The exhaustion of IPv4 address space

FireFury03 writes "Cisco has an interesting article talking about estimates for the exhaustion of the IPv4 address space, and the inevitable move to IPv6. It predicts that the IPv4 address space will be exhausted in 2 - 10 years and suggests that it isn't worth trying to reclaim old allocations. With the mainstream use of IPv6 now potentially within the ROI period of many products the manufacturers need to start including support, but will the ISPs roll out native IPv6 networks before they absolutely have to? IMHO, ISPs providing native IPv6 support would be a Good Thing since it opens up the door for peer-to-peer technologies such as SIP without needing nasty NAT traversal hacks, but a major stumbling block seems to be a complete lack of IPv6 support on current consumer-grade DSL routers (tunneling over IPv4 is an option but requires more technical know-how from the end user)." Of course, Cisco may have some vested interest in driving up the IPv6-compatible router sales *cough*, but the bottom line is that the transition will have to happen at some point in the near future.

Comments

I can't understand why...

[saskboy]

Why don't more routers that are sold today tout their IPv6 compatibility? Are they not compatible with the new protocol? If not why not?

NATs at home can only hold IPv4 together for so much longer. Soon a killer ap will come out that just doesn't want to be NATted, and the whole Internet using public will demand direct addressing [at least they'll demand a solution that requires direct IP addressing].

Is NAT Better?

[HugePedlar]

I remember reading a while ago that NAT actually turned out to be better than IPv6 by virtue of it "solving" the limited number of addresses problem and simultaneously providing a defence against simple hacking attempts by hiding your real IP address.

Can anyone explain whether this is true or not and why?

Re:Is NAT Better?

[fyonn]

I remember reading a while ago that NAT actually turned out to be better than IPv6 by virtue of it "solving" the limited number of addresses problem and simultaneously providing a defence against simple hacking attempts by hiding your real IP address.

well, it's not "better" as such, just a different solution. NAT is not a golden bullet though. Yes, it does, by and large prevent random machines on the internet directly contacting your unpatched windows desktop at home, but a firewall will do that too, and virtually every dsl router has a firewall these days too. I would like to see home dsl routers supporting native ipv6 but I don't know of any.

I think that ipv6 is a good thing to go for, but it's not finished (but then, is ipv4? :). there's lots of advertised features for ipv6 (mandatory encryption, mobile ip etc) that are good on paper, but aren't all that in the real world.

Mandatory support for ipsec is great.. except how many of us would use it? as there is currently no support for mndatory ipsec encryption to unknown strangers. you've got to be pre-configured for crypto. I'd like to see something like ssh. if you know the key then great, if you don't then you can accept and save one and then while you may not have verified the destination, you're at least protected on the wire. yes, they also need to sort out authentication and perhaps some form of certificate distribution, but lets make a start on something useable.

mobile IP. sounds great! I can be using my ipv6 pda via my mobile phone and as I walk into my house, it picks up my wireless net and my downloads speed up instantly, all the while not dropping the voip call I'm making. or I'm using a laptop on the train and as it flits from hotspot to hotspot I don't lose any of my connections. sounds great! how does it work? you tell me, details are not easy to find. ots of talk, few working implementations (if I'm wrong, please tell me, I'm genuinely very interested).

working with networks as part of my job, I know how useful and really annoying NAT can be, and I really think it should be an option, not a requirement. I'd love to see ipv6 rolled out and see what changes it brings, but I also think it needs a fair amount of work still.

dave

Re:Is NAT Better?

[FireFury03]

I remember reading a while ago that NAT actually turned out to be better than IPv6 by virtue of it "solving" the limited number of addresses problem and simultaneously providing a defence against simple hacking attempts by hiding your real IP address.

NAT in itself doesn't provide any extra security - the connection tracking needed by NAT is what provides the security (and you can do this equally well without using NAT). I wrote an article on this subject a while back.

Whiles NAT does to some extent "solve" the limited number of addresses problem, it also creates many more problems. The Internet was designed to be peer to peer but NAT turns it into a client/server model. Whilest client/server works fine for "traditional" applications such as web surfing, it's a major stumbling block for peer to peer services such as VoIP, which have to employ various hacks to trick NATs into letting the peer-to-peer traffic through (with varying degrees of success). The likes of Skype are designed to hijack the connections of random Skype users who don't have NAT and use them to route traffic between peers who do have NAT when the NAT traversal hacks fail.

Re:Is NAT Better?

[Frank T. Lofaro Jr.]

IP address exhaustion is like Peak Oil.

There is a time where the problem is looming, but taking action then will mitigate a lot of the damage.

Or one can wait until it is having severe impacts, and then we will all be hosed very very badly.

for anyone who can't tell wtf is going on

[s388]

TFA didn't help me get much of a clue. I tried reading it, and I said to myself: "aren't there one trillion possible IP addresses, available in principle? (minus 1)" just because of the 12-digit IP addresses i'm used to.

"The IPv4 address space has 32 bits, limiting it to an absolute maximum of 232 (roughly 4.3 billion) possible addresses. For both administrative and technical reasons (the latter in large part being related to routing), IPv4 addresses are allocated in blocks which are restricted to sizes which are powers of 2; this leads to many addresses being unused at any given time. In addition to this, substantial parts of the IP address space are not easily usable because of early technical decisions reserving them for private network use, loopback addresses, multicast, and unspecified future uses, which has resulted in some of these limitations being programmed into devices; working around these limitations will require substantial amounts of re-engineering to increase the amount of available address space. Finally, some of the IPv4 address allocations made early in the development of the Internet (in the 1970s), when only blocks of 224 possible addresses (called a /8 in IPv4 address terminology) were supported, led to some institutions that were involved in the development of the Internet having disproportionally large allocations. MIT, for example, has an entire /8 block allocated to it (224 addresses, about 0.39% of the whole internet address space) and various US Department of Defense agencies have several such blocks."

THANK YOU wikipedia.

Home routers

[bozojoe]

Perhaps this is an AskSlashdot, but who is making a decent(affordable) IPv6 router for the home? And where can one locate documents on SIP/RTP in IPv6 land?

Re:Interesting

[rubycodez]

yup, 8 years ago they were saying the ip4 space would be exhausted in next 5 years. Heck, I sat at a presentation on IPng in 1994 where that was said. At least such a statement is more true now than it was then, but I'll bet reclaiming old absurdly huge allocations of IP space could push this out beyond 10-12 years.

My cold, dead hands

[BJZQ8]

Until I absolutely HAVE to switch to IPV6, I will keep my much easier-to-remember addresses. Try to remember something like these:

fe80::02d0:c1ff:fe5c:0010/10

2002:c0a8:1122::5efe:0a01:0101/48

2001:7f8:2:c01f::2

I mean, DNS goes a long way towards turning that hex into something memorable, but as a sysadmin it does NOT make my life easier. Let's reclaim some of those /8 blocks allocated to people that barely use them, first. Does E.I duPont REALLY need 0.39% of the internet address space? Does Eli Lily? That is 16777216 addresses, for what? Does Eli Lily even have 16 million adressable devices? It seems to me that we have plenty of IPV4's, it's just the allocation stinks.

Re:Already rolled...

[Spetiam]

All I know is that if, once my broadband ISP serves up IPv6, they want to charge me extra for a static IP, I'll be pissed.

Network Operators thoughts on IPv6

[br00tus]

I went to a NANOG meeting in 1997, at which were many of the bigshots of network operation - Van Jacobsen (author of traceroute and Van Jacobsen compression, which you may recall as a checkable option on Windows 3.x's Trumpet Winsock), Paul Vixie (of BIND and MAPS fame), Kim Hubbard (of ARIN), Mark Kosters (of Network Solutions) and that type.

Anyhow, I myself was curious about if/when IPv6 would be rolled out. One of the talks was about how to deal with IPv4 space running out, and a lot of the talk revolved around such things as multiple web sites running on the same IP (which was very uncommon then) and other ways to use less address space. Some audience members gave other suggestions for conserving IP space such as ways to use Network Address Translation to limit public IP use. I would say the feeling in the hall was that this was not a problem, and that people had to go the route of IP sharing, and aside from the need for more IP sharing, everyone pretty much liked the situation as it was, which was in contrast to the prevailing attitude in the world outside the hall. One audience member rose his hand and said, "What about IPv6?" The response to this was the entire audience broke into laughter - it was the funniest thing they had heard that week. After that I began thinking about IPv6 more along the lines of projects such as MBONE (anyone remember the hooplah over that years ago?). Not that IPv6 will never be implemented, but this story that IPv6 was needed straightaway could have been written 8 years ago. I haven't seen much headway in it in the past 8 years, except for products promising they were IPv6 compatible, just in case. Not that IPv6 will never be rolled out on a large scale, but I'm not holding my breath.

Re:Already rolled...

[comcn]

Try Andrews and Arnold. I've had IPv6 (via a tunnel from their network) for the last two years with them. Native IPv6 (without a tunnel) is integrated into the new router they are developing, and should be live by the end of the year (only problem is finding an ADSL router that will support it, but you can use an ADSL modem and Linux, for example).

Re:Interesting

[Hizonner]

Yeah, they said the address space would be exhausted AND THEY WERE RIGHT. The only reason we're not out of addresses now is that people made a fundamental change in the network architecture by deploying NAT (primarily because IPv6/IPng wasn't ready), and using RFC1918 private addresses. NAT is a nasty kludge that breaks all kinds of things. Furthermore, NAT has been done, so it's not going to save us again.

For *business* customers maybe, for a price.

[Bob_Robertson]

I recently asked my cable ISP what their IPv6 gateway was. They said, "We don't provide that service. Maybe you should upgrade to a business account."

They only offer multiple client services on business accounts, so technically I'm already in violation of their rules because of using a router and NAT even though I run no "server", just a couple of PCs.

Yes, Cisco has a vested interest in replacing all those legacy IPv4-only cigar-box routers like mine. Yes, my IP provider would love a reason to raise rates or otherwise push me into a "business" account (and thereby charge me more).

Fact is, I won't be buying a new router, I'll just recycle one PC into place as a gateway and continue to hide behind NAT because I don't care to pay business rates for home PC use.

No matter how much I dislike IPv6 because of its "second system" bloat, I have yet to find a free IPv6 tunnel provider. Yes, it's my fault, people tell me they're out there I just cannot find them.

Bob-

Re:Interesting

[AuMatar]

But no buisness will ever implement a v6 address when v4 users can then not access them. It would incredibly stupid. Thats why we can't just stop handing out v4 addresses.

Its not like there aren't plenty to go around still- HP owns 2 class As now, and a handul of universities own a full A as well. Reclaim a major portion of them for reuse.