Issue : Configure Management Network option is Grayed out into ESXi

Last week I got into an issue of one of my client into Vsphere environment where one of its ESXi went done out of the network. Issue was IP address was showing 0.0.0.0 on main Esxi screen and when I tried to change the network configuration, its " Configure Management network option was greyed out.

 I tried to gid into it and try to analyis its vmKernal and vmwarning logs. What I found is its VMkernal switch got removed due to unexpected reason.

So to resolve the issue I tried to reconfigure its vswitch0 (vmk0) by going into Tech Mode of that Exi. Below are the steps which I followed to resolve the issue.

1) Login to ESXi

2) Press F2, Check if you "Configure Management network" is greyed out or not"
if yes,  follow below

3) Press ALT+F1 to move the ESXi screen to tech mode ( This is command line like dos)

4) login with root account

5) Run the following command into it

esxcli network ip interface add --interface-name=vmk0 --portgroup-name="Management Network"

6) Type  "exit" to exit  and Press ALT+F2 to go to yellow screen of ESXi

7) Now check again if configure management network is greyed out.. If its still greyed out.

Pls follow below points.

8) Go back to Tech mode Alt+F1

9) Type below command  

-Note: In IPaddress type your IP, and in netmask type your subnet mask

 esxcli network ip interface ipv4 set  --interface-name=vmk0 --ipv4=10.10.0.106 --netmask=255.255.255.0 --type=static

Example:

esxcli network ip interface ipv4 set  --interface-name=vmk0 --ipv4=192.168.189 netmask=255.255.255.0  --type=static

IPADDRESS = ESXi ip address

subnet mask = ESXi subnet mask

10) Go back to Yellow screen by ALT+F2 and check if configure management network is visible now

11) Configure the networking by giving its IPADDRESS, SUBNET MASK, GATEWAY AND DNS ADDRESS.