Error observed in the vCenter dnsmasq logs "NODATA-IPv6"

Products

• VMware vSphere ESXi

Issue/Introduction

Error observed in the dnsmasq logs on the vCenter:

<DATE> dnsmasq[2072]: query[AAAA] <ESXI_FQDN> from <DNS> 
<DATE> dnsmasq[2072]: cached <ESXI_FQDN> is NODATA-IPv6

Run nslookup for the host fails/does not return the IPv6 value. 

Environment

VMware vCenter Server 7.x

VMware vCenter Server 8.x

Cause

Unable to get any data from the DNS server for IPv6.

The ESXi host management interface has IPv6 enabled and configured as PREFERRED, however, DNS servers without AAAA(IPV6) records for hostnames.

Resolution

If you see NODATA-IPv6 in the DNS logs:

1. Check whether IPv6 is required in your environment

   • If not required, remove or disable IPv6 configuration on the ESXi host management interface. This ensures all queries and connections rely on IPv4.

2. If IPv6 is required

   • Add an appropriate AAAA record for the host in the authoritative DNS server to support IPv6 resolution.

3. Verify network health

   • Ensure that IPv4 configuration is valid and there are no packet drops contributing to DNS lookup delays.