Bug ID 920265: TMM may crash if a virtual server undergoes a series of specific configuration changes involving the transparent-nexthop option.

Last Modified: Jul 12, 2023

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

Known Affected Versions:
13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0,,,,,,,,, 13.1.1,,,,, 13.1.3,,,,,,, 14.0.0,,,,,, 14.0.1,

Fixed In:

Opened: Jun 23, 2020

Severity: 2-Critical


TMM crashes and produces a core dump.


Traffic is impacted while TMM restarts.


This issue occurs when: - You initially enable the transparent-nexthop setting on a virtual server. - You then disable the option. - You then disable auto-lasthop for the virtual server. - The virtual server receives traffic.


There is no workaround that you can instantiate to prevent this issue. However, if you are aware that you have already performed the necessary configuration changes to cause this issue to occur, and TMM has not crashed yet, you can delete the virtual server and recreate it (with the intended/final configuration) to prevent the crash.

Fix Information

TMM no longer crashes after modifying a virtual server as described under Conditions.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips