Warning: Enable Receive Side Scaling (RSS) on a network adapter

Symptom: In Windows Server 2008, Windows Server 2008 R2, Windows Server 2012, and Windows Server 2012 R2 you receive the following Warning when running the Microsoft Best Practices Analyzer.

Severity: Warning
Enable Receive Side Scaling (RSS) on a network adapter
Server Manager - Best Practices Analyzer - Warning - Enable Receive Side Scaling RSS on a network adapter

What is Receive Side Scaling (RSS)?

Per Microsoft’s website, Virtual Receive-side scaling (RSS) is a feature in Windows Server® 2012 R2 that allows the load from a virtual network adapter to be distributed across multiple virtual processors in a virtual machine.

Solution: Complete the following steps below to enable Receive-side scaling (RSS) on a network adapter.

  1. Open up an elevated command prompt
    Elevated Command Prompt
  2. Execute the following command
    1. netsh interface tcp set global rss=enabled
      command prompt - netsh interface tcp set global rss enabled
  3. At this point, Receive Side Scaling should be enabled.  Optionally, you can verify this in the Windows GUI.  Follow the steps below for verification.
    1. Execute the following command to open up device manager
      1. DEVMGMT.msc
        command prompt - devmgmt
    2. Expand Network adapters, right click on your adapter and select Properties
      device manager - network adapters - properties
    3. Select the Advanced tab and find Receive Side Scaling.  Set this to Enabled if it isn’t already.
      Network Adapter Properties - Advanced - Receive Side Scaling

Notes:
An official KB article on this issue can be found here: http://technet.microsoft.com/en-us/library/gg162712(v=ws.10).aspx
An official KB article about Receive Side Scaling can be found here: http://technet.microsoft.com/en-us/library/dn383582.aspx

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