Happy Eyeballs, the IETF draft promising a snappy application connection to the best performing address family whether IPv4 or IPv6 (as well as an organic free-range chicken in every pot and an electric car in every garage) would seem to be, if not a definitive solution to the long-standing “IPv6 brokenness” issue, then at least a great leap forward.
The basic idea is immensely clever* in its disregard for the logic of the prevailing standard of RFC3484 and IPv4 fallback: for an application connecting to a web-based resource, name resolution to IPv4 and IPv6 addresses (as well as any subsequent connections to those addresses) should occur in parallel with the connection to the best performing address persisting while the runner-up is politely ignored or reset as needed. (Also refreshing is the implied presumption that IPv4 can be just as broken as IPv6 might be!).
So far, at least Mac OS X and Chrome have instituted some variant of it and the results are quite impressive (consistent sub-second performance times even with broken IPv6 connectivity). APNIC’s chief scientist Geoff Huston has a humorously-titled analysis (don’t believe me? click here) that digs into what’s going on under the hood. He also discovers some instances where performance suffers to the same degree of poor IPv4 fallback–namely, where a responsive resource address exists among multiple inactive addresses (resulting in more than 75 seconds of transaction latency).
More troubling for the cause of IPv6 adoption is perhaps found in Emile Aben’s (of RIPE) article on the same topic where he discovers that the Mac OS X implementation of “happy eyeballs” leaves available and working IPv6 resources under-preferred in half the tested cases resulting in a condition he dubs “hampering eyeballs.”
As we head into the new year with the promise of another World IPv6 event as well as more users and content than ever before connecting to the Internet via IPv6, “happy eyeballs” looks poised to help solve one outstanding problem while, depending on how it gets implemented, perhaps creating some new ones.
*And as clever as Happy Eyeballs might be, its co-author Andrew Yourtchenko might be at least as well known for this amusing video.
