Re: IPv6, multihoming, and customer allocations

[Joel Jaeggli <joelja () bogus com>]

On 03/16/2010 07:38 AM, Rick Ernst wrote:
> Regurgitating the original e-mail for context and follow-up.
>
> General responses (some that didn't make it to the list):
>   - "There really is that much space, don't worry about it."
>   - /48s for those that ask for it is fine, ARIN won't ask unless it's a
> bigger assignment
>   - /52 (or /56) on smaller assignments for conservation if it makes you
> feel better
>   - Open question on whether byte/octet-boundary assignment (/56 vs /52) is
> better for some reason
>
> I haven't seen anything on the general feel for prefix filtering.  I've seen
> discussions from /48 down to /54.  Any feel for what the "standard" (widely
> deployed) IPv6 prefix filter size will be?

I filter at /48. I would consider filtering on something shorter for
assignments of /32 or shorter if there were obvious bad behaver's. We do
advertise more specific /36s but we also have the covering /32.

> Thanks,
>
>
> On Sat, Mar 13, 2010 at 10:49 PM, Rick Ernst <nanog () shreddedmail com> wrote:
>
> > A couple of different incantations searching the archive didn't enlighten
> > me, and I find it hard to believe this hasn't been discussed.  Apologies and
> > a request for pointers if I'm rehashing an old question.
> >
> > As a small/regional ISP, we got our /32 assigned and it's time to start
> > moving forward (customers are asking for it).  New hardware, updated IOS,
> > etc. are in the pipe.  Discussions are beginning with our upstream providers
> > for peering.  Now, what do we do?
> >
> > A /48 seems to be the standard end-user/multi-homed customer allocation and
> > is the minimum allocation size from ARIN.  A /32 provides 65K /48s so, in
> > theory, we could give each of our customers a /48 and still have room for
> > growth.  A /48 also appears to be generally accepted as the the longest
> > prefix allowed through filters (although /49 through /54 are also
> > discussed).  Most customers, however, won't be multi-homed.
> >
> > Partly from an IPv4 scarcity perspective, and partly from general
> > efficiency and thrift, it seems awfully silly to hand out /48s to somebody
> > that may have a handful of servers or a couple of home machines, especially
> > with special addressing like link-local if the hosts are not expected to be
> > internet reachable (back-end servervs, etc).
> >
> > Based on the above, I'm looking to establish some initial policies to save
> > grief in the future:
> > - /52 allocations to end-users (residential, soho, etc.)
> > - /48 allocations to those that request it
> > - If you are going to multi-home, get your own space
> >
> > This is obviously a very broad brush and takes an insanely large addressing
> > model and makes it even larger (assigning /52s instead of /48s) but, to me
> > at least, it seems reasonable for a first-pass.
> >
> >  For context/scope, we currently have the equivalent of a bit more than the
> > equivalent of a  /16 (IPv4) in use.
> >
> > Thanks,