VCF Installer Fails SDDC Specification Validation with error "SSH: Failed to establish SSH session to <VCF Installer FQDN> Auth fail"

Products

• VMware SDDC Manager
• VMware Cloud Foundation

Issue/Introduction

• Validating the SDDC specification from the VCF Installer (VCF 9.0.1, Brownfield conversion) failed with the error: "SSH: Failed to establish SSH session to <VCF Installer FQDN>  Auth fail".

• Verification confirmed that there was no issue with DNS resolution for the SDDC/VCF Installer FQDN.

Environment

- Product/Component: VCF Installer
    
- Version: VCF 9.0.1
    
- Deployment Type: VCF Brownfield Conversion

Cause

The issue was identified as an incorrect DNS domain name configuration within the VCF Installer setup. The initial configuration mistakenly used the Fully Qualified Domain Name (FQDN) of an VCF Installer appliance (e.g., <VCF Installer FQDN>) instead of the correct base domain name (e.g.,<DNS Domain Name>).

The log sequence confirmed a name resolution problem: a "Failed to get DNS information" error immediately preceded the "SSH Auth fail" error, indicating the underlying issue was the inability to correctly resolve names due to the configuration error, which then failed the validation step with an SSH authentication-related error.

• The /var/log/vmware/vcf/domainmanager/domainmanager.log confirmed the failure with the following error messages, suggesting a root cause related to name resolution that manifested as an authentication failure:

YYYY-MM-DD T06:33:01.317+0000 ERROR [vcf_dm,6916cd0e6c2f5c7d803fee48712640e9,30fa] [c.v.e.s.c.u.c.SshCommandExecuter,http-nio-127.0.0.1-7200-exec-2] Could not connect to the SSH server @ <VCF Installer FQDN> for configuration.
YYYY-MM-DD T06:33:01.318+0000 ERROR [vcf_dm,6916cd0e6c2f5c7d803fee48712640e9,30fa] [c.v.e.s.v.util.DnsAndNtpUtil,http-nio-127.0.0.1-7200-exec-2] Failed to obtain DNS information from VCF Installer with hostname<VCF Installer FQDN>
YYYY-MM-DD T06:33:01.318+0000 ERROR [vcf_dm,6916cd0e6c2f5c7d803fee48712640e9,30fa] [c.v.v.v.c.v1.VcfInstallerController,http-nio-127.0.0.1-7200-exec-2] Failed to validate SDDC specification.
...

YYYY-MM-DD T06:33:01.321+0000 ERROR [vcf_dm,6916cd0e6c2f5c7d803fee48712640e9,30fa] [c.v.e.s.e.h.LocalizableRuntimeExceptionHandler,http-nio-127.0.0.1-7200-exec-2] [18P48G] FAILED_TO_GET_DNS_INFO Failed to get DNS information
YYYY-MM-DD T06:33:01.323+0000 DEBUG [vcf_dm,6916cd0e6c2f5c7d803fee48712640e9,30fa] [c.v.e.s.e.h.LocalizableRuntimeExceptionHandler,http-nio-127.0.0.1-7200-exec-2] Handler Error Response: {"errorCode":"FAILED_TO_GET_DNS_INFO","arguments":[],"message":"Failed to get DNS information","causes":[{"type":"com.vmware.evo.sddc.common.util.command.CommandExecuterException","message":"SSH: Failed to establish SSH session to <VCF Installer FQDN>"},{"type":"com.jcraft.jsch.JSchException","message":"Auth fail"}],"referenceToken":"18P48G"}

Resolution

To resolve this issue, Need to correct the VCF Installer DNS network configuration with DNS domain name to use the base domain name instead of the FQDN.

• Access the DNS configuration settings for the VCF Installer and locate the field for the DNS domain name and correct the value from the FQDN (e.g., <VCF Installer FQDN>) to the base domain name (e.g., <DNS Domain Name) following the KB - Configure/Update DNS Config on VCF Installer

The configuration changes with the base domain name successfully resolved the validation error, allowing the VCF deployment to proceed.