Let’s Panic: ESXi failover not working, using Static LAG/etherchannel


There was once… a customer who was concernced about the network-wise failover on the ESXi-level, which was not working as he expected it to. To shed some light on the complete scenario…

Configuration

The configuration is pretty simple:

  • The switch is vSwitch0
  • As Failover order there are two vmnic adapters configured as active. (Let’s say vmnic0 and vmnic1)
  • Load balancing is Route based on IP hash (Static LAG/etherchannel/trunk set on physical switch)
  • Network failure detection is Link status only
  • Notify switches is Yes.

Taking above into consideration: When disabling one of the two active vmnic adapters on ESXi using esxcli network nic down -n vmnicX you would expect a failover to occur – don’t you? The truth is: Not necessarily. Let’s go into detail…

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