Proposed change in 6bone pTLA 3FFE usage - 2nd (final?) version

[bmanning@ISI.EDU]

Note that this change affects the existant documents that are being
used by the various RIR's on their delegation policies, i.e.
RFC 2450,
RFC 2471,
draft-ietf-ipngwg-iana-tla-01.txt
which appears to conflict with RFC 1897.

	I think that this change, as implemented in the 6bone should
	be incorporated by the various RIRs in their operational documents
	and be used as a reference by the IANA in their discussions 
	about longer term delegation policies.  
	Yes, there is a movement afoot to get real bit level delegation
	deployed in the DNS but I don't think we can wait for that.
	

> 
> 6bone Folk,
> 
> I recently proposed changing the pTLA 3FFE:/16 usage to allow future growth as the 6bone becomes used more for production. The current usage specifices an 8-bit pTLA (prefix 3FFE:xx00::/24), thus only providing for 256 pTLAs, of which 57 are currently in use. 
> 
> The proposed change was to leave the lower half of the space usage as is (at least for now):
> 
> 	3FFE:0000::/24 thru 3FFE:7F00::/24  old 8-bit pTLA space
> 
> and starting at this point change to a 13-bit pTLA:
> 
> 	3FFE:8000::/29 thru 3FFE:FFF8::/29  new 13-bit pTLA space
> 
> Also, concern had been expressed about the odd bit size of the /29 in terms of implementing the reverse DNS path, so there was the possibility of making the new space fall on an nibble bit size boundary, say a /28 or /32.
> 
> 
> Comments generally seem to favor setting the new pTLA space at /28 on the grounds that 2048 pTLAs (half of a 12-bit pTLA space) is big enough, and that it makes the reverse path easier to specify for now. There was also a comment requesting that we don't require 8-bit pTLAs to convert to the newer pTLA space. 
> 
> 
> Thus I would like to change the proposal as follows.
> 
> The old 8-bit pTLA space will be reduced to use of the lower half of the space:
> 
> 	3FFE:0000::/24 thru 3FFE:7F00::/24  old 8-bit pTLA space
> 
> and starting at this point change to a 12-bit pTLA:
> 
> 	3FFE:8000::/28 thru 3FFE:FFF0::/28  new 12-bit pTLA space
> 
> I would also like to leave existing 8-bit pTLAs in place for the indefinite future. This issue can be reconsidered in the future as usage of the new 12-bit space dictates. 
> 
> It should also be noted that there is no planned policy at this time for requiring pTLA holders that acquire a TLA or sub-TLA allocation to renumber out of their pTLA. This issue can also be reconsidered in the future as usage of the new 12-bit space dictates. 
> 
> 
> I would like to cease the allocation of /24 8-bit pTLAs at this time, and move to the new /28 space. Hearing no convincing arguments to the contrary, I will assign the next pTLA as a /28. As there are no outstanding pTLA requests in the queue, it makes at least a two week delay in implementing this. Comments to the list please.
> 
> 
> Thanks,
> 
> Bob
> 
> 
> 


-- 
--bill