vmnic# has lost connection

Products

• VMware vSphere ESXi

Issue/Introduction

• vmnic# showing down in the NIC list on the host:

  [root@ESXi-host:~] esxcli network nic list
  Name    PCI Device    Driver  Admin Status  Link Status  Speed  Duplex  MAC Address        MTU   Description
  ------  ------------  ------  ------------  -----------  -----  ------  -----------------  ----  -----------
  vmnic0  0000:19:00.0  i40en   Up            Up           10000  Full    ##:##:##:##:##:##  1500  Intel(R) Ethernet Controller X710 for 10GbE SFP+
  vmnic1  0000:19:00.1  i40en   Up            Down             0  Half    ##:##:##:##:##:##  1500  Intel(R) Ethernet Controller X710 for 10GbE SFP+

• vobd.log entry found for the vmnic in question:

  2024-10-08T08:08:32.905Z: [netCorrelator] 2996811237745us: [vob.net.pg.uplink.transition.down] Uplink: vmnic1 is down. Affected portgroup: Management Network. 1 uplinks up. Failed criteria: 128

Environment

VMware vSphere ESXi

Cause

Failed Criteria 128 is the driver reporting a link state down. This can be caused by unplugging the network cable or administratively shutting down the physical switchport. If this was not an intended link outage it will likely be an issue with the driver, firmware, SFP+ module, cable, and/or switchport of the physical switch.

In this scenario, the SFP+ module for the vmnic is faulty.

Resolution

Replace faulty SFP+ module

Additional Information

Network adapter (vmnic) is down or fails with a Failed Criteria Code