=== Total loss of ESXi Management Network Settings === **Solution:** Per commandline we created a new vSwitch. Then a dedicated pNIC (vmnic0) was added to the new vSwitch and a portgroup (Management Network), too. The last step was to set the IP address/Subnet. After a reconnect from the host in vCenter everything was fine! **Used Commands:** esxcfg-vswitch -a vSwitch1 With this command you can create a new vSwitch named: “vSwitch1” esxcfg-vswitch -A “Management Network” vSwitch1 now you can assign a portgroup “Management Network” to the new vSwitch1 esxcfg-vswitch -L vmnic0 vSwitch1 this step adds pNIC “vmnic0” to the vSwitch1 esxcfg-vmknic -a “Management Network” -i 160.xxx.xxx.xxx -n 255.xxx.xxx.xxx this command will set the IP address/Subnet If necessary you can use the parameter -l (for list) to show the current configuration! "Stolen" from [[https://www.virtuallyghetto.com/2014/01/how-to-restart-esxi-management-network.html]]