Some thoughts on QDCOUNT

Neither DjbDNS, BIND, nor MSDNS support queries where QDCOUNT > 1. DjbDNS ignores queries where QDCOUNT > 1. Microsoft DNS server replies with a "format error", and the qdcount is set to the number of questions sent to the server. BIND 8 replies with a "format error", and QDCOUNT is set to zero.

Realistically, DNS servers should problably reply with "not implemented" instead of "format error".

Some discussion of the fact that QDCOUNT > 1 queries are not handled by modern-day DNS servers:

http://www.ietf.org/proceedings/98aug/I-D/draft-ietf-dnsind-edns-03.txt
http://www.vpnc.org/ietf-ipsec/96.ipsec/msg00779.html
http://www.wcug.wwu.edu/lists/ipng/200005/msg00080.html

In summary, the nitty gritty implementation details of handling multiple question queries in a single packet make this difficult to correctly handle.

I'm making the handling of multiple QDCOUNT queries a low priority in MaraDNS.