BugZero | F5 BugID 740963 - VIP-targeting-VIP traffic can cause TCP retransmit...

F5 - Defect ID: 740963

VIP-targeting-VIP traffic can cause TCP retransmit bursts resulting in tmm restart

F5 - Defect ID: 740963

VIP-targeting-VIP traffic can cause TCP retransmit bursts resulting in tmm restart

Last updated on July 18th, 2026

BugZero Risk Score
8.6 High

Overall: 8.6

Severity: 9.1

Community: 4.2

Lifecycle: 8.3

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Bug Details

Priority: 2-Critical
Status: Verified
Impact Category: Local Traffic Manager

Description

Symptoms

VIP-on-VIP traffic might cause TCP retransmit bursts, which in certain situations can cause tmm to restart.

Impact

Temporary memory consumption and potential for tmm to restart. Traffic disrupted while tmm restarts.

Conditions

- Virtual server handling TCP traffic. - iRule using the 'virtual' command.

Workaround

None.

Fix Information

TCP retransmit bursts are now handled gracefully.

Change history

Links

Original Vendor Announcement

Relevant Products

Click on a version to see all relevant bugs

Affected versions: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, 12.1.4, 12.1.4.1, 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

Fixed versions: 14.1.0, 14.0.0.5, 13.1.1.4, 12.1.5

Relevant Products

Click on a version to see all relevant bugs

Fixed versions: 14.1.0, 14.0.0.5, 13.1.1.4, 12.1.5

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F5 - Defect ID: 740963

VIP-targeting-VIP traffic can cause TCP retransmit bursts resulting in tmm restart

F5 - Defect ID: 740963

VIP-targeting-VIP traffic can cause TCP retransmit bursts resulting in tmm restart

Last updated on July 18th, 2026

BugZero Risk Score8.6 High

Bug Details

Symptoms

Impact

Conditions

Workaround

Fix Information

Links

Top F5 Defects

Ready to prevent the next vendor outage?

F5 - Defect ID: 740963

VIP-targeting-VIP traffic can cause TCP retransmit bursts resulting in tmm restart

F5 - Defect ID: 740963

VIP-targeting-VIP traffic can cause TCP retransmit bursts resulting in tmm restart

Last updated on July 18th, 2026

BugZero Risk Score8.6 High

Bug Details

Symptoms

Impact

Conditions

Workaround

Fix Information

Links

Top F5 Defects

Ready to prevent the next vendor outage?

BugZero Risk Score
8.6 High

BugZero Risk Score
8.6 High