[ntp:questions] Pool returns IPv6 address to IPv4 query

Rick Jones rick.jones2 at hp.com
Tue Nov 19 19:47:06 UTC 2013

Brian Utterback <brian.utterback at oracle.com> wrote:
> On 11/19/2013 12:33 PM, Rick Jones wrote:

> > Later, when interfaces started getting auto-configured, local
> > scope IPv6 addresses, there was a call to change that to be "don't
> > return IPv6 addresses unless there is a better-than-local-scope
> > IPv6 address assigned."  Started causing me all manner of pain in
> > netperf :( Not sure where that stands now in the Linux world.
> >
> > rick jones

> Yes, that was the issue. Further complicating it was what do you
> return if you have no IPv6 interfaces and you set AI_ADDRCONFIG and
> you pass in a literal IPv6 address.  The problem is that getaddrinfo
> replaces both gethostbyname and inet_aton, each of which you might
> expect to have different results in that case. We had people citing
> two RFC's and the ipng working group mailing list. Great fun.

That passing-in a literal IPv6 address is precisely where I first
started noticing problems with netperf.  For ages (in Internet Time at
least) it "just worked" even when all I had were local-scope
(link-scope?) IPv6 addresses configured.  Then someone made a libc
change and life became Quite Unpleasant (tm).

rick jones
I don't interest myself in "why." I think more often in terms of
"when," sometimes "where;" always "how much."  - Joubert
these opinions are mine, all mine; HP might not want them anyway... :)
feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH...

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