DNS for RFC3180 GLOP reverse zone ?

Marshall Eubanks tme at americafree.tv
Fri May 7 14:35:58 UTC 2010

On May 6, 2010, at 11:14 PM, James Hess wrote:

> On Thu, May 6, 2010 at 1:12 PM, L. Gabriel Somlo <gsomlo at 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).


> Mapping ASN bits onto multicast IP ranges is convenient but wasteful
> too,  once you consider >2^16 ASNs.

> --
> -J

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