Link state up or down for a vmnic interface on ESXi

Products

• VMware vSphere ESXi

Issue/Introduction

This article provides commands to change the link state of the physical interface from the command line in ESXi. It also describes what each NIC link state means. 

Resolution

To check the status of the vmnic from the ESXi host, follow the steps below

• Login to the ESXi host as user root via putty/ssh
• Run the command esxcli network nic list or esxcfg-nics -l

Sample output of the command :-

Name     PCI Device    Driver  Admin Status  Link Status   Speed  Duplex  MAC Address         MTU  Description
-------  ------------  ------  ------------  -----------  ------  ------  -----------------  ----  -----------
vmnic0   0000:01:00.0  ixgben  Up            Up             1000  Full    ec:f4:bb:##:##:##  1500  Intel(R) Ethernet Controller X540-AT2
vmnic1   0000:01:00.1  ixgben  Up            Up             1000  Full    ec:f4:bb:##:##:##  1500  Intel(R) Ethernet Controller X540-AT2

Note: The "Admin Status" is the only option that can be managed/modified via ESXi commands. The "Link Status" column specifies the status of the link between the physical network adapter vmnicX and the physical switch port.

To change the "Admin Status" of the physical interface vmnicX from the command line of the ESXi host, follow the steps below

• Log in to the ESXi host as user root via putty/ssh
• Toggle through the "Admin Status" of the uplink vmnicX by running the commands below.

esxcli network nic down -n vmnicX  --> This puts the interface vmnicX down
esxcli network nic up -n vmnicX   --> This gets the interface vmnicX up

Where X is the vmnic number (for example,vmnic0)

Important: If the "Link Status" shows as down, then contact the host hardware vendor for troubleshooting.

Note: Only cards running with auto-negotiation/10Mb/100Mb/1000Mb/10000Mb speeds are supported.