IPv6 Address Planning

[Pekka Savola]

On Tue, 9 Aug 2005, Sander Steffann wrote:
>> Within these /80's are individual /112's for PTP links.
>
> Why use a /112 for point-to-point links? The only reference I can find is 
> rfc3627, and that one does not really seem to advise to use a /112 except 
> when using a /64 is not possible... So I am curious about why a /112 is used.

FWIW, IMHO there's little difference between a /64 and /112 
_technically_.

We ended up using /112's in our backbone because we wanted to create a 
nice "mapping" mechanism, where we encode the region of the pop, the 
pop itself, and the sequence number of the router in the pop in the 
prefix.  Just by looking at a p2p link prefix, I can see the routers 
which it connects.  As DNS exists for reverse lookups, I don't think 
this is necessary, but we felt this provided some value, so we ended 
up using /112's.

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings