Bug ID 557680: Fast successive MTU changes to IPsec tunnel interface crashes TMM

Last Modified: Oct 06, 2020

Bug Tracker

Affected Product:  See more info
BIG-IP LTM(all modules)

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, 12.1.0, 12.1.0 HF1, 12.1.0 HF2, 12.1.1, 12.1.1 HF1, 12.1.1 HF2

Fixed In:
13.0.0, 12.1.2, 11.6.1

Opened: Nov 11, 2015
Severity: 2-Critical
Related AskF5 Article:


Changing IPsec tunnel interface MTU attribute repeatedly in quick succession, TMM cores. This can occur whether or not traffic has flowed through the tunnel.


Traffic disrupted while tmm restarts.


The issue occurs when the IPsec tunnel interface attributes has its configuration modified quickly and repeatedly.


Change IPsec tunnel interface attributes at a rate of speed that allows each configuration modification to complete.

Fix Information

TMM no longer cores if users quickly and repeatedly change interface attributes (for example, the MTU interface attribute).

Behavior Change