Networking performance between 2 VMs

[usao]

I have 2x VM's, both located on the same ESXi6 server.

The vswitch is setup correctly and both VM's are on that same switch.

The network is a 1GB interfrace, and both VM's have 1GB interfaces.

However, I can only achieve 1MB/s between the 2 VMs.

Looking for ways to diagnose and fix this issue.

Suggestions, questions, clarifications, please let me know.

SCP between VMs: 0% 1865MB 963.7KB/s 219:48:49

VM1# ethtool eth0

Settings for eth0:

        Supported ports: [ TP ]

        Supported link modes:   1000baseT/Full

                                10000baseT/Full

        Supported pause frame use: No

        Supports auto-negotiation: No

        Advertised link modes:  Not reported

        Advertised pause frame use: No

        Advertised auto-negotiation: No

        Speed: 10000Mb/s

        Duplex: Full

        Port: Twisted Pair

        PHYAD: 0

        Transceiver: internal

        Auto-negotiation: off

        MDI-X: Unknown

        Supports Wake-on: uag

        Wake-on: d

        Link detected: yes

VM2# ethtool eth0

Settings for eth0:

        Supported ports: [ TP ]

        Supported link modes:   1000baseT/Full

                                10000baseT/Full

        Supported pause frame use: No

        Supports auto-negotiation: No

        Advertised link modes:  Not reported

        Advertised pause frame use: No

        Advertised auto-negotiation: No

        Speed: 10000Mb/s

        Duplex: Full

        Port: Twisted Pair

        PHYAD: 0

        Transceiver: internal

        Auto-negotiation: off

        MDI-X: Unknown

        Supports Wake-on: uag

        Wake-on: d

        Link detected: yes

[Miquel_A]

Hi,

Do you have more machines on those hosts which uses  the same interfaces? are you copying over files or similar?

[usao]

Yes, I have several other VM's similarly configured, and they can transfer files without issues.

Not sure what about these 2 VM's that is causing the problem.

Aditionally, when I transfer the file from VM1 -> physical host and then from physical host -> VM2, those transfers run at the expected/normal speeds for Gigabit ethernet.

It's only when I go directly between the 2 VMs that the issue presents itself.

[WhiteForEver · Accepted solution]

Try to create new vSwitch without physical NIC, put both VMs into and try to check network speed between them.

[usao]

We ended up resolving this issue by changing some settings on the vswitch.

[rampeter]

Can you share the setting which helped to resolve your issue