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Re: [Fwd: Re: About IPv6 private address]
On Feb 5, 2008, at 15:06, bill fumerola wrote:
$ host lurgee.local
Host lurgee.local not found: 3(NXDOMAIN)
This could be regarded as a bug, but it's a tricky case. The /usr/
bin/host command isn't using the system name resolver. It's
distributed with BIND, so it's basically doing the same thing that /
usr/bin/dig is doing. It makes DNS queries only. Multicast DNS is
derived from DNS, but it's not strictly the same as DNS, so /usr/bin/
host doesn't know anything about it.
$ ping -qc 1 lurgee.local 2>&1 | tail +4
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.270/0.270/0.270/0.000 ms
$ uname -
a ~
Darwin worrywort.local 8.11.1 Darwin Kernel Version 8.11.1: Wed Oct
10 18:23:28 PDT 2007; root:xnu-792.25.20~1/RELEASE_I386 i386 i386
At least, the .local domain has a long and ignoble history of not
being usable as a global TLD in the DNS protocol. Apple was already
doing something weird and non-standard with it back in the Mac OS 9
days, when the DNS protocol was young and dinosaurs yet roamed the
Internet, so it's not like they polluted an otherwise pure water
table by repurposing it for Multicast DNS.
Still, IETF does have a problem. There are *two* Multicast DNS
protocols. There is RFC 4795 (informational) for Link-Local
Multicast Name Resolution, which is implemented in Microsoft products
but not much else. And there is <http://tools.ietf.org/html/draft-
cheshire-dnsext-multicastdns>, the Multicast DNS protocol in Bonjour,
which enjoys widespread industry adoption, in multiple
implementations, currently shipping in a myriad of commercial
products, but has been languishing as an under-loved individual
submission to the DNSEXT working group since before the Great Cataclysm.
It would be very nice to have an RFC to which we could point
questioners like the originator of this thread and say to them, "Upon
this rock we have built our church." Sadly, we can't. I don't know
what to do about that. Absent an RFC, I think the best we can do is
to tell such questioners, "Good luck. Write if you get work."
--
james woodyatt <jhw@apple.com>
member of technical staff, communications engineering