Last Modified: Jul 18, 2026
Affected Product(s):
BIG-IP LTM
Known Affected Versions:
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, 14.0.0, 14.0.0.1, 14.0.0.2, 14.0.0.3, 14.0.0.4
Fixed In:
14.1.0, 14.0.0.5, 13.1.1.2, 12.1.4
Opened: Jul 04, 2017 Severity: 3-Major
IP ToS field may not be preserved on forwarding in a FastL4 virtual server when syncookie is activated.
IP ToS header is not forwarded to the serverside.
-- FastL4 ip-forwarding virtual server. -- ToS in passthrough mode. -- Syncookie is activated in hardware mode. -- On a hardware platform with ePVA.
None.
The BIG-IP system now forwards IP ToS in syncookie mode.