Bug ID 691498: Connection failure during iRule DNS lookup can crash TMM

Last Modified: Oct 16, 2023

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

Known Affected Versions:
12.1.2, 12.1.3,, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0,,,

Fixed In:

Opened: Oct 30, 2017

Severity: 2-Critical


The TMM crashes in the DNS response cache periodic sweep.


The TMM cores and automatically restarts, Traffic disrupted while tmm restarts.


The DNS resolver connection fails after a successful lookup response is cached. This has been reproduced with a failure due to a lost route. Other failures such as down ports do not cause a crash.


No known workaround.

Fix Information

The reference counting of the resolver connection was fixed.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips