BugZero | F5 BugID 674591 - Packets with payload smaller than MSS are being ma...

F5 - Defect ID: 674591

Packets with payload smaller than MSS are being marked to be TSOed

F5 - Defect ID: 674591

Packets with payload smaller than MSS are being marked to be TSOed

Last updated on July 18th, 2026

BugZero Risk Score
6.7 Medium

Overall: 6.7

Severity: 7.3

Community: 4.2

Lifecycle: 7.0

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Bug Details

Priority: 3-Major
Status: Verified
Impact Category: Local Traffic Manager

Description

Symptoms

Packets with length less than the specified MSS are sent as TSO packets, and the Broadcom NIC drops those to degrade performance.

Impact

TCP Packets are dropped.

Conditions

When TM.TcpSegmentationOffload is enabled, Packets with length less than MSS are sent as TSO packets.

Workaround

Disable TSO option by setting the following SYS DB variable to disable: TM.TcpSegmentationOffload.

Fix Information

Packets less than MSS are not sent as TSO packets, so there is no performance degradation.

Change history

Links

Original Vendor Announcement

Relevant Products

Click on a version to see all relevant bugs

Affected versions:11.5.4, 11.5.4 hf1, 11.5.4 hf2, 11.5.4 hf3, 11.5.4 hf4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10, 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, 11.6.1, 11.6.1 hf1, 11.6.1 hf2, 11.6.2, 11.6.2 hf1, 11.6.3, 11.6.3.1, 11.6.3.2, 11.6.3.3, 11.6.3.4, 11.6.4, 11.6.5, 11.6.5.1, 12.0.0, 12.0.0 hf1, 12.0.0 hf2, 12.0.0 hf3, 12.0.0 hf4, 12.1.0, 12.1.0 hf1, 12.1.0 hf2, 12.1.1, 12.1.1 hf1, 12.1.1 hf2, 12.1.2, 12.1.2 hf1, 12.1.2 hf2, 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, 13.0.0, 13.0.0 hf1, 13.0.0 hf2, 13.0.0 hf3, 13.0.1, 13.1.0, 13.1.0.1, 13.1.0.2, 13.1.0.3, 13.1.0.4, 13.1.0.5, 13.1.0.6, 13.1.0.7, 13.1.0.8, 13.1.1, 13.1.1.2, 13.1.1.3, 14.0.0, 14.0.0.1, 14.0.0.2, 14.0.0.3, 14.0.0.4, 14.0.0.5, 14.0.1, 14.0.1.1

Fixed versions: 14.1.0, 13.1.1.4, 12.1.4, 11.6.5.2

Relevant Products

Click on a version to see all relevant bugs

Fixed versions: 14.1.0, 13.1.1.4, 12.1.4, 11.6.5.2

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F5 - Defect ID: 674591

Packets with payload smaller than MSS are being marked to be TSOed

F5 - Defect ID: 674591

Packets with payload smaller than MSS are being marked to be TSOed

Last updated on July 18th, 2026

BugZero Risk Score6.7 Medium

Bug Details

Symptoms

Impact

Conditions

Workaround

Fix Information

Links

Top F5 Defects

Ready to prevent the next vendor outage?

F5 - Defect ID: 674591

Packets with payload smaller than MSS are being marked to be TSOed

F5 - Defect ID: 674591

Packets with payload smaller than MSS are being marked to be TSOed

Last updated on July 18th, 2026

BugZero Risk Score6.7 Medium

Bug Details

Symptoms

Impact

Conditions

Workaround

Fix Information

Links

Top F5 Defects

Ready to prevent the next vendor outage?

BugZero Risk Score
6.7 Medium

BugZero Risk Score
6.7 Medium