile without datagram load balancing. A TCL error, such as referencing an undefined variable, in a DNS_RESPONSE iRule event. A DNS_REQUEST iRule event with any content.
Either add datagram load balancing to the listener or correct the TCL errors that lead to the problem.
None