Re: IPv6 address assignment for strictly point-to-point links and Device Loopbacks

Indeed, and I see a sheer wastage in blocking the entire /64 whose one /127 is used on p2p links. 

There are many deployments that already assign bunch of /64 (or lower) prefixes per hierarchy and encode bunch of useful info in 72-96 and then assign thousands of /127s out of each /96 (or encode ipv4 loopbak address in it to get /128 loopback)  to thousand of network infrastructure devices. 

This has pros and cons, but the point is that this should be a deployment choice, not a standard mandate.

Cheers,
Rajiv

Sent from my Phone

On Sep 21, 2012, at 7:06 PM, "Brian E Carpenter" <brian.e.carpenter@gmail.com> wrote:

> On 21/09/2012 22:35, Usman Latif wrote:
>> Thanks Wes for the feedback.
> 
> ...
>>>>> Without this stated clearly there is likely to be some instances where readers interpret it the wrong way and end up assigning multiple p2p links with /127 subnets from a single given /64 and end up having to re-address their network in future when/if future standards use lower order 64 bits for special purposes.
>>> [WEG] Given the fact that there is a standard that documents the use of a /127 for P2P links (6164), 
> 
> Wes, I think that statement is even a bit weak, since 6164 actually says:
> 
> "assuming that a number of point-to-point links will be numbered out of a single /64 prefix:"
> 
> so it is very clear: it is allowed by the standard to share a /64 among
> however many pt2pt links the operator cares to. This is *not* a wrong
> interpretation.
> 
> As you say, any future work will need to take account of this.
> 
>   Brian
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