NIC team failover, failback, or vMotion results in loss of network connectivity
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NIC team failover, failback, or vMotion results in loss of network connectivity

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Article ID: 339725

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Updated On:

Products

VMware vCenter Server VMware vSphere ESXi

Issue/Introduction


  • When utilizing a NIC team configuration and one of the network adapters in the team fails, network connectivity is lost for all portgroups on the virtual switch on failover or failback.
  • Loss of network connectivity on a virtual machine after vMotion to another ESX/ESXi host.


Environment

VMware vSphere ESXi 7.0.x
VMware vCenter Server 7.0.x
VMware vSphere ESXi 8.0.x
VMware vCenter Server 8.0.x

Resolution

1. When a network adapter or link within a NIC team fails, all traffic is rerouted over the available adapter in the team.
    Note: In an Active/Standby configuration, the Standby adapter takes over for the failed Active adapter and in case of an Active/Active configuration the other available Active adapter takes over for the failed Active adapter.
2. After a vMotion of a virtual machine, its network traffic is directed over one of the destination's network adapters.
 
If the network connectivity of a virtual machine is lost after either of the above-mentioned events, perform following troubleshooting steps:
 
Validate that each troubleshooting step below is true for your environment. Each step provides instructions or a link to a document, in order to eliminate possible causes and take corrective action as necessary. The steps are ordered in the most appropriate sequence to isolate the issue and identify the proper resolution. Do not skip a step.
 
  1. Verify that the physical network adapters are supported. For more information, see  Identifying ESXi host network adapter compatibility
  2. Verify that all network links in the team are up. For more information, see Verifying network links (100Verifying network links for ESX/ESXi hosts.

  3. Verify that the physical switch ports are configured consistently among all network adapters in the team. Ensure VLAN and link aggregation protocol (if any) are configured correctly on the physical switch ports.

  4. Verify that the vSwitch of vDS has correct load balance policy configured. The default load balancing policy is Route based on the originating virtual port ID. If the physical switch is using link aggregation, Route based on IP hash load balancing must be used.
    For more information, see Host requirements for link aggregation (etherchannel, port channel, or LACP) in ESXi 

  5. Verify that port security is not configured on the physical switch ports. For more information, see Loss of network connectivity when Cisco port security is configured on the physical switch.

  6. Verify that portfast (or equivalent) is enabled on all of the ESX/ESXi host's physical switch ports. For more information, see STP may cause temporary loss of network connectivity when a failover or failback event occurs.

  7. Verify that the network configuration on the ESX/ESXi host is optimized for the best performance, including speed and duplex settings. For more information, see Configuring the speed and duplex of an ESXi host network adapter.

  8. Check if there are available ports on the vSwitch by running the command # esxcfg-vswitch -l.
Note: If your problem still exists after trying the steps in this article:



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