Subject: Re: [dnsop] IANA section of draft-andrews-full-service-resolvers-01

From: JINMEI Tatuya / 神明達哉 <[email-masked]>
Date: Wed, 21 Dec 2005 14:56:03 +0900

>>>>> On Tue, 15 Nov 2005 16:05:07 +1100, 
>>>>> Mark Andrews <[email-masked]> said:
 
>> 255.255.255.255.IN-ADDR.ARPA /* IPv4 BROADCAST */
>> 
>> ==> should the whole 255.IN-ADDR.ARPA be covered? should 0.0.0.0 be 
>> covered ? what about site-local v4/v6 multicast addresses?

> 	I was being conservative.  I'll follow w.g. advice on this.

> 	As for general multicast the reverse space for IPv4 multicast is
> 	currently populated.

Mac OS X seems to try resolving 0.0.0.0.in-addr.arpa for some
applications (e.g., in the "w" command).  So, covering 0.0.0.0 is
effective at least in practice.  I personally also think it's
justified according to the sence of RFC3330, which reads:

   0.0.0.0/8 - Addresses in this block refer to source hosts on "this"
   network.  Address 0.0.0.0/32 may be used as a source address for this
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   host on this network; other addresses within 0.0.0.0/8 may be used to
   ^^^^^^^^^^^^^^^^^^^^
   refer to specified hosts on this network [RFC1700, page 4].

I think the semantics is effectively the same as that for 127.0.0.1 (or
127/8):

   127.0.0.0/8 - This block is assigned for use as the Internet host
   loopback address.  A datagram sent by a higher level protocol to an
   address anywhere within this block should loop back inside the host.
   This is ordinarily implemented using only 127.0.0.1/32 for loopback,
   but no addresses within this block should ever appear on any network
   anywhere [RFC1700, page 5].

and the full-service-resolvers draft already covers 127/8.

					JINMEI, Tatuya
					Communication Platform Lab.
					Corporate R&D Center, Toshiba Corp.
					[email-masked]
.
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