Network Connectivity Lost Due to Physical Link Down

Products

• VMware vSphere ESXi

Issue/Introduction

• This event indicates that one or more port groups in the ESX host have lost connectivity to the network.
  If vmnic1 is the only uplink on vSwitch0 and VM Network is the only port group connected to this virtual switch, then this error occurs if vmnic1 goes down

         

Lost network connectivity on virtual switch "vSwitch0".Physical NIC vmnic1 is down. Affected portgroups: "VM Network"

        The services associated with the affected port groups are disconnected from the associated physical networks: virtual machines, service console, VMotion, NFS, iSCSI,              and Management Services..

 

• If the physical switch on the network  is rebooted and because of which the  network connectivity is lost we get the below alarm.
  
  

  Network connectivity lost   Triggered Alarm

  
  
  
  

Environment

VMware ESXi
VMware Vcenter

Resolution

To determine the actual failure or to eliminate possible issues:

1. Check the status of the vmnic from either the VMware vSphere Client or the ESX service console:
   • To check the status from the vSphere Client:
     1. Select the ESX host and click the Configuration tab.
     2. Click Networking.
     3. The vmnics currently assigned to virtual switches are displayed in the diagrams. If a vmnic displays a red X, that link is currently down.
         
   • To check the status from the ESX service console, run this command:
     
     [root@server root]# esxcfg-nics -l
     
     The output appears similar to this:
     
     Name PCI Driver Link Speed Duplex Description
     vmnic0 04:04.00 tg3 Up 1000Mbps Full Broadcom BCM5780 Gigabit Ethernet
     vmnic1 04:04.01 tg3 Up 1000Mbps Full Broadcom BCM5780 Gigabit Ethernet
     
     The Link column specifies the status of the link between the network adapter and the physical switch. The status can be either Up or Down. If there are several network adapters, with some being up and some down, you might have to verify that they are connected to the intended physical switch ports. This can be done by bringing down each of the ESX host's ports on the physical switch and running the esxcfg-nics -l command to observe which vmnic is affected.
      
2. Check that the vmnic referred to in the event message is still connected to the switch and configured properly:
   1. Make sure that the network cable is still connected to the switch and to the host.
   2. Check that the switch connected to the system is still functioning properly and has not been misconfigured. Refer to the switch documentation for details.
   3. Check for activity between the physical switch and the vmnic. This might be indicated either by a network trace or activity LEDs.
   4. Check for network port settings on the physical switch.
       
3. Reconfigure the service console IP address if the affected vmnic is associated with a service console.
4. If you had earlier received an alarm about the links down message even when the NICs are up and running, restart the vCenter Server services. This clears the stale alarm.

If the issue is due to your hardware, contact your hardware vendor for a replacement.

 

Additional Information

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