[c-nsp] IPv6 subnets for point-to-point links

[Pekka Savola]

On Sat, 7 May 2005 sthaug at nethelp.no wrote:
>>> Is it or is it not safe practice to use /127  instead of the recommended /64
>>> and waste a lot of address? What are people typically using?
>>
>> Don't do it.  If you want to use shorter prefixes, I suggest doing
>> something like /112 or whatever.
>
> Ah, but *why* should you not do it?

RFC 3627 gives some reasons why not.

In particular, subnet-router anycast address on /127 is ambiguous on a 
link with two routers and can lead to serious problems.

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