Re: IP4 Space

[Owen DeLong <owen () delong com>]

On Mar 6, 2010, at 1:37 AM, Thomas Magill wrote:

> > That brings a question to mind.  As an ISP, with IPv4, end sites that
> > are multihoming can justify a /24 from us (or another upstream) and
> > announce it through multiple providers.  With IPv6, are they supposed
> to
> > get their block from ARIN directly if they are multihoming?  In other
> > words, should I _never_ allow customers to announce smaller blocks of
> my
> > IPv6 ARIN block?
>
> According to ARIN, you must meet their IPv4 requirements for an ARIN
> block to get an IPv6 ARIN block.  That leads me to believe that the same
> customers who need v4 space from you would also need v6 space from you.

Um, not exactly.

According to ARIN, _IF_ you meet their requirements for obtaining an IPv4
block, then, you ALSO automatically meet their requirements for obtaining
an IPv6 block.

There are ALSO other ways to qualify for an IPv6 block, completely independent
of the qualification for or possession of an IPv4 block.

As to the question about what you should or should not allow your customers
to announce, that is up to you.

However, there is a specific block being used to issue ARIN end-user
assignments, and, many ISPs filter that more liberally (/48) than they
filter blocks used for allocation (/32).  As such, your customers who are
multihomed _MAY_ have a better chance of having their prefix seen if
they use an ARIN direct assignment.

However, there is at least 1 provider (hello, AS701) that blocks nearly
all prefixes longer than /32 in IPv6, so, customers that are multihomed
and announcing a more specific from your space would appear as
if they are single-homed to Verizon customers, while they would
be invisible to Verizon customers if they use ARIN space.

There may be other providers with similar filtration policies. 

Hurricane Electric will accept routes either way. I cannot speak in
detail about the conduct of other providers, as I do not know their
policies.

Owen