Last Modified: Sep 27, 2024
Affected Product(s):
BIG-IP LTM
Known Affected Versions:
17.1.1.3, 17.1.1.4
Opened: Sep 03, 2024 Severity: 3-Major
When hardware SYN cookie mode is activated, the hardware will negotiate window scaling with the client, but TMM still assumes no window scaling is involved.
TMM interprets the client’s advertising in a very small window, which reduces its performance.
When the receive window size and send buffer size are both at or below 65535, TMM establishes the TCP connection without using TCP window scaling. This can happen if a profile such as this one is used: - ltm profile tcp tcp-legacy - ltm profile tcp tcp-wan-optimized - since they have the following settings: - receive-window-size 65535 - send-buffer-size 65535
Increase to 65536 or higher for either one of the following: - receive-window-size - send-buffer-size
None