[arin-ppml] IPv4 is depleted today
David Farmer
farmer at umn.edu
Fri Aug 29 12:33:51 EDT 2008
When will IPv4 be depleted? Well I realized yesterday that for me and many
other Legacy holders it already is.
Let's step back a minute, from discussion on the list its become obvious to
me that IPv4 depletion isn't a singe event like when the IANA or ARIN Free
Pools are depleted, it is not a magic date. It is a series of events or dates
that occurs when each organization can't easily get any more addresses.
For some networks, that date will come before others, and for some that
date could be a long ways away. Then, I realized for some of us that day
already came a long time ago, especially for many Legacy holders.
Actually, for UMN that day was 8 or 10 years ago, when I realized we will
never ever justify another IPv4 address assignment, nor should we for that
matter. I'm not complaining or bragging, but stating a fact. You could argue
that we don't deserve the resources we have and should return some. I'll
grant you the right to your opinion. I have arguments why I believe your
wrong. However, both are irrelevant to this line of thought.
The discussion about what IP addresses cost got me thinking about this.
Because, IP address have been quite expensive for us for sometime, not in
hard currency, but in remembering and reorganizing within the IPv4 address
space we have. This is no where as easy as some on the list try to make it
sound, NATs don't scale for us in bandwidth, number of flows, or cost.
There are a few places we use RFC1918 addresses, mostly for things that
don't ever need to talk to the Public Internet, but DNS issues both for
reverse and the leaking of forward DNS out to the Internet make this very
ugly and just as much of a Hack as NAT. We are considering very limited
uses of NAT, like for visitor wireless access.
Personally, I can't compare these costs to the costs associated with
justifying more address space through ARIN. Realistically we can't do that,
at least not until very long after IANA free pool exhaustion. It is possible that
they are comparable, I don't know.
You might say we (UMN) really have not and probably will not completely
exhaust our IPv4 address, that is use it to 100%, well that is probably true.
But, this is probably going to be true for all networks. There are very few if
any networks that use each and every address they have. There will always
be little unused bits within subnets and small subnets sitting around in all
networks. The difference is only a matter of degree and the rate of growth
for each network. Eventually, each network will get into a dead-lock state
where they don't have enough resources to maneuver to free up old
resource, or a pseudo-dead-lock where it is more costly than it is worth to
free up old resources.
So what will we (UMN) do when the IANA and ARIN IPv4 free pools are
gone? Well, much the same as we are doing now, try to make use of our
current resources more efficiently. We probably will never sell or return our
current IPv4 address space it is to valuable internally. We might share it
with other less directly associated customers or projects, but always public
entities.
What about IPv6 you ask, well we have been working on it for sometime, the
GigaPOP (think of it as an Internet2 regional ISP) we operate has been
doing IPv6 for over 5 years. I my opinion, IPv6 transport is very easy, and
been that way for a while. Where things get much harder is the local subnet
and with the host. We have had IPv6 operating in our lab off and on over
the last 5 years, for about the past year we have had it in Beta on the
network engineers and security folks subnets. I hope to enable it on our
whole backbone and make it available anywhere anyone wants it yet this
year or early next, then in 2010 or 2011 turn it on by default everywhere on
campus.
Personally I think, increased use IPv4 NAT, some kind of transfer policy, or
forced return of unused resources, will be necessary to extend the life of
IPv4 long enough for us to get IPv6 ramped up. I think a transfer policy will
be cleaner than trying to force people to return resources.
But please don't take that as saying I like those options or that it is an
alternative to deploying IPv6, it is just necessary. We have to do BOTH, we
have to keep the IPv4 elephants dancing until we get all the IPv6 elephants
dancing. I loved that pice of metaphoric imagery.:) So, if you haven't
started tuning up the IPv6 band for the IPv6 elephants get started now, the
IPv4 elephants are starting to get tired.
=======================================================
David Farmer Email: farmer at umn.edu
Office of Information Technology
Networking & Telecomunication Services
University of Minnesota Phone: 612-626-0815
2218 University Ave SE Cell: 612-812-9952
Minneapolis, MN 55414-3029 FAX: 612-626-1818
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