/127 between routers?

[Michael Sinatra]

On 1/5/10 7:28 AM, Ken Mix wrote:
> I've also deployed /124s on PTP links to take advantage of the ease of subnetting on a nibble boundary.
>
> Ken
>
>
>> People seem to mostly use /126, /112 or /64 for their p-t-p links.

I have been more conservative and used /96s carved out of a /64 for p2p 
links.  That gives me 32 bits of leeway on either side, allowing me to 
add a couple billion hosts onto my p2p links if I later decide I need 
them or of someone actually does implement subnet anycast.  (Whether 
it's useful or not, someone may decide to implement it or implement 
something that uses it and break your /127s.)  I have used /112s and 
/120s in the past with no problems.  /96 is nice in that it's an easy 
and symmetrical boundary to use.

However, I do agree that there is a lot of waste in using /96s, as it 
affords me "only" 4.3 billion p2ps in a single /64.

Remember, we're going to destroy Internet routing as we know it well 
before we run out of IPv6 addresses.  When we need a new IP after IPv6, 
it won't be because of address exhaustion.

michael