Implementing DNS client for support IPv6/IPv4

[sasson, shuki]

Hi all, I have been reading the RFCs related to extending DNS support for IPv6 and I am a bit confused. I understand that there 2 types of RR that may represent IPv6 entries basically AAAA and A6. These entries will be on to of the previous type A. On top of that from the Transition Mechanism RFC a DNS resolver may return only the requested type as an answer. The AAAA RFC states that the all other IPv4/IPv6 address should be returned on the additional information field.    Our host is aiming on Dual Stack implementation, basically we need to implement the following 3 requests:   Give up all the addresses IPv6 or IPv4 for a name. Give us all the IPv4 addresses. Give us all the IPv6 addresses.   My questions are: What QTYPE should I use in order to get all the IPv4 and IPv6 addresses A, AAAA, A6? Is that possible through one query or multiple queries are needed? What QTYPE should I use in order to get all the IPv6 address AAAA or A6? Should we apply two separate queries for A6 and For AAAA? What is the status of A6 since I saw an informational RFC recommending to stay away from implementing A6 RR: ftp://ftp.rfc-editor.org/in-notes/rfc3363.txt   Thanks for your help! Shuki Sasson Principal Engineer, Network Storage Group EMC² where information lives Phone: 508 305 8515  Cell:     617 834 4258 Pager: 877 919 0794 Email: [EMAIL PROTECTED]