While troubleshooting another issue on my Windows 2008 R2 domain controller I noticed that in my wireshark capture there are packets from my ESXi 4.1 U2 hosts for DNS queries using IPv6 (they show up as "Standard query AAAA <domain controller FQDN>+domain again (e.g. mydc.mydomain.com.mydomain.com)". After this query comes back unsuccessfully I see a packet that is the normal IPv4 "Standard query A <domain controller FQDN>" which resolves successfully.
The hosts are registered in AD. I checked my ESXi hosts and have IPv6 disabled on all hosts. Why would my hosts be doing these lookups?
Thanks.