Last Modified: Jul 18, 2026
Affected Product(s):
BIG-IP LTM
Known Affected Versions:
11.5.1, 11.5.1 hf1, 11.5.1 hf2, 11.5.1 hf3, 11.5.1 hf4, 11.5.1 hf5, 11.5.1 hf6, 11.5.1 hf7, 11.5.1 hf8, 11.5.1 hf9, 11.5.1 hf10, 11.5.1 hf11, 11.5.2, 11.5.2 hf1, 11.5.3, 11.5.3 hf1, 11.5.3 hf2, 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, 12.0.0, 12.0.0 hf1, 12.0.0 hf2, 12.0.0 hf3, 12.0.0 hf4
Fixed In:
12.1.0, 11.6.1
Opened: Feb 05, 2015 Severity: 3-Major Related Article:
K13627243
Sending unsolicited ACK to a virtual server increments the counter 'Total Software Rejected' from tmsh show ltm virtual 'name_of_virtual_server' when syn cookie status is not activated.
Potentially inaccurate statistics in tmsh show ltm virtual.
This has been observed under the following conditions: 1. The client sends a SYN, the LTM sends an SYN/ACK and then the client sends a bad ACK. 2. A client sends an ACK for a connection that does not exist in the connection table (either it never existed or had been closed).
None.
In this release, the system increments the syncookie reject stat only if a bad ACK could correspond to a syncookie the system issued.