[ntp:questions] What to do about broken IPv6 sites

Rob nomail at example.com
Tue Jun 23 16:23:04 UTC 2009

Rick Jones <rick.jones2 at hp.com> wrote:
> Allen Kistler <ackistler at oohay.moc> wrote:
>> For example, http://www.ntp.org.
>> NTP.org has a perfectly good IPv4 site, but the IPv6 site doesn't
>> answer to SYNs.  I have no problem with other IPv6 sites, but maybe
>> I'll find some in the future.
>> Since RFC-compliant behavior is to try the IPv6 address first, I
>> have to timeout on every page element before switching to IPv4.
>> I was wondering what the options are to deal with the situation.  I
>> don't have control of the ntp.org DNS domain (or any other broken
>> domains I might find).  Keeping a list in iptables for special
>> behaviors for specific IPv6 addresses really isn't attractive.
>> As more sites put up IPv6 versions, I expect there to be a lot of
>> brokenness that won't be a high priority to fix as long as 99% of
>> everybody is still on IPv4.  What's the most manageable way to deal
>> with this?
> I don't know about the general question, but there are likely folks in
> comp.protocols.time.ntp who know about the www.ntp.org site and its
> IPv6 status, so lets redirect the specific issue there. (I've set the
> Followup-to: header on this post to that end)

I know that it is not what the RFC says, but I think that when you
want usable dual-stack behaviour you need to give IPv4 preference
for now (use IPv6 only when no IPv4 record is available or connection

Of course, when you like to be waiting all the time, try IPv6 first!

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