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

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, an IP address was used as a system name, it is recommended to update the PNID to FQDN first before changing the IP address.
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 server has the correct host records for the vCenter and is included in both forward and reverse lookup zone.

Resolution

Changing the DNS server using the VCSA VAMI

Login into the vCenter's VAMI page via root

https://appliance-ip-address-or-FQDN:5480
On the left hand side panel, navigate to the Networking section.
In the Network Settings view, click on EDIT in the top right corner.
The Edit Network Settings window will appear.
On the Select Network Adapter section, select the NIC to make changes to and click NEXT.
On the Edit settings section, expand the "Hostname and DNS" field and make the appropriate changes and click NEXT.
On the SSO credentials section, enter in the appropriate credentials e.g.: administrator@vsphere.local
On the Ready to complete section, review the settings and accept the acknowledgment.

"I acknowledge that I have made a backup of my vCenter Server and unregistered extensions before continuing with my network configuration"
Next Steps
After network settings have been reconfigured and your vCenter Server Appliance is up and running, additional actions will be required.

All deployed plug-ins will need to be re-registered.

All custom certificates will need to be regenerated.

vCenter HA will need to be reconfigured.

Hybrid Link with Cloud vCenter server has to be recreated.

Active Directory will need to be rejoined.

Note: The additional actions are primarily noted for when performing significant network changes such as changing the FQDN and IP.
Click FINISH
A window will appear with "Network update in progress" "Modifying Network Configuration.
Upon completion, the window will state "Network update succeeded" "Process Completed."

Additional Information

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

Another error message may appear as: "Service did not set the task state"

As an alternative to updating the DNS via the VAMI, it can be changed via command line.

Current Solution:

Changing the DNS server using DCLI:

Open a console to the VCSA, then login with root
If the appliance shell is active and default then continue to Step 4, otherwise move to Step 3
If bash shell is the active and default, access the appliance shell by entering: appliancesh
Once the appliance shell has been accessed, the following command can be run to display the current settings:

dcli com vmware appliance networking dns servers get(Note: The administrator@vsphere.local credentials will be required when the command prompts for username and password)
In order to update the settings, the following command syntax can be utilized:

dcli com vmware appliance networking dns servers set --mode is_static --servers x.x.x.x --servers x.x.x.x(Note: To enter multiple entries, the --server flag must be attached multiple times. Running the command again will just overwrite the existing values)

Legacy Solution:

Changing the DNS server using the VAMI_CONFIG_NET

Open a console session of the VCSA, then login with root.
Run the following command:

/opt/vmware/share/vami/vami_config_net
Enter for option 4 to update the DNS entries

Example

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

Note: Take appropriate snapshots of the vCenter before proceeding with the changes. If the vCenter is in Enhanced Linked Mode, take offline snapshot of all the vCenters.