Enable LRO Globally on a Windows Virtual Machine

To use LRO on a VMXNET3 adapter on a virtual machine that runs Windows 8 and later or Windows Server 2012 and later, you must enable LRO globally on the guest operating system. On Windows, the LRO technology is also referred to as Receive Side Coalescing (RSC).

Procedure

1. To verify whether LRO is disabled globally on a Windows Windows 8 and later or Windows Server 2012 guest OS, run the netsh int tcp show global command at the command prompt.

   netsh int tcp show global

   The command displays the status of the global TCP parameters that are set on the Windows 8.x OS.

   TCP Global Parameters
   ----------------------------------------------
   Receive-Side Scaling State          : enabled
   Chimney Offload State               : disabled
   NetDMA State                        : disabled
   Direct Cache Access (DCA)           : disabled
   Receive Window Auto-Tuning Level    : normal
   Add-On Congestion Control Provider  : none
   ECN Capability                      : disabled
   RFC 1323 Timestamps                 : disabled
   Initial RTO                         : 3000
   Receive Segment Coalescing State    : disabled 

   If LRO is globally disabled on the Windows 8 and later or Windows Server 2012 machine, the Receive Segment Coalescing State property appears as disabled.

2. To enable LRO globally on the Windows OS, run the netsh int tcp set global command at the command prompt:

    netsh int tcp set global rsc=enabled

What to do next

Enable LRO for the VMXNET3 adapter on the Windows 8 and later or Windows Server 2012 virtual machine. See Enable or Disable LRO on a VMXNET3 Adapter on a Windows Virtual Machine.