vMotion on a dedicated NIC

I have two Cisco UCS C220 and two Cisco UCS C240 connected to a Cisco 4500-X. They are all running ESXi 6.5.0. I am looking at doing a big migration in another office with a dozen servers so I am doing my staging on the smaller deployment in my office. I have followed guides on vMware to configure ESXi and on Cisco to configure my switch. Here is how I set it up and what happens:

Created a new vSwitch that was attached to a dedicated 10G interface.

The Cisco switch was setup as an access port. Verified link was up on both Cisco and ESXi.

I did not tag the VMkernel with the VLAN number since it is an access port.

I am not able to ping from one vMotion interface to another using:

ping -I vmk1 -S vmotion [](

Doing a SHOW MAC ADDRESS-TABLE on the Cisco switch shows no MAC on those physical ports.

Created an SVI on my switch and can’t ping the vMotion interfaces.

At this point I tagged the VMkernel with VLAN 203 just to test. The MAC addresses of all the servers show up on the Cisco switch, still no connectivity, and after 4 minutes or so the MAC addresses drop from the Cisco switch and will not return until I change the VMkernel to untagged and back to tagged.

I have tried both 1500 MTU and jumbo frames MTU 9000.

I have rebooted the services on the servers.

Any other suggestions for troubleshooting?

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  1. Enable lldp to facilitate troubleshooting. It will generate packet that will populate the Mac table for instance.
    Can you ping yourself ?
    Do you have arp entries populated?
    Is there some security on the switch?
    In which vlan are the Mac?

  2. There’s a PowerCLI command that will enable you to blink individual physical NICs, are you sure you have the virtual interfaces correctly mapped to the physical interfaces?

  3. Do Cisco switch’s still work where you can tag a port but if you have not configured the VLAN it will fail?
    config-t#Vlan 203

    Other things that jump to mind are subnet is same layer 2?
    If its access it must be untagged. Also, confirm the right ports are the ports you are looking for.

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