Bug ID 935177: IPsec: Changing MTU or PMTU settings on interface mode tunnel cores tmm

Last Modified: Feb 07, 2024

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

Known Affected Versions:
15.1.0,,,,,, 15.1.1, 15.1.2,, 15.1.3,, 15.1.4,, 15.1.5,, 15.1.6, 16.0.0,, 16.0.1,,, 16.1.0, 16.1.1, 16.1.2,

Fixed In:

Opened: Aug 11, 2020

Severity: 2-Critical


TMM crashes when the maximum transmission unit (MTU) or 'Use PMTU' setting is changed while passing IPsec traffic.


Traffic disrupted while tmm restarts.


-- IPsec tunnel configured and passing traffic. -- The MTU or 'Use PMTU' setting for the IPsec tunnel (in interface mode) is changed.


Do not change MTU or PMTU settings for the tunnel while it is passing traffic. The settings can be changed while passing traffic, but TMM may crash very soon after the change. If the settings are changed and TMM does not crash soon after, then it will not spontaneously crash at some later point.

Fix Information


Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips