Unable to update DNS Servers using the SDDC Manager

Products

• VMware Cloud Foundation

Issue/Introduction

• Attempting to update, add, or configure DNS Servers (including secondary DNS Servers) using SDDC Manager fails via the GUI or API.

  •  var/log/vmware/vcf/operationsmanager/operationsmanager.log or API output shows the following errors:
    
    com.vmware.vcf.systemconfigurator.error.SystemConfiguratorException: Error occurred while testing DNS server for
    
    Error occurred while testing DNS server for
    
    Exception occurred while validating DNS server <ADDRESS> on <ADDRESS>

  • ... Error occurred while validating details of entities.
    ..
    ... Error occurred while testing DNS Servers

• When attempting to configure a secondary DNS Server via the SDDC Manager GUI, the following error may be encountered:

  • Failed to validate NTP configuration. Validate input specification as new DnsConfiguration to VMware Cloud Foundations.

•  DNS Server IPs are not pingable

Environment

VMware Cloud Foundation 4.x and 5.x

Cause

This is due to the DNS Server IPs being unreachable, or unable to be pinged. This  can also occur if ICMP traffic is disabled in the VCF Environment.

Resolution

Please follow below recommendation:

• Ensure that the DNS Servers are able to be pinged from all objects in VCF Environment "SDDC, vCenter, hosts and other items" via ICMP.
• Ensure network connectivity to the DNS Servers.
• Ensure that ICMP Traffic is allowed in the VCF Environment.