[arin-ppml] Draft Policy 2009-1: TransferPolicy (UsingtheEmergencyPDP)
Matthew Kaufman
matthew at matthew.at
Thu Mar 26 16:55:53 EDT 2009
michael.dillon at bt.com wrote:
>
> Then you are not looking very far, or more likely, you are not a network
> technical person and therefore feel no need to keep up to date on the
> details of the technology. For at least ten years now we have had
> interworking mechanisms that allow IPv6 networks to access the IPv4
> Internet and vice versa. New ones are coming along all the time such as
> 6VPE. There are no magic bullets, but there are many ways of making
> interworking function well enough to keep a network operator growing and
> profitable.
>
>
I am very much a "network technical person", but that is hardly relevant
to the discussion.
There are interworking mechanisms under development, a few deployed,
which allow IPv6-only hosts to access services that are exclusively on
the IPv4 Internet. Because dual-stack was originally the primary
solution to this problem, the early approaches are few and far between,
though development has sped up significantly across several (probably
too many) IETF WGs. But as previous posters have pointed out, IPv6 was
very clearly not designed for interoperation with IPv4... instead it was
designed as an all new Internet protocol, and sold on many features
(automatic configuration, IPSEC, etc.) that were interesting enough that
IPv4 got them anyway (and a few that still aren't going to happen, like
ubiquitous worldwide IPv6 multicast), thus reducing the perceived value
of IPv6. Now, of course, we have an emergency... IPv4 addresses will run
out, and dual-stack doesn't solve that problem at all.
All methods that allow an IPv6 host to access the IPv4 address require
somewhere between one IPv4 address at the gateway (e.g., NAT64) and one
IPv4 address per host (dual stack). None work in the case of zero IPv4
addresses available for the deployer of the gateway or host.
I do agree that an existing network operator with IPv4 space at their
disposal will be able to use various techniques to continuing growing.
Some operators (providers to consumer end-users) will have it easier
than others (hosting of services that require unique IP addresses).
New entrants will be at a significant disadvantage in that there will be
no PI space available from any RIR, so they will be limited to either
getting IPv4 space (possibly overloaded via things like port-range
sharing a la SHARA) from their ISP or acquiring IPv4 space either via
the proposed transfer policy or via existing transfer mechanisms (buying
existing holder entities).
>> Where does a hosted service that needs to deploy more servers
>> to serve increased demand from existing IPv4 clients get IPv4
>> addresses from after the runout?
>>
>
> From a 6to4 gateway or from some type of NAT box such as NAT-PT.
>
I don't think that's a viable solution. A service that needs to deploy a
new unique IPv4 address to a host that is expected to be reachable from
the legacy IPv4 Internet isn't going to be able to use a NAT device to
synthesize that new address. Perhaps a NAT device would make it possible
for that host to share an address with an existing host, but only if the
port usage is compatible. (For example, deploying two entirely separate
servers that respond on a well-known port isn't going to work)
> If you don't even know the fundamentals, then why are you in this
> discussion?
>
I know the fundamentals, but even if I did not my opinion for or against
a transfer policy is relevant as a holder of both legacy and ARIN RSA
IPv4 space. Personal attacks are irrelevant, though if you knew my
background regarding network protocol design and deployment and/or my
background in ISP operations you might have just skipped them altogether.
Matthew Kaufman
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