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