Bug ID 819321: DoS stats table shows drops count on tcp-half-open global vector for packets dropped by ltm syn cookie

Last Modified: Jul 12, 2023

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

Known Affected Versions:
14.1.0, 14.1.0.1, 14.1.0.2, 14.1.0.3, 14.1.0.5, 14.1.0.6, 14.1.2, 14.1.2.1, 14.1.2.2, 14.1.2.3, 14.1.2.4, 14.1.2.5, 14.1.2.6, 14.1.2.7, 14.1.2.8, 14.1.3, 14.1.3.1, 15.0.0, 15.0.1, 15.0.1.1, 15.0.1.2, 15.0.1.3, 15.0.1.4

Fixed In:
15.1.0, 14.1.4

Opened: Aug 30, 2019

Severity: 3-Major

Symptoms

DoS stats table shows drops count on tcp-half-open global vector for packets dropped by ltm syn cookie, even when the tcp-half-open vector mitigation threshold is not reached on the vector

Impact

DoS stats table show inaccurate result

Conditions

-- Device DoS tcp-half-open vector is in detect-only mode or mitigate with 64000 limit. -- LTM SYN cookies are enabled.

Workaround

None

Fix Information

After fix, the packets dropped by LTM SYN cookie is not counted against device dos tcp-half-open vector

Behavior Change

Guides & references

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