Home / Blogs

ARIN Provides Latest Word on Need to Move to IPv6: Will Anyone Heed the Warning? (Does anyone care?)

NetworkWorld is running an article today that talks about the announcement from ARIN (the American Registry for Internet Numbers) of the ARIN Board resolution calling upon ARIN to no longer be “neutral” in the IPv4 vs IPv6 space and instead work to actively encourage migration to IPv6.

For those not aware, ARIN is a non-profit organization that allocates IP addresses within North America and is one of the five Regional Internet Registries that allocate IP addresses on behalf of the Internet Assigned Numbers Authority (IANA).

Think of it this way… let’s say you start a business and want to get an Internet connection where you can run your own web server. You need a public IP address, so you are going to contact an Internet Service Provider (ISP), set up service, get an address, etc., etc. If you are in North America, the public IP address you are going to get will have been allocated to your ISP by ARIN. ARIN, in turn, was given blocks of IP addresses to give out by IANA, who is ultimately responsible for all IP addresses. So it looks something like this:

IANA -> ARIN (and the other RIRs) -> ISPs -> You

(and yes, where I said “ISPs”, there may in fact be multiple levels of ISPs and other intermediary registries giving out addresses - I’m trying to make this simple, okay?)

Until now, ARIN and the other RIRs have generally been fairly neutral in the IPv4 versus IPv6 debate and have not shown a preference in allocation, but this announcement from ARIN shows the first signs of change. It starts with this warning:

The available IPv4 resource pool has now been reduced to the point that ARIN is compelled to advise the Internet community that migration to IPv6 is necessary for any applications that require ongoing availability from ARIN of contiguous IP number resources.

And here is the key part of the Board resolution:

BE IT RESOLVED, that this Board of Trustees hereby advises the Internet community that migration to IPv6 numbering resources is necessary for any applications which require ongoing availability from ARIN of contiguous IP numbering resources; and,

BE IT ORDERED, that this Board of Trustees hereby directs ARIN staff to take any and all measures necessary to assure veracity of applications to ARIN for IPv4 numbering resources; and,

BE IT RESOLVED, that this Board of Trustees hereby requests the ARIN Advisory Council to consider Internet Numbering Resource Policy changes advisable to encourage migration to IPv6 numbering resources where possible.

The net of it is that we can expect that ARIN (and undoubtedly the other RIRs) will make it increasingly harder for ISPs to obtain IPv4 address blocks and will be scrutinizing requests… while it will be basically wide open for IPv6 allocation.

So how long do we have?

If you read Jeff Doyle’s blog (an excellent one on IPv6 issues), he believes that IANA will stop IPv4 allocations in late 2008 or early 2009. Given that RIRs have existing pools of IPv4 addresses to allocate, IPv4 addresses may continue to be available through 2009 or 2010.

2009? 2010?

That’s not that far out, when you think about it. Given that we’ve been talking about IPv6 for now most of 20 years, the date does indeed seem to be looming.

The real question to me, though, is simply this - will anyone care?

Will anyone heed these and the other warnings and start the migration to IPv6? Or will we just keep going along as we are until we hit the real bump in the road and it becomes a crisis?

Were I a betting man, my money would be on the “crisis” scenario.

My previous posts on IPv6
• Ars Technica: “Everything you need to know about IPv6”
• Jeff Doyle: “No Way to Slow Down”, “The IPv6 Business Case”, and “Getting to the Next Generation”
ARIN IPv6 Information Forum
IPv6 Forum

By Dan York, Author and Speaker on Internet technologies - and on staff of Internet Society

Dan is the Director, Online Content, for the Internet Society but opinions posted on CircleID are his own. View more of Dan’s writing and audio here.

Visit Page

Filed Under


John Curran  –  Jun 12, 2007 3:00 PM

Were I a betting man, my money would be on the “crisis” scenario.

So, Dan, what are you going to do about it?


Edward Lewis  –  Jun 15, 2007 5:08 PM

I’ve been thinking of responding to this for some time.

Rhetorically speaking, what is meant by IANA running out of IPv4 addresses?  It means that there are no more “new” (as in “old growth forest”) IPv4 addresses available.  There will be some months of “rolling stock” available at the RIRs and at LIRs.  There will be some addresses available via reclamation and possibly via mergers and acquisitions.  We just won’t find very large contiguous ranges of addresses anymore.

The IPv4 network will continue to function just as nicely as it does now but it won’t be able to grow.  If we play tricks with NAT, we can extend the network further but at an increasing operation expense “per capita.”  There will continue to be a need for the RIRs and IANA to keep track of assignment even if they are no longer assigning new space.

The crisis will only come to play in the growth plans of the network.  Love it or hate it, this is the one thing IPv6 can help with - and this is what ARIN is stating.

One of the greatest problems in IPv6 is the routing impact.  With more addresses there will be more places to go.  It logically follows that it will take more memory to hold all the routes and take longer for the routing system to set up forwarding tables.  These problems are not solved by IPv6 - but do they need to be?  If we just take the IPv4 network we have today and convert it to IPv6, we wind up with the same size network, is routing going to be any worse?

There is little doubt that the current bottleneck to Intenet growth is the diminishing address supply.  It looks like the next bottleneck is routing.  Shifting to IPv6 removes the first bottleneck but does not solve the second.  But, at least IPv6 removes the first and we then have time to solve the second bottleneck.

I think the ARIN board is doing a responsible thing, making the industry aware of the coming exhaustion of new IPv4 addresses.  Operational expense-wise, moving to IPv6 is most likely going to be chearper than trying to extend IPv4 via NAT boxes - just a guess but I’m pretty sure of it.  IPv6 isn’t the greatest thing ever, but it’s not worse than IPv4 and we can grow the network further with IPv6.

Comment Title:

  Notify me of follow-up comments

We encourage you to post comments and engage in discussions that advance this post through relevant opinion, anecdotes, links and data. If you see a comment that you believe is irrelevant or inappropriate, you can report it using the link at the end of each comment. Views expressed in the comments do not represent those of CircleID. For more information on our comment policy, see Codes of Conduct.

CircleID Newsletter The Weekly Wrap

More and more professionals are choosing to publish critical posts on CircleID from all corners of the Internet industry. If you find it hard to keep up daily, consider subscribing to our weekly digest. We will provide you a convenient summary report once a week sent directly to your inbox. It's a quick and easy read.

I make a point of reading CircleID. There is no getting around the utility of knowing what thoughtful people are thinking and saying about our industry.

Co-designer of the TCP/IP Protocols & the Architecture of the Internet



Brand Protection

Sponsored byCSC

IPv4 Markets

Sponsored byIPv4.Global

New TLDs

Sponsored byRadix


Sponsored byVerisign

Threat Intelligence

Sponsored byWhoisXML API


Sponsored byDNIB.com

Domain Names

Sponsored byVerisign