Hybrid Unicast/Multicast DNS-Based Service Discovery

The information below is for an old version of the document
Document Type Expired Internet-Draft (dnssd WG)
Last updated 2015-05-17 (latest revision 2014-11-13)
Replaces draft-cheshire-dnssd-hybrid
Stream IETF
Intended RFC status (None)
Expired & archived
pdf htmlized bibtex
Stream WG state WG Document
Document shepherd No shepherd assigned
IESG IESG state Expired
Consensus Boilerplate Unknown
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


Performing DNS-Based Service Discovery using purely link-local Multicast DNS enables discovery of services that are on the local link, but not (without some kind of proxy or similar special support) of services that are outside the local link. Using a very large local link with thousands of hosts improves service discovery, but at the cost of large amounts of multicast traffic. Performing DNS-Based Service Discovery using purely Unicast DNS is more efficient, but requires configuration of DNS Update keys on the devices offering the services, which can be onerous for simple devices like printers and network cameras. Hence a compromise is needed, that provides easy service discovery without requiring either large amounts of multicast traffic or onerous configuration.


Stuart Cheshire (cheshire@apple.com)

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