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

Symptoms:
  • 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 vCenter Server 6.7.x
VMware vSphere ESXi 6.7.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 ESX/ESXi host network adapter compatibility (1003685).

  2. Verify that all network links in the team are up. For more information, see Verifying network links (1003724).

  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 for ESX and ESXi (1001938) and the VMware Virtual Networking Concepts guide.

  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 (1002811).

  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 (1003804).
  7. Verify the integrity of the physical network adapter. For more information, see Verifying the integrity of the physical network adapter on an ESX/ESXi host (1003686).

  8. 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 ESX/ESXi host network adapter (1004089).

  9. Check if there are available ports on the vSwitch by running the command # esxcfg-vswitch -l.For more information, see No network connectivity if all ports are in use (1009103).
Note: If your problem still exists after trying the steps in this article:



Additional Information

Starting with vSphere 5.1, LACP is supported on distributed vSwitches and requires additional configuration. For more information, see Enabling or disabling LACP on an Uplink Port Group using the vSphere Web Client (2034277).

For more information, NIC teaming in ESXi and ESX (1004088).

Loss of network connectivity when Cisco port security is configured on the physical switch
Identifying ESX/ESXi host network adapter compatibility
Verifying the integrity of the physical network adapter on an ESX/ESXi host
Verifying network links
STP may cause temporary loss of network connectivity when a failover or failback event occurs
NIC teaming in ESXi and ESX
NIC チームのフェイルオーバー、フェイルバック、または vMotion のネットワーク接続が切断される
网卡组故障切换、故障恢复或 vMotion 导致网络连接丢失
Collecting diagnostic information for VMware ESX/ESXi