Re: [GLOBAL-V6]The list of current Issues in IPv6 Policy

[Darrell Root <droot@cisco.com>]

Brian Carpenter wrote:

> I think that it would be very interesting for the IETF discussion if
> you could give a short explanation of this need (in a form that can
> be discussed in public). One of the issues in the IETF debate is that
> not everybody agrees that there is a real need for local addresses.

I had a large lab request some v6 space this week.  Their
current v4 usage is about 1000 RFC1918 subnets, so I planned
to allocate a /52 in v6.

They specifically requested non-internet-routable space.  This lab
does (among other things) high bandwidth testing.  Filling up
gig links and such.  If the lab accidentally gets connected to
the production network, and they generate a 1gig stream
with an internet-routable source address, the stream could
follow the default route and possibly get passed to our ISP
(I call this a "not-so-smartbits incident" ;-)

But if the source is not internet routable (as requested), then our
anti-bogon filters will not allow the stream to hit the Internet.
It still might fill up some pipes in our internal network,
but that's better than causing problems for others.

We have many labs that throw large quantities of packets
around.  Allowing connectivity to and between the labs
within our internal network is useful, but using
non-internet-routable space does provide an added
level of protection for labs that routinely do this sort of testing.

I'm not advocating a particular solution, but that's a
real case where non-internet-routable space was
requested.  Global uniqueness of the local space
is not a requirement for us, although I see the
advantages.  If push comes to shove we can survive
without locals.  It's just an added level of protection.

Darrell Root
Cisco IT-LAN-SJ
droot@cisco.com