Skip to main content

The DISCOVER opcode

Document Type Expired Internet-Draft (dnsext WG)
Expired & archived
Authors Bill Manning , Paul A. Vixie
Last updated 2015-10-14 (Latest revision 2003-10-14)
RFC stream Internet Engineering Task Force (IETF)
Intended RFC status Experimental
Additional resources Mailing list discussion
Stream WG state WG Document
Document shepherd (None)
IESG IESG state Expired (IESG: Dead)
Action Holders
Consensus boilerplate Unknown
Telechat date (None)
Responsible AD Dr. Thomas Narten
IESG note Waiting for -02 to appear, with responses to WG comments.
Send notices to <>

This Internet-Draft is no longer active. A copy of the expired Internet-Draft is available in these formats:


The QUERY opcode in the DNS is designed for unicast. With the development of multicast capabilities in the DNS, it is desireable to have a more robust opcode for server interactions since a single request may result in replies from multiple responders. So DISCOVER is defined to deal with replies from multiple responders. As such, this document extend the core DNS specifications to allow clients to have a method for coping with replies from multiple responders. Use of this new opcode may facilitate DNS operations in modern networking topologies. A prototype of the DISCOVER opcode was developed as part of the TBDS project, funded under DARPA grant F30602-99-1-0523.


Bill Manning
Paul A. Vixie

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)