[arin-ppml] Draft Policy 2011-5: Shared Transition Space for IPv4 Address Extension - IAB comment

[Jimmy Hess]

On Tue, Jun 28, 2011 at 1:43 AM, Joel Jaeggli <joelja at bogus.com> wrote:
> On Jun 27, 2011, at 11:24 PM, Benson Schliesser wrote:
>> On Jun 28, 2011, at 0:25, David Kessens <david.kessens at nsn.com> wrote:
> It's new private scope v4 address space carved out of ipv4 unicast space. by definition it breaks assumptions that existing hosts and applications make about non-rfc-1918 space.
>
[snip]

What assumptions would those be?
The word 'private scope'  doesn't appear anywhere in the proposal.
If allocated it's shared use address space for service providers,
for their internal use,  by defintion that means any organization
meeting the criteria of Internet Service Provider could use space
in the /10 for non-conflicting uses inside their SP network.

That also means IP addresses in the shared range could be exposed
and visible to the service provider's end users. Their visibility
makes the addresses non-private;  specifically, they may appear in
traceroute output,  or  the user's  router might utilize a P2P link over this
"shared" address space, depending on how SPs choose to use the
addresses;  SP customers might be assigned IPs in this range and NAT'ed.

It's not just more special address space for private use.

Actually... the whole original reason for the proposal is it's  not
"special private address space",  to provide that the end user
is not already using it.    Some of the needed uses resemble RFC1918
address space usages,  but it is not a requirement served by private scope
address space.

It's that service providers really need a non-private address space available
that will not conflict with private networks using special address space.

Service providers'  intended use does not require uniqueness,  therefore
many IP addresses in the region will be conserved if one shared
allocation is issued, instead of each service provider needing to come in
and request global address space,  when shared address space would
be adequate.



--
-JH