6.5.1

Table Of Contents
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
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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.
NetQueue and Networking Performance
NetQueue takes advantage of the ability of some network adapters to deliver network traffic to the system
in multiple receive queues that can be processed separately, allowing processing to be scaled to multiple
CPUs, improving receive-side networking performance.
vSphere Networking
VMware, Inc. 178