First, if you are starting from a /32 and deciding how to carve it up from
there, you are already approaching the problem backwards.
The correct approach (general broad strokes) is to:
1. Identify your subnetting needs.
A. Infrastructure addressing
B. Internal IT needs within the company
C. Customer network needs (usually best to count the
Infrastructure and Internal IT as n*customers at this point when
rolling this all up into a total number of subnets
needed).
D. Decide on a customer end-site subnet size (unless this
is an exceptional case, /48 is a good number to use)
2. Identify the natural aggregation points in your network.
3. Identify the number of /48s (or whatever other size you decided
in D) needed
in your largest aggregation site. (This should be the sum of
all subordinate
end-user networks as well as any infrastructure networks, etc.
Round that up to a nibble boundary ensuring at least a 25% free
space.
4. Identify the total number of aggregation points at the
hierarchy level identified in (3) above.
5. Round that up to a nibble boundary as well.
6. Make a request for the prefix size determined by taking the
number in 1D (/48) and
subtracting the number of bits identified in (3) and (5). e.g.
your largest aggregation
point serves 50,000 customer end sites and you have 196 such
aggregation points.
Each customer end-site is to receive a /48.
50,000 customer end-sites is 16-bits. To get a 25% min free, we
must round up to 20.
This count includes 2 customer end-sites to support ISP
infrastructure and internal IT
needs, respectively.
196 aggregation points is 8-bits. To get a 25% min free, we
must round up to 12.
48-20=28-12=16 -- This network should request a /16 from their
RIR.
Notes:
This is a severe oversimplification. Obviously more details will be required
and the process must be adapted to each individual ISP's network topology and
other considerations.
Your first several iterations of addressing plan will be wrong. Accept it,
deploy it, and expect to redo it a few times before you're completely happy
with it.
Plan big, deploy small the first few times so that you can learn lessons about
the big plan while the deployments are still small.
Owen
On Feb 20, 2013, at 14:44 , Deric Kwok <deric.kwok2...@gmail.com> wrote:
> Hi all
>
> I am searching information about ipv6 addressallocation for /32
>
> Any experience and advice can be shared
>
> eg: loopback. peer to peer,
>
> Thank you so much
