I have an ESXi 6.7 host, with two VM:
Windows 10 (+VMware Tools)
Debian 10
All VM have VMXNET3 interface and connected to same vSwitch. vSwitch has only one uplink to the real gigabit card. This card connected to a real (native) computer with Windows 10.
Very simple network.
All VM and real computer interfaces, the vSwitch, and the uplink adapter have MTU 9000/9014
And measured the speed across hosts with iperf3, results:
VM Win10 - VM Deb10: ~6 Gbps (RX/TX)
VM Deb10 - Real Win10: ~900 Mbps (RX/TX)
VM Win10 - Real Win10: ~150 Mbps (RX/TX)
I have problem with 150 Mbps only. Where is the bottleneck? I can't figure out...
Thank you for the help.