Host connectivity lost after network reconfiguration

Products

• VMware vSphere ESXi

Issue/Introduction

The ESXi host has lost connectivity after changes were made to the host network configuration, virtual switch or external network.

The connection is not restored after a network reset in the DCUI.

Cause

There are cases where reconfiguration of an ESXi host may inadvertently lead to loss of network connectivity.

The options in the console UI (DCUI) under "Network Restore Options" followed by "Restore Network Settings" can usually restore default settings and allow reconfiguration in a graphical interface that is easier to use. However, in some cases, this option does not complete properly or the settings will not work to connect to your network.

In these cases, manual reconfiguration is required.

 

Resolution

Identify an unassigned vswitch or vmnic that can be used to connect the host.

 

If a standard virtual switch with the appropriate vmnic uplink exists, it can be reused.

If necessary:

Remove a vmnic using the command esxcfg-vswitch -Q <vmnicX> -V <PortIDX> <vDSName>

A standard switch can be created using the command esxcli network vswitch standard add --vswitch-name=<vSwitchName>

Associate the vmnic to your new switch using the command esxcli network vswitch standard uplink add --uplink-name=<vmnic#> --vswitch-name=<vSwitchName>

Create a port group using the command esxcli network vswitch standard portgroup add --portgroup-name=<PortgroupName> --vswitch-name=<vSwitchName>

Refer to KB article vCenter network connectivity lost - Recover vCenter network when connected to a Distributed Switch for more details on the usage of these commands

 

Configure a new VMkernel with the command

esxcli <conn_options> network ip interface add --interface-name=vmk<X> --portgroup-name=<my_portgroup>

Assign the IP address using the DCUI or using the command

esxcli <conn_options> network ip interface ipv4 set --ipv4=<ip_address> --netmask=255.255.255.0 --type=<value> --interface-name=vmk<X>

Refer to TechDocs article Add and Configure an IPv4 VMkernel Network Interface with ESXCLI for more details on the usage of these commands

 

Creating the new VMkernel restores host connectivity.

Additional Information

Refer to KB article vCenter network connectivity lost - Recover vCenter network when connected to a Distributed Switch for a similar process that is used when a host has lost connectivity to vCenter.