Ravindra

19 Jul 2010 2:52 PM

Microsoft security guides for Vista, Windows 7 , 2008 and 2008 R2 recommend a value of 3 for the TcpMaxdataRetransmissions key. This key is also mentioned in the TCP/IP Registry Values for Microsoft Windows Vista and Windows Server 2008 document and it also has the same recommendation.

However your note above "Important note: If OS is Windows Vista/2008, the number of TCP Keepalive attempts are hardcoded to 10 and could not be adjusted via the registry. " , what does this mean. Is there some error somewhere. Please advise. Thanks.

MuratKa1

23 Jul 2010 1:03 PM

Thank you for the feedback Ravindra. There could be some misleading information in some documentations, if you could send me Microsoft links for those documents that you refer to, I can internally initiate change request. Back to how it works in Windows Vista onwards, you can also get more information at the below link:

msdn.microsoft.com/.../ee470551(VS.85).aspx SO_KEEPALIVE Socket Option

...

On Windows Vista and later, the number of keep-alive probes (data retransmissions) is set to 10 and cannot be changed.

...

Thanks,

Murat

BillE

2 Apr 2014 9:49 PM

For windows sockets are tcp keep alives enabled by default ?

What about for WinHTTP conversations that use windows sockets under the covers ?

Thanks,

Bill