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• There are several mechanisms for running IPv4 and IPv6 side by side, and that was a major part of the discussion in the IPv6 rollout early on. Medium sized chunks of the net were running IPv6 for quite a while, and were routed in and out of fairly seamlessly. transition mechanisms were designed, long before IPv6 was adopted by the IETF. (the linked RFC is from 1995).
• IPv6 designers also put in tools designed to provide for mobile endpoints, although better designs have come out since.
• IPv6 provides and uses multicast addresses as part of it's initial design, and its multicast is being used successfully.

Belbone.be is domain from Belgacom Internet backbone the national, previously monopolistic, telephone provider.

The do provide a streaming service used by many institution, such as the Council.

The video content is likely to be encoded on their server and totally outside of the Council IT or AudioVisual team...

The Council is likely bound by the result of a call for tender and can not change provider like that. They will not try a do it yourself solution.

http://whois.6bone.net/cgi-bin/whois?BELBONE-BE

And another point, its not really question of how it'll work in the future.

That's how it works, NOW. Want your own routable /64 IPv6 network?

See here:
http://www.6bone.net/

and here:
http://ipv6tb.he.net/

You can tunnel IPv6 over IPv4, so you can do it right now, with your existing ISP service. Of course, there aren't a whole lot of destinations, yet. But that'll come with time.

Also, you won't remember 128-bit numbers. That's what DNS is for. I feel its a small price to pay for all the improvements in IPv6.

Please, correct me if I am wrong.

Isn't the internet IPv4 only and IPv6 is archieved thru
encapsulations like The 6Bone ?

If so, what's the point of worring about sites not being in the 6bone?

If I am wrong, can you post some links please?

Thanks

Isn't this just 6to4 which has been around for ages?

I hope the DOD isn't building a network larger than this, why the heck would they waste the money on millions of machines that would be needed to be larger than the 6bone was. I can see claims that it is the largest single entity deployment of IPv6 - now that would be a useful claim

You don't need to wait for your ISP to get it. You can get IPv6 connectivity now by using 6over4. See 6bone

I think this is a good thing. Hopefully the use of DNS and Reverse-DNS will become much more prevalent, and we can forget all about using IP's.

Btw, you can get on the IPv6 network now. Join the 6bone. You don't even need a native IPv6 provider, you can use 6over4 to connect to the network over an IPv4 only network.

Yes, no timeline. IPv6, while really cool, fails to solve a single problem at my company. Running it on our LAN doesn't offer us any significant benefit, and the benefits of connecting to 6Bone are slim for a company.

The main "Advanced IP" problem we have is secure communication with remote employees. IPv6 could help with that, but the logisitcal difficulties are too great. Hell, thanks to inconsistant and dodgy implementations by Microsoft, and expensive third-party alternatives, the logistical difficulties of IPSEC, another possible solution, seem too great.

We will get a timeline for IPv6 only after the following happens:
1) Some ISP's start giving their customers IPv6 addresses by default
2) Enough of our clients start requesting direct IPv6 connections to our internet-based services

The first one won't happen until a large majority of home and small business users' desktops have a sane IPv6 stack. Windows XP is the first version of Windows marketed to these clients that can even be argued to have one, and many people are still running Windows 95, so I don't expect to see it for a while.

The current ATT network was created out of the old ibm as well as other networks, i'm not going to read the entire ipv6 routing table (well, it is short enough to read actually, but i'm being lazy) to check for one of the many ATT legacy ASNs or SBC ASNs that they may be using to operate their IPv6 network. I suggest checking 6bone pTLA listing or with the Regional Internet Registry for people that have been assigned IPv6 address space. In the US at least, it's an InterNIC-type company (remember inernic?) called ARIN

... I am waiting for the shipworm [pdf] standard to be formalized. Right now I can only get an ipv6 address for my firewall machine, or if I want to do port forwarding with freebsd I could have one internal machine attached to ipv6, but since I only have one ipv4 address I am out of luck until shipworm becomes a reality.

This, in addition to the fact that I would have to tunnel to get ipv6, the fact that there is nothing I NEED that is available only over ipv6... But I'd still do it just for the experience if it were possible.

...but this story is crud on so many levels.

• 3FFE::/16 is the experimental 6bone space, where you try out allocation policies before settling on a real one. They've settled on a real one. Even better, it's the same in all three (er, four) regions. The 6bone's purpose is fulfilled , we're in production mode and, as was always intended, it's time to think about retiring it.
• How many times: IP address don't cost money. Sure, the RIRs charge for the service of allocation, and your ISP is entitled to charge for the services around them. They do their job pretty well, and with consensus of the community (a rarity in this day and age). Great as Bob Fink is, do you really want to continue trusting address allocation to one guy as a volunteer project?
• You get addresses from your ISP.
• You get addresses from your ISP.
• You get addresses from your ISP. There are loads of them. If you need them, you can have them. The expense is not in getting the damn addresses. "Experimental" does not mean "free". "Production" does not mean "business".
• AftanGustur: IPv6 is not a bastard protocol, routers don't need to fragment anymore, and the IETF is not working on a new damn protocol. You don't cite any sources, so I can't refute it. Please do.

Guys, there are a lot of misconceptions about IPv6. I appreciate this - it's not an intuitive subject, and it's possible to believe you know a lot more about it than you actually do. But, the details are there. Please do the reading and start asking your ISP for connectivity. No, your real ISP. There are people out there who want to deploy this, now, and we're waiting for customer demand. Go nuts!

Dave

No, I don't know what that part about IPv6 being a 128-bit protocol being broken down into 32-bit packets came from??

Anyway, I think the most common ways to implement IPv6 and IPv4 "interoperability" are:

- Use a dual IP layer to support both IPv4 and IPv6. This requires both IPv4 and IPv6 addresses however, and address selection rules. DSTM (Dual Stack Transition Mechanism) might help solve problems with too few IPv4 addresses for the mapping.

- Tunnel the IPv6 traffic over the IPv4 infrastructure. Encapsulate IPv6 packets within IPv4. This method is used on the 6bone.

- Translate the headers with transition tools. Simply translate the IPv4 header into an IPv6 header. This method can only translate information shared by both protocols. This method can be used to make IPv4 hosts on a LAN able to interoperate with an outside IPv6 network, where the translator function much the same as a NAT.

To make auto config possible, you need quite a big host part, at least 48 bits, the size of a ethernet MAC address. Probably they choose 64 bits to allow for larger MAC addresses.

You can read more about IPv6 and its address allocation policies here.

How can you run a box with the IP6 protocol when nothing on your net will talk to it?

There is a common solution to this, called tunneling. Basicly, each IPV6 packet is encapsulated in an IPV4 packet and sent to a remote site where the IPV4 shell is dropped and the IPV6 packet is routed to its destination.

There are public services that do this, most prominently, the 6Bone.

We're already out of addresses - why add more in wireless space? IPv6 has many features that allow for efficient autodiscovery of other nodes, transition mechanisms to move easily from IPv4, multicasting capabilities, etc.

Let's drop this 192.168.x.x and 10.x.x.x stuff and just give everybody their own address. Multiple addresses can easily be used on a single interface as well.

Just something to think about when you want to design something yourself. If you don't want it to make itself extinct in the next few years, think about integrating IPv6 at the outset. It _is_ widespread technology just waiting to happen.

Links:

IPv6.org
hs247.com
freenet6.net
6bone.net

For more reasons on why IPv6 is so cool, and some of the neat things it can do (especially in the field of mesh-wireless, check out some of the technical details here.

We're already out of addresses - why add more in wireless space? IPv6 has many features that allow for efficient autodiscovery of other nodes, transition mechanisms to move easily from IPv4, multicasting capabilities, etc.

Let's drop this 192.168.x.x and 10.x.x.x stuff and just give everybody their own address. Multiple addresses can easily be used on a single interface as well.

Just something to think about when you want to design something yourself. If you don't want it to make itself extinct in the next few years, think about integrating IPv6 at the outset. It _is_ widespread technology just waiting to happen.

Links:

IPv6.org
hs247.com
freenet6.net
6bone.net

For more reasons on why IPv6 is so cool, and some of the neat things it can do (especially in the field of mesh-wireless, check out some of the technical details here.

If you take a look at www.internet2.edu you'll see that they've just (as of August 5) announced native support for IPv6. That certainly is cool, as it's a major step towards getting IPv6 some more mainstream use. Provided that the sites on I2 have the ability to route IPv6, this means that users at the sites will be able to get real IPv6 connectivity to other I2 sites without tunneling. Way cool.

(Of course, anybody can get IPv6 Internet access using tunnels. See freenet6.net and some 6-to-4 information.)

But I2 still isn't the 6bone. ;^)

noah

No, that is simply untrue. There is no connection between the 6bone and Internet2. They are certainly not the same thing. It's perfectly normal to speak IPv4 on Internet2. I do it all the time, as do most people who send packets between major .edu sites. Internet2 is the testbed for not only new software networking technologies, but new hardware technologies as well. There is no hardware involved in the 6bone.

Here is a traceroute that goes over Internet2:

traceroute to infopath.ucsd.edu (132.239.50.184), 30 hops max, 38 byte packets
1 anacreon (18.24.4.1) 0.854 ms 0.510 ms 0.506 ms
2 radole (18.24.10.3) 1.505 ms 1.167 ms 1.547 ms
3 B24-RTR-1-LCS-LINK.MIT.EDU (18.201.1.1) 1.997 ms 1.409 ms 2.448 ms
4 EXTERNAL-RTR-2-BACKBONE.MIT.EDU (18.168.0.27) 1.140 ms 1.274 ms 1.366 ms
5 192.5.89.89 (192.5.89.89) 1.768 ms 1.718 ms 1.191 ms
6 ABILENE-GIGAPOPNE.NOX.ORG (192.5.89.102) 7.337 ms 6.181 ms 6.647 ms
7 clev-nycm.abilene.ucaid.edu (198.32.8.29) 20.210 ms 18.777 ms 19.306 ms
8 ipls-clev.abilene.ucaid.edu (198.32.8.25) 26.019 ms 24.682 ms 26.679 ms
9 kscy-ipls.abilene.ucaid.edu (198.32.8.5) 34.042 ms 35.163 ms 34.527 ms
10 dnvr-kscy.abilene.ucaid.edu (198.32.8.13) 46.358 ms 45.230 ms 44.955 ms
11 snva-dnvr.abilene.ucaid.edu (198.32.8.1) 69.201 ms 70.373 ms 69.657 ms
12 losa-snva.abilene.ucaid.edu (198.32.8.18) 77.485 ms 78.125 ms 77.248 ms
13 USC--abilene.ATM.calren2.net (198.32.248.85) 78.248 ms 77.353 ms 79.467 ms
14 UCSD--USC.POS.calren2.net (198.32.248.34) 81.871 ms 81.249 ms 81.188 ms
15 198.32.248.186 (198.32.248.186) 80.856 ms 81.965 ms 81.400 ms
16 node-b-msfc--ucsd-gw.ucsd.edu (132.239.255.141) 83.473 ms 82.277 ms 80.897 ms
17 muir-rsm--node-b-msfc.ucsd.edu (132.239.255.161) 82.902 ms 82.777 ms 81.225 ms
18 infopath-1.ucsd.edu (132.239.50.182) 83.200 ms * 84.386 ms

Hop 6 is where my packets enter Internet2, and hop 15 is where it leaves it. There is no IPv6 spoken along the way. Now here, just for fun, is an IPv6 traceroute going over the 6bone:

traceroute to 6bone.net (3ffe:b00:c18:1::10) from 2002:121a:12:1804:2a0:ccff:fe57:ccd9, 30 hops max, 16 byte packets
1 3ffe:1ce1:2:1804::2 (3ffe:1ce1:2:1804::2) 1.697 ms 0.391 ms 0.36 ms
2 sipbv6-rtr-sipb-ether.ipv6.mit.edu (3ffe:1ce1:0:b5::1) 509.888 ms 304.953 ms 305.882 ms
3 6bone.merit.edu (3ffe:1c00::3) 306.205 ms 305.879 ms 305.286 ms
4 rap.ipv6.viagenie.qc.ca (3ffe:b00:c18:1:290:27ff:fe17:fc0f) 306.464 ms 306.109 ms 304.732 ms
5 www.6bone.net (3ffe:b00:c18:1::10) 306.389 ms 308.274 ms 307.396 ms

Let me repeat that: Internet2 and 6bone are unrelated!

noah

I think you're confused.

The 6bone was (probably still is!) just a ipv6-in-ipv4 tunnelled network; there was never much of an actual physical infrastructure that ran it. Internet2 is a US-wide really-blazingly-holy-fuck-fast network between educational institutions. It's implemented just as a network that sits beside the Internet; institutions that are connected to it simply use BGP to prefer the prefixes they learn from their I2 link.

that said, the pictures on that site make me feel somewhat shameful about how I've done installs...

and yarr, my gf just got out of the shower and said "you're on slashdot already?" that makes me feel horrible because i'm actually posting. and i never post. dammit.

whee.

The 6bone's Case for IPv6 is an Internet-Draft that expired in 2000!

Programming IPv6 apps is actually quite easy, and actually involves programming protocol family independent code if you want to do it right. On the client end, this basically involves using a function (getaddrinfo(3)) to get a linked list of all addresses associated with a given hostname in any protocol family (IPv4, v6, or even something fun like AppleTalk) and walking along the list until you get a good connection. This has the added advantage that if you are trying to connect to a host that has multiple IP addresses, and some of them are non-responsive (i.e. a round-robin DNS situation), your client will try connecting to each IP address until it succeeds.

If you're trying to learn how to configure and use IPv6 on your hosts, try some of these:

• Microsoft
• The Kame project (*BSD)
• The 6bone for general IPv6 stuff, as well as information on connecting to the experimental IPv6 backbone.
• Peter Bieringer's Linux IPv6 page.

Some people have asked whether we can have both systems and 'switch' between them. Sure you can, but it's not worth it.

As far as I recall (been a long time since I studied this), IPv6 and IPv4 can actually live and work together on the same network.. without being independent.

That is, IPv6 can be used on the backbones and to connect the larger networks, but IPv4 can still be used at a more local level. Gateways can be established that will translate addresses and the benefits of having far more addresses available can be realized.

However, one problem with running both protocols and using a gateway is that the only benefit you get is having more addresses.. but since we're running out of IP addresses with v4, this is kinda important. A local v4 and backbone v6 solution wouldn't help solve local DOS problems, or allow us to use any of v6's advanced features.

But is an Internet wide upgrade to IPv6 really a viable thing to do? It'd be like converting the US to drive on the left side of the road overnight. Even if you did it state by state, you're gunna have major troubles at the state borders.. converting the Net over to IPv6 will be the same.

That said, there is a network called the 6Bone which you can join up to and actually play with IPv6 stuff from your existing IPv4 network. Go, and get your own IPv6 address today!

(Disclaimer: As I said, I studied IP way too long ago, so any updates, corrections or just plain disagreements with my post are welcomed, and indeed encouraged.)

And when will these ISPs start blocking 6bone because of all the trading that's starting to go on there (as well as other less "official" IPv6 nets)? When will RIAA and MPAA discover the real deep dark underground of the Internet?

The following list will keep you occupied about IPv6 for some time... oh just for the record ams-ix is doing NATIVE IPv6 since 1998 now... alongside NSPIXP6 and PAIX and some others to be found at v6nap.net.

First two nice repositories where you can find almost anything IPv6 related:
IPv6 News and Links (hs247)
Open Directory Project Computers/Internet/Protocols/IP/IPng/

And some others important ones which can also be found there:
6bone
Belnet
Bieringer's Linux IPv6 FAQ
Euronet Belgium
IPng
KAME
Kitame's Debian IPv6 Packages
Microsoft IPv6
PuTTY IPv6
SiXXS
Sun Solaris IPv6
Surfnet IPv6
Trumpet IPv6

IPv6 for the future (or something advocating like that :)

My upstream ISP (Demon Internet) is a participant in the 6bone network; so I e-mailed their 6bone contact and requested a small allocation of IPv6 addresses with which I could use on my internal network (all Linux; therefore all capable of IPv4).

I received no response from them whatsoever after three seperate e-mails. I *want* to switch away from IPv4, but my upstream ISP won't let me, while they are making out to the outside world that they are 'spearheading' the IPv6 revolution by announcing that they are a member of the 6bone.

Yes, I have considered applying to other 6bone networks, such as JANET and other UK ISPs, but my upstream ISP would have been ideal for my IPv4IPv6 tunnel (zero routing overheads). Besides, it is a matter of principle.

Anybody running a 6bone site reading this care to comment ? - before you say it, yes, I fulfil the criteria for joining the 6bone (according to http://www.6bone.net/ anyway).

good IPv6 homepage

IPv6 HOWTO

IPv6 Standards

IPv6 Tutorial (PDF)

And the 6bone

Why not run the conversion like the 6bone has? That is, start off with virtual IPv6 between IPv6 supporting sites over IPv4 links, and gradually shift to native IPv6 where possible as more and more of the intermediate "link" sites convert to IPv6? At some point, you switch over core routers one by one so that they're running virtual IPv4 over IPv6 transport, and switch out the last of the IPv4 hardware as it becomes obsolete.

Not that this necessarily provides an incentive for IPv4 users to switch, but IMHO, as a person that's not too knowledgeable about IPv6, I don't see why technically a migration has to be too difficult. Maybe you could make the incentive something like rewarding you with more IPv6 addresses as you move out of IPv4 space - that would definitely move big network operators along, at least.

I'm still not sure how to force a more equal global assignment of the dwindling IPv4 address space. It seems like if the IPv4 afficianados aren't careful, China will just switch to IPv6 immediately, and the rest of the world will get dragged along just so we can continue to communicate with that huge percentage of the human race.

Yes, IPv6 does include encryption. And, it is on by default. All communications are encrypted. Though, IPv6 isn't to widely used yet. But I'm sure if there were an IPv6 napster compatable server (and client for that matter), it would most likely be used alot by people with AUP's that dont allow them to download mp3's, etc. You will also probably want to have a read of either IPv6.org and 6bone.net.

you can find all sorts of info on IPv6, including how to connect to an IPv6 over IPv4 network that exists now at 6bone.net

I use IPv6 with a tunnel to the 6bone. My web and email servers, as well as others, are at this moment IPv6 ready. Here is a very good site for IPv6 information: hs247.com.

Check out: 6bone . And here's a way to get on 6bone from your workstation: Freenet6

sit1 Link encap:IPv6-in-IPv4
inet6 addr: 3ffe:1200:3028:817d:dead:dead:dead:dead/127 Scope:Global
inet6 addr: 3ffe:1200:3028:ff01::2fb/127 Scope:Global
UP POINTOPOINT RUNNING NOARP MTU:1480 Metric:1
RX packets:166 errors:0 dropped:0 overruns:0 frame:0
TX packets:156 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0
RX bytes:22433 (21.9 Kb) TX bytes:18211 (17.7 Kb)

download MSR's IPv6 kit for Win2K

install

connect to 6Bone via Freenet6

install critical applications to test IPv6, like Quake

Enjoy!

Implementation data for other OS's is here.

*scoove*

I had MS Research's IPv6 implementation running for a while on my sacrificial Windows box as part of some v6 experiments earlier this year. While it was still a little bare-bones, it was pretty easy to get running and seemed to play fine with my other v6 machines (BSDs of a couple of flavours using KAME's implementation).
Naturally, there are few immediate practical advantages as it's still in the research stage and deployment is thin on the ground - v6 is only just beginning the transition from research project to production use, but it's there, and it's just about ready to go.
As most v6 internetworking links (currently, primarily as part of the 6bone) are still tunnelled over IPv4, you shouldn't have any problem running v6 over an existing v4 connection if you want to experiment. Home users would probably be best served by checking out Freenet6.
People have all the usual services running in v6 mode over the 6bone, although for me most of the fun is getting packets from point A to point B in the first place..

That crisis point you talk about is coming - just wait until all those new top level domains come on line and folks start realizing we're almost out of IP addresses (and given the trend of new IP allocations, we're lucky if IPv4 lasts another 24 months). IPv6 isn't something ISPs and the backbone will move to voluntarily (with a few farsighted exceptions) - it's going to be one of those gun-to-the-head-of-the-business situations that makes life so enjoyable for us spectators.

Well - additional IPv6 info is available all over the place - try starting at IPv6.com or the IETF IPNG Working Group. The 6Bone is a network of Internet hosts running IPv6 already, and there's a transition planning working group that's arguing, er, discussing, the transition. UNFORTUNATELY, their schedule/roadmap on the transition planning page ends at March of 2000, with an entry to evaluate the state of their roadmap.

A bit more research will reveal some interesting facts - for example, IPv6 switchover will *not* have to be forced. Why? Because it's designed to be COMPLETELY backwards-compatible with existing IPv4 protocol and hardware. As to address space ... ISPs won't be able to charge for what they don't have; namely v4 address space, which will be disappearing shortly. The analogy of IPv6 to mass counterfeiting is completely off the mark. IPv6 is superior in countless ways to IPv4, and ANYBODY that has done any kind of research into it will not dispute that fact, even people that might stand to make a few bucks (temporarily) from the shortage of IPv4 addresses. Do what was suggested by a previous poster - take a couple hours and read up on this issue at: 6bone.net
IPv6.net
IPv6.com
All of those pages have a good number of links to sites that will provide detailed explanations of the issues involved here.

You can also check out:

• MRT
• Zebra
• GateD

These are routers with support for IPv6 routing protocols, such as RIPng, OSPFv6 and BGP4+. (For GateD, you want the GateD 3.6-ipv6 snapshot.)

Last, but by no means least, there's a wealth of information at the "principle" IPv6 sites:

• 6bone.net
• IPv6.com

The main hurdle is the 'average user' base, but as client OS's begin to support IPv6 that hurdle will pass.

It would also seem prudent for the backbone networks to implement IPv6 soon and extend out as far as they can. The more of the net that is already at IPv6 (or at least capeable of routing it) the easier it is for one more host to get on.

Speaking of which, linux users should investigate the 6bone which can supply a tunneled connection to an IPv6 network, created automatically by a web page. Also, it would be nice if a 'killer app' such as napster was improved to support IPv6. Doing so would give users a reason to want IPv6 support on their network.

It seems I remember something about either address allocation having to be free, or the actual transit over the network...I'm not sure which, and I can't find any information on it right now, but I thought either way, it'd be of particular interest with regards to (and possibly opposition of) your idea of micropayments for bandwidth and such.

I'll try to find out some more info on this; anyone know much else about it?

I do, however, know for a fact that you're quite a bit more than wrong about the lack of services over the IPv6 network. They are plentiful, for the users and developers using the current testbed (aka the 6bone). DHIS is one of many free providers of IPv6 testing address allocation, Freenet6 is another. And there are numerous IPv6 capable sites, including FreeBSD's site, portions of Microsoft's site, NASA...

If you check out the main IPv6 sites, such as the 6bone, IPv6.org, IPv6Forum, and a whole lot of others, you'll find the network is quite extensive. Work is being done quite a bit, and it's more than just talk.

It seems I remember something about either address allocation having to be free, or the actual transit over the network...I'm not sure which, and I can't find any information on it right now, but I thought either way, it'd be of particular interest with regards to (and possibly opposition of) your idea of micropayments for bandwidth and such.

I'll try to find out some more info on this; anyone know much else about it?

I do, however, know for a fact that you're quite a bit more than wrong about the lack of services over the IPv6 network. They are plentiful, for the users and developers using the current testbed (aka the 6bone). DHIS is one of many free providers of IPv6 testing address allocation, Freenet6 is another. And there are numerous IPv6 capable sites, including FreeBSD's site, portions of Microsoft's site, NASA...

If you check out the main IPv6 sites, such as the 6bone, IPv6.org, IPv6Forum, and a whole lot of others, you'll find the network is quite extensive. Work is being done quite a bit, and it's more than just talk.

For 6bone info, see http://www.6bone.net/

Check out this site for a semi-informative FAQ: http://faq.v6.wide.ad.jp/ There is also: http://www.ipv6.org/ and http://www.6bone.net/ They claim they are working on a real FAQ and there are apparently some hotows floating around the site...

• www.6bone.net
• www.ipv6.org

Your ISP can be running a cooked hamburger, as far as you're concerned. :) So long as you've an internet connection, the only requirement is that you set up a tunnel, connecting to some existing node on the 6bone. It's as easy as that. :)

Just e-mail the maintainer of the node, get the IPv4 address for their end-point, let them know the address for your end-point, configure SIT0 accordingly, and you're sorted.

(If you get a dynamic IP address, from your ISP, it's slightly more complex. The maintainer'll need to have some kind of script running, to automatically adjust the tunnel, according to what your new IP address is.)

Yes, Linux 2.2 has IPv6, but you have to enable it. You probably have to update some net tools as well. Check out the 6bone web site. 6bone is IPv6 tunnelled over IPv4. There's also a registry there for IP addresses, thought perhaps that'll be one the way out now.

www.6bone.net