Last Modified: Mar 19, 2024
Affected Product(s):
BIG-IP LTM
Known Affected Versions:
10.2.4, 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 HF1, 11.5.3 HF1, 11.5.3 HF2, 11.5.4 HF1, 11.5.4 HF2, 11.5.4 HF3, 11.5.4 HF4, 11.2.1, 11.3.0, 11.4.0, 11.4.1, 11.5.0, 11.5.1, 11.5.2, 11.5.3, 11.6.0, 11.6.1, 11.6.2, 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, 11.6.5.2, 11.6.5.3, 12.1.0 HF1, 12.1.0 HF2, 12.1.1 HF1, 12.1.1 HF2, 12.1.2 HF1, 12.1.2 HF2
Fixed In:
12.0.0, 11.6.1 HF1, 11.5.4, 11.4.1 HF9
Opened: Jan 24, 2015 Severity: 3-Major
Incoming SYN causes the BIG-IP system to generate ACK instead of SYN-ACK.
Client will generate RST and the connection must be re-tried.
This can occur when the following conditions are met: -- IP addresses and ports of SYN match an existing connection; -- Sequence number of the SYN is greater than 2^31+ from previously sent FIN; -- Existing connection is in TIME_WAIT state; -- Virtual server has time_wait_recycle enabled.
Set time-wait-timeout to 1 millisecond per K12673.
The BIG-IP system will no longer generate an ACK to incoming SYNs which match an existing connection that cannot be recycled, and it will drop them instead.