Bug ID 743253: TSO in software re-segments L3 fragments.

Last Modified: Sep 13, 2023

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

Known Affected Versions:
11.5.0, 11.5.1, 11.5.2, 11.5.3, 11.5.4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10, 12.1.0, 12.1.1, 12.1.2, 12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 12.1.3.6, 12.1.3.7, 12.1.4, 12.1.4.1, 12.1.5, 12.1.5.1, 12.1.5.2, 12.1.5.3, 12.1.6, 15.0.0, 15.0.1, 15.0.1.1, 15.0.1.2, 15.0.1.3, 15.0.1.4

Fixed In:
16.1.0, 16.0.1.2, 15.1.3, 14.1.4

Opened: Sep 07, 2018

Severity: 4-Minor

Symptoms

FastL4 does not re-assemble fragments by default, but on a system with software-enabled TSO (sys db tm.tcpsegmentationoffload value disable), those fragments are erroneously re-segmented.

Impact

Already-fragmented traffic is fragmented again.

Conditions

The behavior is encountered on BIG-IP Virtual Edition when setting sys db tm.tcpsegmentationoffload value disable, but does not cause a tmm core on Virtual Edition.

Workaround

None

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips