An Update to Happy Eyeballs

Document Type Replaced Internet-Draft (individual)
Authors Tommy Pauly  , David Schinazi 
Last updated 2017-03-12
Replaced by RFC 8305
Stream (None)
Intended RFC status (None)
Expired & archived
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IESG IESG state Replaced by draft-ietf-v6ops-rfc6555bis
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


"Happy Eyeballs" (RFC6555) is the name for a technique of reducing user-visible delays on dual-stack hosts. Since one address family (IPv4 or IPv6) may be blocked, broken, or sub-optimal on a network, clients that attempt connections for both address families in parallel have a higher chance of establishing a connection sooner. Now that this approach has been deployed at scale and measured for several years, the algorithm specification can be refined to improve its reliability and generalization.


Tommy Pauly (
David Schinazi (

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