How to disable SACK in TCP connections on Windows 11?

Question

I am trying to communicate with incompatible equipment during specific times in the day and want to see how it affects the network. How can I disable SACK in TCP connections on Windows 11?

Answer 1

Hi H M,

Thanks for your post. Based on my research, SACK support in Windows is controlled through Registry at:

• Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
• Value: SackOpts
• Type: REG_DWORD
• Data: 0 to disable
• Reference: Microsoft Word - NetDCU_TCPIP_ParametersConfigurableByUser.htm (fs-net.de)

Best Regards,

Ian Xue

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