Thursday, April 18, 2013

Hack :Tuning Windows For TCP/IP Performance.

Today I m struggling lot to establish  VMs guest OS to access shared folder of host Hype-v Windows server 2008 R2. After wrecking my head and intense search I got the solution for the given problem in microsoft support site. Its very unusual besides having set right at first place never thought tuning network tcp/ip will resolve this. Still its hard on my part for not getting answers why running following below command solved my problem. Yup! I'm not a network or infra guy.. just thought to file this findings in my blogpost for future reference.


  1. netsh int tcp set global chimney=disabled
  2. netsh int tcp set global NetDMA=disabled
  3. netsh interface tcp set global autotuning=disabled

Where I ended up...
http://social.technet.microsoft.com/Forums/en-US/winserverhyperv/thread/82c9371a-eab9-4526-ba34-81d1f3bdc141/

Final Verdict..

http://support.microsoft.com/kb/951037

What it state.
TCP Chimney Offload overview TCP Chimney Offload is a networking technology that helps transfer the workload from the CPU to a network adapter during network data transfer. In Windows Server 2008, TCP Chimney Offload enables the Windows networking subsystem to offload the processing of a TCP/IP connection to a network adapter that includes special support for TCP/IP offload processing.
TCP Chimney Offload is available in all versions of Windows Server 2008 and Windows Vista. Both TCP/IPv4 connections and TCP/IPv6 connections can be offloaded if the network adapter supports this feature.

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