Temporary failure in name resolution with an Error on the HCX migration tool: UnknownHostException

Products

• VMware HCX
• VMware Cloud on AWS

Issue/Introduction

Symptoms:
The error on the HCX migration tool: UnknownHostException hcx.sddc-xx-xx-xx-xx.vmwarevmc.com: Temporary failure in name resolution

Resolution

1. Log in to the VMC Console at https://vmc.vmware.com
2. Select the desired SDDC and navigate to the Networking and Security > System > DNS
3. Verify that none of the DNS ie., the primary DNS and the secondary DNS are not pointing to decommissioned DNS servers.
4. Update the SDDC DNS settings if step 3 is negative as follows:

• From the SDDC console, navigate to Networking and Security > System > DNS, click on the Edit option (three dots) next to defaultZone. this will allow the administrator to change the DNS Server 1 and DNS Server 2.
• This change can also be done under the Management Gateway in the same section.
• Below is a figure depicting the same:

5. Now update the on-prem HCX manager DNS Settings:

• Navigate to the url of the format: https://OnPremiseHCXaddress:443
• Navigate to Administrator > Network Settings and update both the DNS servers and the Search domain.

6. Reboot the HCX Manager and test the migration.