Test your ESXi network resiliency with ESXCLI

After configuring the network portion for your ESXi servers you need to test if the redundancy is working as accepted. From the ESXi layer you can bringing down/up one or more uplinks  to test the network resilience.  No longer you need to pull out the UTP cables. Since ESXi5 this can be done by using the esxcli network nic down/up command.

First log in to ESXi using for example using Tech Support Mode

  • Get a overview of the installed vmnics 
esxcli network nic list
  • Bring a vmnic down 
esxcli network nic down –n vmnicNumber
  • Bring a vmnic up 
esxcli network nic up –n vmnicNumber

Only auto-negotiation 10Mb/100Mb/1000Mb/10000Mb speeds vmnics are supported. FlexNics with different speed are not supported.

Related posts:

  1. Useful ESXCLI commands for configuring and troubleshooting ESXi environments
  2. Create a bootable VMware ESXi 5 USB stick in Windows and perform a scripted installation
  3. Create a VMware ESXi 5 PXE unattended scripted installation using Windows
  4. Install VMware ESXi 4.1 from bootable USB stick
  5. Upgrading to VMware ESXi 5

2 thoughts on “Test your ESXi network resiliency with ESXCLI”

  1. But note that vim API reports only operational state not administrative state. So the esxcli list won’t say why the nic is down properly nor will the GUI. Only the snmp agent will.

    One can grep /etc/esx.conf to see this esxcli cmd writes there.

  2. One more issue with this cmd which will confuse network admins.
    Real Ethernet switches power down the link physically when a nic is admistratively disabled. In fact the IEEE spec says this must be done.
    yet vmware virtual switch leaves the link up so it black holes traffic and wastes engineers time figuring out what happened.

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