Talk:IPv6

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Older messages are archived by chronology: 2003-2005.

Contents

[edit] Discussion of IPv6 Extension Headers seems missing

Either that or I can't find it. In the section titled "IPv6 Packet" there is a brief mention of an "Options Header" to take place of the IPv4 Options field, which would be a good place to discuss or link to a discussion of the various Extension Headers. Seems unlikely, but has it just not been written yet? If not, should I take a stab at it? Michaelshiloh 18:49, 9 January 2007 (UTC)

[edit] Misuse of term VLAN

The reference in the article to VLANs implicitely defines a VLAN as any LAN segment, which is incorrect. The reference should be replaced with a generic LAN. und1sk0 05:59, 8 January 2007 (UTC)

[edit] IPv6 only hosts linked from this page

http://www.ipv6.bieringer.de got removed from the page, it is linked as the IPv6 Calculator page. This page shows one some information about ones IPv6 address. As it is an IPv6-only host (only a AAAA record, no A record) it cannot be reached over IPv4. It indeed thus won't work when you don't have IPv4 connectivity. But it *does* work when you have IPv6 connectivity. One can verify this when having only IPv4 connectivity by going to: http://www.ipv6.bieringer.de.ipv4.sixxs.org this is the URL which passes through the IPv6 Gateway and allows one to view IPv6 only sites with IPv4 only connectivity or IPv4 only sites when having IPv6 only ;) Discriminating IPv6 because you can't reach the site from IPv4 is a bit ehmm weird ;)

Thus: don't remove sites which link to IPv6 only resources unless you have a really deeply argumented reason.


!!!*DON'T* add ipnow.org, it doesn't even have an IPv6 address!!!

$ host -t aaaa www.ipnow.org www.ipnow.org CNAME ipnow.org $ host -t aaaa ipnow.org ipnow.org AAAA record currently not present

Thus it will *NEVER* be able to tell what the IPv6 address of the client is!

People adding it should be marked as vandalism IMHO.

[edit] About 'Confusing' notice

For example, 243f:6a88:85a3:08d3:1319:8a2e:0370:7344. If a 16-bit group is 0000, it may be omitted, and if more than two consecutive colons result from this omission, they may be reduced to two colons, as long as there is only one group of more than two consecutive colons. Thus 0588:2353::1428:57ab is the same as 0588:2353:0000:0000:0000:0000:1428:57ab, but 3906::25de::cade is invalid. If the address is an IPv4 address in disguise, the last 32 bits may be written in decimal; thus ::ffff:192.168.89.9 is the same as ::ffff:c0a8:5909

is confusing.....

For example, 243f:6a88:85a3:08d3:1319:8a2e:0370:7344.

One or more consecutive group of '0000' (16-bit group) may be reduced to two colons. Thus 0588:2353:0000:0000:0000:0000:1428:57ab becomes 0588:2353::1428:57ab. However, reduction can only occur once; hence 3906::25de::cade is invalid. If the address is an IPv4 address in disguise, the last 32 bits may be written in decimal; thus ::ffff:192.168.89.9 is the same as ::ffff:c0a8:5909.

Interestingly, if 0000 in was used to denote IPv4 mapping then we could express it as ::c0a8:5909 or even ::192.168.89.9 in IPv6 format. Ah well, may be the hardware is easier to implement using ffff in this fashion.

by George Dennie to the public domain.

I'm copyediting the article at the moment. What do you think of the new wording in that section? // Pathoschild 14:29, 7 October 2005 (UTC)

[edit] IPv4-mapped vs. IPv6-compatible

IPv4-mapped and IPv6-compatible addresses are different things. An explanation should be added, and also some text about why mapped addresses are a bad idea and are deprecated. -- Marcod'Itri

The article claims that IPv6-compatible addresses are deprecated, not IPv4-mapped. Is this an error? // Pathoschild 14:29, 7 October 2005 (UTC)
No, it is actually true. These are completely different, and only the IPv4-compatible ones are being deprecated at the moment. -- Rdenis 10:08, 13 October 2005 (UTC)

[edit] IPv4 address exhausation

I think it needs to be added, it's not just NAT but the good management by the various NANIC (North American NIC) and the Europen NIC which have helped alleviate the problem as well as the cooperation of address holders in reclaiming all those address given out like candy at the beginning. I believe Xerox or someone had a whole Class A originally?

Why do people keep citing Cisco (a vendor that stands to make money with IPv6 deployment) that IPv4 will run out in 2009? Has Wikipedia become a lap dog for Cisco? This is absolute nonsense. In 2003, there were 100 blocks of /8 IPv4 addresses left and was set to last until 2023! —The preceding unsigned comment was added by 69.105.224.69 (talk • contribs) 07:03, 8 November 2006 (UTC)

Yes, Cisco does stand to make money from IPv6 deployment, but the statistics they give appear to be sound. Looking at the current IPv4 address assignments from IANA, we can see that there are currently 71 /8s shown as "IANA - Reserved", which is the status of blocks which are available (some of the "various registries" space may also be available) however of those 71, 18 cannot be allocated (0/8, 127/8, and 240/4,) leaving 53 /8s plus whatever is unallocated in the "various registries" space left. Also, note this report on IPv4 address allocation, which says that there is currently the equivalent of 54 /8s available (the "IANA pool") and projects that the IANA pool will be fully allocated to RIRs by 2011 and that the RIRs will use up those allocations by 2012. Also, I don't know where the description of a /8 as "256-host" in your version comes from, but it is just plain wrong. -- AJR | Talk 13:56, 8 November 2006 (UTC)

[edit] IPv6 patented by Microsoft

Apparently, there is stories around that M$ has a patent on IPv6. Such an information would appropriately sit well on "Major IPv6 announcements" section. I have however restrained myself from doing so. I am aware there are people who REALLY love patents and that might lead to a stupid edit war. Having it here may be good enough as it will remind us to add it in the front page once we get more information. I found this comment a bit interesting. [1] gathima 15:31, 24 Mar 2005 (UTC)

The story was actually a complete bust as the patent referenced was for Microsoft's method of autogenerating IPs (v4) when no router was present. If it deserves mention here, it is only as a clarification. Good example of how slashdot is not necessarily the most trustworthy news source around. -- gxti 17:24, 4 December 2005 (UTC)

Which is an www.ietf.org/rfc/rfc3927.txt RFC3927 and no there is absolutely no trouble here as the IPv6 method of link-local's existed before Microsoft patented it.

[edit] Syntax /xx unclear

The meaning of the slash followed by numbers was not exactly clear to me when i read the article. I mean the following entries towards the bottom of the article, such as:

::/128,  ::1/128, fe80::/10, etc.

I think it means something like total length in bits together with the implied zeroes, but I have not seen this notation before and it would be nice if the article gave a hint what it meant. Other than that, the article was very helpful, thanks!

Update: This has now been clarified in the article, thank you very much to whoever changed this!

[edit] Autoconf

As I understand it IPv6 should remove the need for DHCP/BOOTP. Either I have misunderstood, or that should be covered here (please!).

Not entirely - IPv6 allows for autoconfiguration of IP addresses and routing but doesn't auto-configure stuff like DNS servers, DNS search domains, NTP servers, etc. So if you want to autoconfigure these things you need to use DHCPv6. However, I believe (someone currect me on this if I'm wrong) that a lot of the stuff like DNS servers have now been allocated anycast addresses so can be configured statically and should Just Work wherever you plug your computer into. User:FireFury

[edit] 'Factual error' fix

Mr. 216.217.194.30:

Regarding fixing my 'factual error': the fact is correct. You just re-worded it in another way. My point was that of the 4billion+ address, one could be assigned to every person on the Earth; and that this is not enough. I will let you keep the change; at least for now.

147.240


The whole article focusess to much on the irrelevant topic of address space and does not mention any of the real capabilities or reasons to adopt IPv6 --- multicast, simplified headers, quality of service, improved security, authentication and privacy, local-use addressing, and so on.

This is deliberate. Address space is the reason why we need IPv6 in the first place. Any other improvements are just things that we might as well include since we are changing the network layer protocol. --Jec 22:33, 6 February 2007 (UTC)

[edit] A question for User:83.99.60.150

Can I ask why you reverted the edits I made last night? [2] My feeling is that the long list of links to the national forums goes against policy that Wikipedia is a not a respository of links, and so I removed those links. I also removed the {{TOCright}} because I find that, unless there is a good reason for having the table of contents on the right, it makes the TOC less useful. (For an example of where it is good, see List of volcanoes, where the TOC is so big it would disrupt the rest of the page if it were in the normal place.) -- AJR | Talk 19:10, 9 October 2005 (UTC)

I agree about the table of contents; it should be on the left. I'm going to change it. There's really no reason for it to be on the right. --Snaxe920 17:17, 22 October 2005 (UTC)

[edit] Data Oriented?

The article starts out, IPv6, or Internet Protocol version 6, is a data-oriented network layer standard .... What does data-oriented mean in this context? Was the intent to contrast it with flow-oriented? --RoySmith 18:15, 8 November 2005 (UTC)

I think this was meant to point out that it's designed for transmission of artibrary data, rather than being just a signalling mechanism like ICMP is.

[edit] Crazy numeral naming

Is it necessary to use definitions of numbers that the average user won't understand? Let's quit the quintillion googleplex stuff and keep it to scientific notation when larger than 1 trillion or so.

  • Fixed! --RoySmith 22:55, 14 December 2005 (UTC)

[edit] Can anyone elaborate on multicast?

I'd like to see a little elaboration on how multicast works under IPv6, if anybody knows... SimonFunk 02:30, 9 January 2006 (UTC)

  • The page about multicast needs a complete rewrite in any case. No, I'm not volunteering.--Jec 18:01, 1 February 2006 (UTC)
  • IPv6 multicast works in exactly the same way that IPv4 multicast works. There are different sizes of padding and address fields in packet headers, but it's roughly the same. -- Anonymous Coward 01:38, 3 October 2006 (UTC)

[edit] Simplified and reworked

I've simplified this page, added a section about the new features, and reworked a number of sections. I believe that the new version is comprehensible by anyone with a working understanding of the IP(v4) suite, so I've removed the confusing tag.

I'd like to go further -- I think that this page tries to do too much, and I think about one third of it could be removed. For example, the section about special addresses could loose about half its weight. I'd also like to remove 90% of the references.

I'll wait for opinions for a week or so, and then go ahead and cut the fat --Jec 20:35, 26 January 2006 (UTC)

I haven't had any feedback on that -- am I or amn't I going to get flamed to death if I remove the (IMHO completely useless) list of national task forces, closed working groups etc. that litters this page? --Jec 18:30, 1 February 2006 (UTC)

Removed a lot of links, basically those that didn't make sense to me. If there's any you think should be added back, go ahead, but please explain why you think they are interesting — if I don't get it, I don't expect the casual reader to get it either.--Jec 20:23, 8 February 2006 (UTC)

[edit] Math and more math

I added in the "crazy" number names in ( ) since the average user might actually look that up and remember it. Instead of trying to figure out what the hell 3.4 x 10 to the 100th power is. Also thought about change the every living person part in it but didn't. Since, well it isn't just for a person...we also use it for printers, servers and so on. Wasn't sure on wording.

  • I have removed the pedantic number names. 10^28 makes sense, octillion doesn't.--Jec 20:23, 8 February 2006 (UTC)

[edit] Inevitable?

Ninjagecko: {which might never happen} -> {which will inevitably happen}

I've reverted this change. This is not about widespread IPv6 adoption, which might or might not be inevitable, this is about IPv4 being completely supplanted by IPv6 and no longer being used, which is definitely not.--Jec 17:58, 1 February 2006 (UTC)

[edit] omitted zeros and acronyms

Say "If a four-digit group is 0000, the zeros may be omitted" BEFORE not after having casually used it leaving readers scratching their heads.

AYIYA: acronyms that an offline reader has no way of figuring out. Don't depend that we can click, or even mouseover, e.g., on our PDA offline.

  • Please clarify. The phrase “generic encapsulation schemes, such as GRE or AYIYA” makes it perfectly clear that AYIYA is a generic encapsulation scheme.--Jec 20:23, 8 February 2006 (UTC)


Following this rule, any group of consecutive 0000 groups may be reduced to two colons, as long as there is only one double colon used in an address. Leading zeros in a group can also be omitted. Thus, the addresses below are all valid and equivalent:

2001:0db8:0000:0000:0000:0000:1428:57ab 2001:0db8:0000:0000:0000::1428:57ab 2001:0db8:0:0:0:0:1428:57ab 2001:0db8:0::0::1428:57ab <-- isn't there 2 doubles in this address? 2001:0db8::1428:57ab 2001:db8::1428:57ab

I'm no expert - I have just read the page and im confused by this -- keep up the good work

  • Fixed, thanks for pointing it out -- RoySmith (talk) 12:52, 8 September 2006 (UTC)

[edit] money spinner?

Well I doubt there is every going to be a demand for so many high speed addresses. Names would be easier to use now. Wonder why POTS scales :-)

[edit] Software (Operating Systems + Applications)

Could someone clarify what this section is for? In a search for OSes that support IPv6, I ended up on the Wikipedia. Maybe there's a seperate page for this? --Allen Huffman

Please clarify.--Jec 16:43, 28 May 2006 (UTC)

[edit] New hardware

I may have missed it but is there a portion of the article (or another article) that describes the impact of switching from IPv4 to IPv6? All of today's hardware (ethernet cards, wireless routers, etc) will need to be replaced, as well as a lot of software. With the high degree of h/w and s/w turnover in the computer biz, I guess this isn't going to be a huge issue, but I still think its worth mentioning.

Wikipedia brown 16:44, 14 May 2006 (UTC)

I've tried to make that clear in the article (`IPv6 is a conservative extension of IPv4'), but obviously I've failed: IPv6 works over the link layers that you know and love, including Ethernet, PPP, 802.11, etc. (but not SLIP). I'll think how to make this clearer.--Jec 16:42, 28 May 2006 (UTC)

- added:
Actually ethernet cards will be fine. They (usually) are working on a lower layer. Remember how IPX/SPX was being used on the same network cards? Same thing here. What won't work on ipv6 if they are not ipv6 compatible:
a) NAT Home routers, such as dsl modems and wireless routers. Actually, they can often be used as a switch, which could work too. But the firewall won't work, and you won't have the privacy of a NAT. Furthermore, you just disabled NAT, so ipv4 connectivity has become very limited
b) Docsis cable modems. Get a Docsis 3.0 compatible one from next year or so.
c) Your PC will typically be fine. Be aware though of onboard firewalls and accelerating network cards.
d) Ethernet cameras
e) Ethernet oscilloscopes
f) Ethernet printers
g) Ethernet Voip phones
h) Ethernet payment systems
i) ...

Some of these might be able to get a firmware upgrade, if it's still properly supported then.

[edit] Number of addresses per <unit>

Any reason why the facts listed in a previous version of the article were removed?

IPv6 is intended to address the concern of IPv4 address exhaustion. There are too few IP addresses available for the future demand of device connectivity (especially cell phones and mobile devices). IPv4 supports 4.2 billion (2564 ≈ 4.294 × 109) addresses, which is inadequate for giving even one address to every living person, much less support the burgeoning market for connective devices. IPv6 addresses this problem by supporting 340 undecillion (655368 ≈ 3.4 × 1038) addresses. For scale, this would allow an average of about 430 quintillion (4.3 × 1020) unique addresses per square inch, or 670 quadrillion (6.7 × 1017) per square millimeter, of the Earth's surface. In other terms, assuming a population of about 6.5 billion humans, there are enough IPv6 addresses such that every atom of every person on Earth could be assigned 7 unique addresses with enough to spare (assuming 7 × 1027 atoms per human).

I would think this information would be useful or interesting to some people.... —Gordon P. Hemsley→✉ 03:43, 6 June 2006 (UTC)

I agree that it helps put a scope on the pure number of available addresses available with IPv6. People know atoms are tiny, and people know there are lots of them in a human, so it helps perspective as well as provide an interesting fact. The surface area example might need to be re-worded to make it clearer, but I'd suggest putting the examples back into the article, assuming nobody has any complaints. --Nick, 65.100.221.52 08:44, 31 July 2006 (UTC)


Perhaps the article could explain more and perhaps justify why 128 and not a smaller number of bits are used. Half the number of bits would provide 4 billion times as many addresses as IPv4, which already seems like a significant overkill. Bandwidth wastage aside, there are other concerns that are possibly slowing acceptance as well, e.g. smaller microcontroller devices may already be pushing their resources to handle IPv4 addresses and would require upgrading to handle IPv6, which may be impractical and expensive. The article does list some reasons such as 128 bits is good for 64 bit architectures (and 64 bit addresses wouldn't be?) and the allocation of large blocks, but I'm not sure if that is a good reason since that's half the reason why we got into a mess with IPv4 in the first place. 85.176.114.183 16:45, 16 June 2006 (UTC)

[edit] First statement

Gentlemen,

when some internet users seek articles herein, they want (and need) to learn the easiest way.

We shall not consider even the hardest article to be read only by those with enough knowledge.

Besides confusing layers with protocols untill I corrected it, the first statement serves both ipv4 and ipv6 concepts but it gives the idea it is only about ipv6:

Internet Protocol version 6 (IPv6) is a network layer IP standard used by electronic devices to exchange data across a packet-switched internetwork.

Perhaps we should think about it.

[edit] Number of addresses misleading

IPv6 supports 3.4×10^38 addresses, or 5×10^28(50 octillion) for each of the roughly 6.5 billion people alive today.

Technically accurate, but misleading. The actual number of addresses available for devices will be considerably less than this. In a typical situation my ISP might assign me a 64 bit block of addresses, of which precisely two will be used by me. (Even if in the future we have fridges and washing machines connected to the internet, there still no possible way I could use up all 2^64 addresses). Then there are loads of addresses wasted in other ways (eg. the 6to4 prefix, ::ffff:, inefficient assignment to ISPs, etc.) I think the article should reflect this. Richard W.M. Jones 09:20, 16 July 2006 (UTC)

I think you're misunderstanding. It's not talking about the actual distribution of addresses, but just pure numbers. Total number of possible addresses divided by number of humans equals X addresses per human. --Nick, 65.100.221.52 08:38, 31 July 2006 (UTC)

[edit] Bigger address space not (only) purpose of IPv6

I have slightly changed the wording of the second introductory paragraph to remove the idea that bigger address space is the *main* purpose of IPv6. However, as the whole paragraph remains, the idea that "bigger address space is an important aspect of IPv6" is intact. I think that's enough.

IPv6 brings a load of improvements, and bigger address space is the most user-visible one of them. As such, it is indeed important to point it out, as it is done. That said, I'm not familiar with the design history of IPv6. It may be that increasing the address space was the first aspect that led to the creation of the protocol.

I know this comes out as pedantic, but hey, isn't that what an Encyclopedia is all about? ;)

That said, the IPv6 Features section still lists bigger address space as the "main" improvement. I might change that too, if the current change doesn't provoke a flamefest.

Please don't -- the address shortage is the very reason why we're getting IPv6. Everything else is secondary.--Jec 22:41, 23 August 2006 (UTC)

Speaking as a technically inclined person who's neither familiar with the technology nor the policies around this, I have a question: If the limit of the 32-bit address space is the main (or even a large) driver behind v6, why is IANA handing out /32s to everybody and their little brother? Doesn't that lock the whole system right into 32-bits again? The article indicates that the natural way to think of v6 addresses is as a 64-bit network with a 64-bit number of machines on each. If there is a technological reason for 32-bit prefixes, this ought to be mentioned on the page, I'd think. (If it is strictly a policy thing, then it might not be germane).Iron Condor 17:28, 23 February 2007 (UTC)
Meh. I'm less excited about mitigating the supposed address shortage. With IPv4/NAT, we are effectively extending the global 32-bit host address space into a global 48-bit TCP and UDP address space in exchange for signaling asymmetry and loss of end-to-end transparency (see RFC 3424 for an explanation of what I mean by that). There are a lot of addresses in a 48-bit space, and it's not clear to me that scarcity of those will ever lead to significant routing/address-assignment inefficiencies. The real purpose of IPv6, it seems to me, is that it makes signaling asymmetry and end-to-end transparency optional again, instead of mandatory, as is the case today with IPv4/NAT. Of course, this is a controversial view, but this is the discussion page. Jhwoodyatt 01:14, 6 April 2007 (UTC)

[edit] ICANN Announcement

How about adding something to the page from ICANN's announcement at http://www.icann.org/announcements/announcement-14jul06.htm?

[edit] Larger address space

I have issues with this sentence:

"A technical reason for selecting 128-bit for the address length is that since most future network products will be based on 64 bit processors, it is more efficient to manipulate 128-bit addresses."

First, I don't think we can categorically state what kind of architecture future network products will use. Second, the latter part of the sentence makes no sense; The manipulation is "more efficient" than what? It sure isn't more efficient than the manipulation of 64-bit addresses.

I'd like to see a reference for the claim or see it taken out completely. --Teemuk 13:27, 4 September 2006 (UTC)

I have rewritten this section and removed this sentence. Making things easy for 64-bit computers was never a design consideration as they were very rare in the early 1990s. Wrs1864 00:36, 3 January 2007 (UTC)

[edit] Criticism?

I was a little surprised not to see more drawbacks of IPv6 given in the article. Several advantages are given, and the article twice calls IPv6 a "conservative extension of IPv4", which seems at least debatable. If the only thing discouraging the use of IPv6 is the availability of NAT, as the article seems to imply, why is adoption so low? Wmahan. 07:11, 11 September 2006 (UTC)

[edit] addresses per gram of the Earth

In the introduction of this article, we had said that "IPv6 supports 3.4×1038 addresses, or 5×1028(50 octillion) for each of the roughly 6.5 billion people alive today, or about 800 addresses for each gram of matter in the Earth." which User:Roadrunner7 changed to say "almost 57 billion addresses" per gram[3], and User:Richard W.M. Jones reverted Roadrunner7's edit[4], on the ground that the chage was uncited. We don't currently have a citation for either number, but it's fairly easy to calculate the number, which comes out as Roadrunner's 57 billion: There are (less reserved parts of the number space) 2128 IPv6 addresses, and per Earth the mass of the earth is 5.9742 * 1024kg. So, the number of addresses per gram of the Earth is \frac{2^{128}}{5.9742*10^{27}} = 5.696*10^{10} addresses per gram, which it is quite reasonable to call "almost 57 billion". So, do we find a citation for this number, or do we want to just remove it altogether (or possibly provide a cite for the Earth's mass and show the calculation)? -- AJR | Talk 16:43, 19 September 2006 (UTC) 5*10^28/(5.9742 * 10^27)

My math agrees with Roadrunner7's and yours. If instead you take the 5×1028 figure (upper bound on the number of addresses per person on Earth) and divide that by the mass of the Earth in grams, you get about 8, which is not still 800.
Personally I think such statements are unencyclopedic and add no value to the article. The number is huge by any practical standard, and no end of silly calculations could be invented to show it. If necessary we could link to an Orders of magnitude (numbers) to give some perspective. Wmahan. 17:49, 19 September 2006 (UTC)
I agree that these calculations add no value to the article. It should be enough to state the theoretical maximum number of addresses is 3.4×1038, and perhaps mention that in reality the address allocation schemes will limit the number of useful addresses. If somebody wants to calculate how many addresses per [insert an irrelevant unit here] IPv6 theoretically provides, they may do it themselves. Including these calculations here only makes the article seem amateurish.--Teemuk 07:59, 28 September 2006 (UTC)
OK, glad someone actually did the maths. I was worried because Roadrunner7's account had made just this single change which seemed wrong, but is seemingly correct. Richard W.M. Jones 20:49, 19 September 2006 (UTC)
I'm glad someone backed me up on this. I did make the Earth word linked also in my change, so that anyone could look up the facts about the mass of the earth and see for themselves that my caluculations are correct (isn't that cited enough?). Mr. Jones: Why did it seem wrong, what I did? When someone makes a change to some incorrect numbers in an article, the least you can do before changing it back, is to check the numbers yourself. If you don't know, then don't "fix". I thought the whole point of Wikipedia is that anyone can correct mistakes they find, or add facts. Just because it was my first contribution, it doesn't mean I'm wrong. Roadrunner7 09:35, 20 September 2006 (CET)
Unfortunately I've been spending a large amount of time recently reverting vandals who create one-shot accounts and then vandalise articles. In any case, welcome to Wikipedia, and please use the edit summary to summarise changes. Richard W.M. Jones 08:00, 20 September 2006 (UTC)

[edit] "IPv6 Packet" chart problem

Someone who can edit .PNG files please fix a small problem with the chart laying out the packet header bits? The bit numbers down the side read 0, 64, 128, 192, 256, ...but there is no 320 at the bottom. IPv6 headers are in fact 320 bits (40 bytes). --Shyland 17:08, 30 September 2006 (UTC)

[edit] 1 address per atom

Just for fun, I decided to examine the assertion, "statements that IPv6 provides enough address space to give an address for each atom in the universe or even for each atom on Earth are highly exaggerated". Our Earth article lists the Earth's mass as about 6e24 Kg, or 6e27 g. If we assume (for the moment), that most of the Earth is Hydrogen (that's certainly true for the universe, but probably not for Earth), then there's 6e27 x 6e23 (Avogadro's number) = 36e50 or about 4e51 atoms in the Earth. If we make a more reasonable assumption that the average atomic weight of an atom in the Earth is 40, then we still come up with 1e50 atoms. Sorry, we've run out of IPv6 addresses for atom-net :-) -- RoySmith (talk) 19:51, 31 October 2006 (UTC)

Are you supposed to convert the mass to grams and then multiply that by Mr. Avogadro? I don't do chemistry (I do physics and maths), but the SI unit of mass is kg, so it would seem to me that you should do 6e24 × 6e23, instead of 6e27 × 6e23, if you want the units to be homogeneous. But, like I said, I don't do chemistry. ;) Stuart Morrow 21:38, 30 January 2007 (UTC)
Nevermind, I just looked it up, you were right, and I was wrong. Stuart Morrow 21:39, 30 January 2007 (UTC)

[edit] "I'm not quite sure I believe that..."

Every time I hear stuff about IPv6 I hear something I don't quite get, or don't believe. If I can just run some of these ideas past you guys, verifying (or not!) their accuracy.

  • 1. IPv6 will eliminate dynamic IP systems. Well, I sure hope so myself, since that makes spammers' jobs one great chunk harder. And it's certainly true that ISPs will not need to offer dynamic IPs anymore. But will there be anything stopping them from continuing to do so?
    • No, there's nothing stopping them from assigning IPv6 addresses dynamically. In fact, there is a DHCP version being designed to do just that. Dynamic autocofiguration is likely to remain very popular even with IPv6 since the ISPs typically want to have maximum control over their network. The stateless autoconfiguration depends on the MAC address of the NIC, which can be faked easily.--Teemuk 08:19, 6 November 2006 (UTC)
  • 2. IPv6 will eliminate ISPs themselves. I heard this somewhere, can't remember where. I lack the theoretical understanding of telecommunication to tell whether or not this is likely.
    • No, I have no idea what would prompt such an assertion. ISPs will be just as necessary as they're today.--Teemuk 08:19, 6 November 2006 (UTC)

Your insight is appreciated. BrokenBeta [talk · contribs] 20:05, 4 November 2006 (UTC)

[edit] More than one :: ambiguous?

"Having more than one double-colon abbreviation in an address is invalid, as it would make the notation ambiguous" does not seem to me to be a sound statement. It would be possible to adopt the convention "if there is more than one double-colon in an address, then each of them represents exactly one 0000 group". I understand if that is not in fact the accepted convention, but I think the notation would not necessarily be ambiguous. But I'm not an expert here, just pointing out. David Brooks 02:16, 14 December 2006 (UTC)

No, that is not the case, if you have: "2001:db8::5555::1234" is that
"2001:db8:0000:0000:5555:0000:0000:1234" or
"2001:db8:0000:0000:0000:5555:0000:1234" or
"2001:db8:0000:5555:0000:5555:0000:1234"?
As such one can't compress an IPv6 address to have two double-colon's in it, which
would make it ambiquous.
User:JeroenMassar 20:10, 14 December 2006 (UTC)
I was saying it isn't necessarily ambiguous, which is what's implied in the text. Instead, it is ambiguous by definition. You could resolve the ambiguity as I suggested, but the standard just declares it ill-formed instead, and that's clearly fine. The resolution I gave as a possible alternative would declare your example ill-formed (too short). And I think you mistyped the expansion in your 3rd example (5555 -> 0000). David Brooks 22:32, 14 December 2006 (UTC)

[edit] "Unique Addressess" missing a digit group?

I personally like the example used for demonstrating the number of unique addresses. However, the number appears to be incorrect. In a glance the number appears to be correct, but close inspection shows that it is missing a digit group, maybe? The number listed is 340,282,366,920,938,463,374,607,431,768,211,456 which is 3.40282366920938463374607431768211456e+35, correct? However, 2^128 is actually 3.4028236692093846346337460743177e+38 on my caculator. I'm not sure which digit group is missing, but my guess is the last one. Can anyone help with this? 63.101.242.220 22:22, 2 January 2007 (UTC)

Obviously, your calculator is rounding. That's pretty common - very few calculators actually have 128 bit accuracy.Iron Condor 00:48, 24 February 2007 (UTC)
My text editor says that the exact value does indeed have a repeated 463 group, so the recent change was incorrect. Wrs1864 22:26, 2 January 2007 (UTC)

[edit] RFC1918

The article should mention private IPv4 addresses as a stop-gap for IPv4 address conservation.. und1sk0 11:02, 6 January 2007 (UTC)

The article does mention NAT, which is primarily used with private addresses. NAT, by itself, really doesn't primarily reduce the IPv4 exhaustion so I guess reworking the article to more directly mention primvate address and mention NAT in conjunction to it would be good. Wrs1864 22:50, 7 January 2007 (UTC)

[edit] Too technical

This article makes very little sense to someone who's not familiar with network administration. Perhaps that's unavoidable with this subject matter, but I came here from the Windows Vista article to see what the heck IPv6 is and I still don't really have any greater idea of what it is than I did before. :) 205.157.110.11 22:16, 10 January 2007 (UTC)

[edit] Error in Notation section?

Says here: "Thus, ::ffff:1.2.3.4 is the same address as ::ffff:102:304". I'm not IPv6 expert, but if last one is supposed to be hex then sure those addresses aren't same. 80.235.27.168 01:48, 1 February 2007 (UTC)

  • What exactly is the problem? The first one is in decimal notation (well, the last 4 bytes), the second is in hex.--Teemuk 12:29, 6 February 2007 (UTC)
  • Still, shouldn't the bytes be reversed when written as word? That is ::ffff:201:403 80.235.27.168 16:13, 8 February 2007 (UTC)
    • No. You're probably thinking about the way certain processor architectures store words in memory.--Teemuk 09:28, 13 February 2007 (UTC)

Question from a non-native speaker: There's a change in section "Notation" from "hexadecimal digits" to "hexadecimal numbers". IMHO

fd09cafe

is a hex number, consisting of eight digits. Hence I'd like to see the change reverted to the original text (eight groups of four hex digits). Comments?

  • I agree it should be "digits" or maybe "numerical digits"; I'll revert it. As a side note, I guess strictly speaking fd09cafe would be a hexadecimal "numeral" representing a certain "number" (another numeral representing the same number would be 4245277438).--Teemuk 09:11, 19 February 2007 (UTC)

[edit] Error in Network Notation?

"For example, 2001:0db8:1234::/48 stands for the network with addresses 2001:0db8:1234:0000:0000:0000:0000:0000 through 2001:0db8:1234:0000:0000:FFFF:FFFF:FFFF"

Wouldn't it be from address 2001:0db8:1234:0000:0000:0000:0000:0000 to 2001:0db8:1234:FFFF:FFFF:FFFF:FFFF:FFFF ?

136.182.158.129 17:44, 2 March 2007 (UTC)

[edit] Leet Speak

Did anyone notice that the IP mentioned in the Addressing section ends with "1337" (leet)?  :) —The preceding unsigned comment was added by 204.13.204.2 (talk) 15:20, 7 March 2007 (UTC).

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