VCF Installer Precheck Failure: "Please ensure there are no DNS aliases configured for vCenter FQDN. vCenter IP address must resolve to a single FQDN"

Products

• VMware SDDC Manager / VCF Installer

Issue/Introduction

• The VMware Cloud Foundation (VCF) installer precheck fails during the validation of existing components.
• The installer UI reports the following error: "Please ensure there are no DNS aliases configured for vCenter FQDN. vCenter IP address must resolve to a single FQDN."
• Reverse DNS resolution (PTR record) for the vCenter Server IP address fails when queried via <nslookup> from the vCenter Server Appliance (vCSA) shell or the VCF installer appliance.
• Forward DNS resolution (A record) for the vCenter Server FQDN is successful.

Environment

VMware Cloud Foundation (VCF) 9.x
VMware vCenter Server 9.x

Cause

The precheck validates that the vCenter Server IP address uniquely resolves to its configured FQDN via a reverse DNS lookup. The failure occurs because the configured DNS server is missing the corresponding PTR record for the vCenter Server IP address, or an incorrect DNS server is specified in the appliance network configuration.

Resolution

Validate and correct the DNS configuration as follows to ensure successful reverse resolution:

1. Validate Current Resolution State: Execute the following commands from the vCSA shell and the VCF installer appliance to confirm the absence of the PTR record:
   nslookup <vCenter_Server_IP_Address>
nslookup <vCenter_Server_FQDN>

2. Correct DNS Records: Engage the network or DNS administration team to create the missing PTR record for the vCenter Server IP address on the authoritative DNS server.
   Note: If the infrastructure relies on a specific DNS server for these records, verify that the vCSA and VCF installer are configured to query the correct DNS server IP.

3. Verify Remediation: Once the DNS changes have propagated, repeat the nslookup commands from Step 1. The vCenter Server IP address must return the exact vCenter Server FQDN.

4. Retry Precheck: Return to the VCF installer and re-initiate the precheck workflow. The existing component validation will pass once the PTR query succeeds.