[erlang-questions] : Broken ipv6 behavior?
Thu Apr 17 10:18:06 CEST 2008
On Thu, Apr 17, 2008 at 1:03 AM, Raimo Niskanen
> That patch uses gethostbyname2, which is just as or even more obsoleted
> than getipnodebyname. I wonder when I (finally) have added
> getaddrinfo support if there is need for gethostbyname2 support too?
I tested that patch because the author suggested it worked for him on
Linux, and it's a relatively non-intrusive change. (I don't
particularly care what functions are used for IPv6 support as long as
> It is strange getipnodebyname works so differently from gethostbyname2
> on OS X. They should do the same job.
> The flags to getipnodebyname
> are (AF_V4MAPPED | AI_ADDRINFO), which means that it should return
> mapped v4 addresses only if no IPv6 addresses are found and
> that it should return IPv6 addresses only if the machine runs
> IPv6 ("Only if IPv6 configured" according to Solaris 10 headers,
> "Only if there is an interface on the host that is not a loopback
> interface that has an IPv6 address" according to Steven's
> Unix Network Programming).
On OS X, AI_DEFAULT is defined to (AI_V4MAPPED_CFG | AI_ADDRCONFIG).
I tested various a few different flags options, and ipv6.google.com
would only resolve when AI_V4MAPPED(_CFG) was *not* set. 0 and
AI_ADDRCONFIG both returned an IPv6 hostent structure.
> So maybe gethostbyname2 returns IPv6 records even though your
> machine has no external IPv6 interface?
No, every test I have run regarding Erlang and IPv6 in this thread has
involved a machine with a globally routable IPv6 address configured.
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