How to change/update DNS Server IP address for vCenter Server

Products

• VMware vCenter Server 8.0
• VMware vCenter Server 7.0
• VMware vCenter Server 6.0
• VMware vCenter Server

Issue/Introduction

When administrators want to edit the DNS settings and select which DNS server to use for vCenter server.

Environment

• VMware vCenter Server Appliance 8.0
• VMware vCenter Server Appliance 7.0
• VMware vCenter Server Appliance 6.0

Prerequisites prior to changing the DNS IP for vCenter server.

• To change the IP address of the appliance, verify that the system name of the appliance is an FQDN. If, during the deployment of the appliance, you set an IP address as a system name, you cannot change the IP address after the deployment. The system name is always used as a primary network identifier.

• Verify that the user who logs in to the vCenter Server instance in the vCenter Server Appliance is a member of the SystemConfiguration. Administrators group in vCenter Single Sign-On.

• Verify that the new DNS also has the correct host record for the vCenter is updated in both forward and reverse lookup zone.

Cause

When we need to perform a configuration change for the DNS IP for vCenter server

Resolution

Change DNS server using VCSA web console:

In order to change the DNS, you need to log in to VAMI https://appliance-ip-address-or-FQDN:5480 and login using the root user and password that you set when you installed VCSA.

1. Login and go to Networking. Then click EDIT in the top right corner for Network settings to change the DNS servers for vCenter.

2. Select the Network Adapter on which you want to make changes and click NEXT.

3. On the Edit settings section, you can change the DNS server IP and Hostname. Below Hostname and DNS you can change IP settings for NIC

4. Enter the username and password for the SSO credentials ([email protected]).

5. Review the settings and accept the acknowledgment that you have a vCenter backup before continuing with the network configuration. Click FINISH.

You will see the status of the network update. Once the network reconfiguration is complete, the UI redirects to the new IP address.

 

Sometimes vCenter will not start after changing DNS servers, and encounter an error message “No healthy upstreams” when connecting with a browser.

We may also encounter the following error message : "Service did not set the task state" 

Here, We can change DNS servers using command line in vCenter.

1. Open a console session of the VCSA, then login with root permission.

2. Run the command:

/opt/vmware/share/vami/vami_config_net

3. Opt for option 4 to change the DNS server.

Main Menu
0) Show Current Configuration (scroll with Shift-PgUp/PgDown)
1) Exit this program
2) Default Gateway
3) Hostname
4) DNS
5) Proxy Server
6) IP Address Allocation for eth0

4. Select option : 4 (DNS)

Note : Keep valid snapshot of the vCenter before proceeding with the changes. If vCenter is in linked mode, need to take offline snapshot of all the vCenters.