[arin-discuss] Trying to Understand IPV6

[Owen DeLong]

> 
> 
> Just stick to /48 for everyone, and make your projections on that basis.
> You are not wasting anything because /48 per endsite is the design spec
> for IPv6. ISPs should not be trying to reinvent IPv6, just deploy it as
> it is, get your /32 and design your addressing plan based on a /48 per
> endsite. Internal addressing is a bit more complex, but it is worthwhile
> to start by assigning a/48 to each of your endsites and projected endsites
> and only aggregate if really needed.


I am constantly dismayed by this advice.

In the alternative I would recommend the following:

1.	Design your addressing plan based on a /48 per end site.
	An end site is a single structure, or, in the case of a multi-tenant
	structure, a single tenant in that structure.

2.	Figure out how many /48s you need in your largest POP.
	(Ideally, round up to a nibble boundary, but, there is not RIR
	policy to support this (yet)).

3.	Figure out how many POPs you are likely to have in ~5 years.
	(Ideally you'd round this up to a nibble boundary as well, but,
	again, RIR policy needs to catch up on this one, it's not quite
	there yet).

4.	The number of bits required for those two things gives you the
	total number of bits required to describe your network.


So, for example, if you need 8 bits to describe <=256 POPs
and 12 bits to describe <=4096 end sites per POP, you
need 20 bits to describe your network. 48-20 is 28.
You would need a /28.

Once you have done this calculation, then you should apply for
the address space your design requires rather than merely
going in blind for a /32. However, if you require less than a /32,
then, you should get a /32 minimum allocation.

Owen