Disable LRO

From DocWiki

(Difference between revisions)
Jump to: navigation, search
(Reinstated the lost content as on the docwiki)
m (1 revision)

Revision as of 18:21, 1 May 2013

Go to: Implementing Virtualization Deployments

Note Note: After upgrading the ESXi host to 4.1 and upgrading VMs to VMwareTools to 4.1, you may experience slow TCP performance on VMs running on the 4.1 ESXi host. You can address this situation by disabling Large Receive Offload (LRO) on the ESXi host. See further below.
Note Note: If you're running CUCM 8.6, UCCX/ IP IVR 9.0 and above (i.e., UC applications using VOS/ RHEL 5+), the Linux version used in these releases is compatible with LRO, you don't have to worry about the settings (disable LRO is not required) on the host or which version of ESXi is running. However, Disabling LRO is required for CUCM versions 8.0 and 8.5 irrespective of ESXi version.

To disable LRO, follow this procedure:

  1. Log into the ESXi host or its vCenter with vSphere Client.
  2. Select the host > Configuration > Advanced Settings.
  3. Select Net and scroll down slightly more than half way.
  4. Set the following parameters from 1 to 0:
    • Net.VmxnetSwLROSL
    • Net.Vmxnet3SwLRO
    • Net.Vmxnet3HwLRO
    • Net.Vmxnet2SwLRO
    • Net.Vmxnet2HwLRO
  5. Reboot the ESXi host to activate these changes.

Your guest VMs should now have normal TCP networking performance.

Back to: Unified Communications in a Virtualized Environment

Rating: 4.1/5 (69 votes cast)

Personal tools