5 Replies Latest reply on Oct 28, 2019 5:14 AM by Amin Masoudifard

    Enumeration of VMNICs

    StephenMoll Hot Shot

      How is the enumeration of physical NICs to VMNICs done in ESXi?

      We are noticing a difference in the order in which this occurs between different batches of hosts? What are the potential reasons for this?

      Can we influence the enumeration order in any way to ensure consistency?

       

      The compute platforms are Dell M1000e blades. On one batch of blades (the newest ones) the enumeration of the fabric NICs to VMNIC numbers is the same for v5.1 and 6.5 of ESXi. With the oldest ones, the enumeration order is different. Some clues as to why this happens would be much appreciated.

        • 1. Re: Enumeration of VMNICs
          Tibmeister Enthusiast

          If memory serves, they are enumerated in order of appearance on the PCI bus, but here's a KB that details how this is done in ESXi 5.5 and above.

           

          VMware Knowledge Base

          1 person found this helpful
          • 2. Re: Enumeration of VMNICs
            StephenMoll Hot Shot

            Ah! That looks very interesting. I'll take a closer look at that on Monday.

            Many thanks.

            • 3. Re: Enumeration of VMNICs
              Amin Masoudifard Expert

              ESXi has a device manager that will retrieve the list of available devices on the motherboard to assigns their device name. So in most of times it will consider locally onboard devices for numbering, then other installed devices on motherboard slots (like PCI-E NICs). Just remember following points:

              1. Device replacement don't change existing port numbers.

              2. If you remove a device, it's Alias name will be available for using on next names

              3. If there is a different numbering in rear cases like your issue or after an upgrade, you can fix it by Host Profile feature.

              Please mark my comment as the Correct Answer if this solution resolved your problem
              • 4. Re: Enumeration of VMNICs
                StephenMoll Hot Shot

                Are there any known differences between v5.5 and v6.5 in the way the enumeration works?

                 

                In case my original explanation isn't clear?

                 

                For the original blades, ESXi 5.5 and 6.5 produce a different vmnic to physcial port mapping.

                For the revised (newer batch) of blades, ESXi 5.5 and 6.5 produce the same mapping.

                 

                The problem is that the blades are supposed to be interchangeable, but with the various ports aligned to different networks for different purposes, the behaviour described above results in some problems for us.

                • 5. Re: Enumeration of VMNICs
                  Amin Masoudifard Expert

                  Are there any known differences between v5.5 and v6.5 in the way the enumeration works?

                  I don't think there is any architectural different for adapter enumeration (I Checked the vSphere 6.5 Networking Guide Docs)

                  But you can change the order of the adapter manually. Check this link

                  Please mark my comment as the Correct Answer if this solution resolved your problem