vSphere 6.5 + few NIC 10G = slow network speed

[malefik]

Hello, colleagues!

1. We have:

- VCSA 6.5.0.21000

- a few ESXi, 6.5.0, 8935087

- 2 physical switches DELL FORCE10 S4810 (switches are combined in LAG)

- 2 NIC 10G Intel X520 (82599) on each host (each NIC is connected to different physical switches)

- everywhere included MTU9000

2. At the level of dSwith is configured:

- association of NIC in LAG (active mode, Load Balancing: source and destination ip address tcp/udp port and vlan)

- Private VLAN port group, all the necessary settings are also made on physical switches.

3. Test machines Windows Server 2012R2 with adapters vmxnet3 (VM version 13) and VMware-tools-10.2.5-8068406 have been prepared. All machines are located on the same subnet and in the same port group.

So, should I get the total speed between hosts around 20G and a similar speed between virtual machines?

But:

- I'm testing iperf between hosts - speed about 8G

- I'm testing iperf between VMs hosted on the same host - speed 3-3.5G

- I'm testing iperf between VMs hosted on different hosts - speed only 1-2G

What could be the problem?

[HassanAlKak88]

Hello,

Kindly share a print-screen for your physical adapter Tab from vsphere web client. And a second one for your vDS topology.

And third one for your teaming policy at port group level. and also for the LAG settings.

[malefik]

Tnx for you help!