[126217] in North American Network Operators' Group
Re: DNS for RFC3180 GLOP reverse zone ?
daemon@ATHENA.MIT.EDU (Marshall Eubanks)
Fri May 7 10:36:42 2010
From: Marshall Eubanks <tme@americafree.tv>
To: James Hess <mysidia@gmail.com>
In-Reply-To: <k2o6eb799ab1005062014m3881c6e9ufbe097bb444d7826@mail.gmail.com>
Date: Fri, 7 May 2010 10:35:58 -0400
Cc: "L. Gabriel Somlo" <gsomlo@gmail.com>, nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On May 6, 2010, at 11:14 PM, James Hess wrote:
> On Thu, May 6, 2010 at 1:12 PM, L. Gabriel Somlo <gsomlo@gmail.com>
> wrote: ..
>> I wonder if DNS for GLOP/RFC3180 is still expected to work/be
>> supported,
>> or should I just give up :) > Thanks,
>
> I am not sure, but I believe as a best practice, RFC3180 is
> considered basically defunct at this point, it's obvious that at least
> the RDNS is neglected. The problem is that it relied on mapping bits
> from the AS number into the IP address bitspace.
>
> Now that AS numbers have been extended to 4 bytes in length, and RIRs
> are even about to stop differentiating between them when allocating
> AS numbers, or allowing anyone to request and be sure of getting a new
> 16-bit ASN.
>
> It seems that it will be impossible for the scheme to be followed in
> IPv4.
> A more sensible BCP at this point would be to designate the entire
> 223/8 to IRRs, like was suggested by the BCP for 64512 -- 65535,
> since most ASNs are not using GLOP addressing.
>
Look at RFC 5771
While it is no longer automatic, entities with 4 byte ASN can get
multicast addresses from the
AD-HOC Block III (the old extended GLOP space).
Regards
Marshall
> Mapping ASN bits onto multicast IP ranges is convenient but wasteful
> too, once you consider >2^16 ASNs.
>
> --
> -J
>
>
