On Mon, 1 Aug 2011, Kevin Stange wrote: > On 08/01/2011 03:37 PM, Matt Domsch wrote: >> On Mon, Aug 01, 2011 at 02:16:30PM -0500, Kevin Stange wrote: >>> Karabir suggested we start getting together a list of steps that need >>> completion to deliver an IPv6-preferenced or IPv6-only list of mirrors >>> for IPv6-only clients using CentOS. >> >> FWIW, Fedora hasn't had a significant need to IPv6-preferenced of >> IPv6-only mirrors. We do manage preference by ASN, netblocks (IPv4 >> and IPv6), internet2 (and related networks) and country. Fedora does >> have nameservers advertised on AAAA records, as well as A records. >> The inbound web proxies are reachable via both AAAA and A records, so >> MirrorManager does see a client's IPv6 or IPv4 address. >> >> MirrorManager replies to client requests with DNS names. Mirrors may >> themselves advertise a given name with an AAAA or A record. > > The idea would be to provide DNS names we know have AAAA records to > provide better quality of service to a yum client that can't use A > records. Otherwise, it's a lot of poking randomly at hosts until one > with AAAA is found. > > It's also just a good idea at this point to at least build the mirror > infrastructure to be IPv6 capable from end to end so that an IPv6-only > client at least has a shot at finding a mirror at all. The question is: are we optimizing our service for ipv6-only clients, or for ipv6-capable (dual-stack) clients? Returning only a list of v6-capable mirrors to a client will help the case of a v6-only client, but could hurt a v6-capable client. One example problem: what do you do when there are no v6 mirrors in a country (since the mirror system today is country-based)? Do you return v4 mirrors from that country, or v6 mirrors from other countries? Remember that in some countries international bandwidth can be very expensive. I am a big proponent of ipv6 (my mirror has had a v6 address for years). However, running a client v6-only ignores the fact the most of the internet is still v4-only (let alone dual-stack). It's an interesting experiment, but a v6-only client is not very useful on today's internet (and probably won't be for several years). I don't think we should cater much to people who choose to make their own lives difficult. DR -- David Richardson <david.richardson at utah.edu> Center for High Performance Computing at the University of Utah "It's possible to tell your mind what to do only when your mind agrees with you." -- Archie Goodwin, "A Family Affair"