In previous releases, TCP Selective Acknowledgement (aka: TCP SACK) could be enabled on LoadMaster only by logging into the OS. With this release, you can now control the TCP SACK setting in the UI and via the API. This global setting is located in the UI under System Configuration > Logging Options > System Log Files > Debug Options. Note that TCP SACK is a global setting (i.e., it affects all TCP traffic) and is disabled by default. If you change the default setting, your change will persist across future LoadMaster reboots.