Large packet loss at the guest OS level on the VMXNET3 vNIC in ESXi (2039495)
To resolve this issue, ensure that there is no traffic filtering occurring (for example, with a mail filter). After eliminating this possibility, slowly increase the number of buffers in the guest operating system.
- Click Start > Control Panel > Device Manager.
- Right-click vmxnet3 and click Properties.
- Click the Advanced tab.
- Click Small Rx Buffers and increase the value. The default value is 512 and the maximum is 8192.
- Click Rx Ring #1 Size and increase the value. The default value is 1024 and the maximum is 4096.
- This issue is seen in the Windows guest OS with a VMXNET3 vNIC. It can occur with versions besides 2008 R2.
- It is important to increase the value of Small Rx Buffers and Rx Ring #1 gradually to avoid drastically increasing the memory overhead on the host and possibly causing performance issues if resources are close to capacity.
- If this issue occurs on only 2-3 virtual machines, set the value of Small Rx Buffers and Rx Ring #1 to the maximum value. Monitor virtual machine performance to see if this resolves the issue.
- The Small Rx Buffers and Rx Ring #1 variables affect non-jumbo frame traffic only on the adapter.
For more information on this issue, see: