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O'Reilly's IPv6 Overview

Scooter[AMMO] writes: "I thought people might be interested in this IPv6 overview currently on O'Reillynet. It touches on what a lot of us already know, like a larger addressable space, security, and mobility, but it also goes into some detail that others may not know yet. It gives information on how addresses are divided between host bits and network bits, address creation, NDP, name resolution, multicasting, localnets, and localsites. It also has RFC references for the more demanding researchers among us."

19 of 40 comments (clear)

  1. Re:here's my beef with this by dodobh · · Score: 2

    Hmmm, since you mention patents, I'll just say:
    DNS. Can you say prior art?

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  2. Re:Why does IPv6 matter right now? by Hellcheese · · Score: 2

    Aparently with Cisco's next major IOS train release, there will be support for IPV6 which I'm certainly looking forward to.

  3. Re:NAT by cheezit · · Score: 2

    Well, okay, sure...but he's talking about the simple case. And if you qualify his point a little, he's right. Portforwarding only enables a single box to act as the server; fine for a home network but not for a corporate LAN. Proxying requires additional code running somewhere to compensate for the problems introduced by the NAT.

    I'm writing an application proxy right now, and guess what---embedding routing info in application packets adds additional routing logic that is separate from your normal routing infrastructure. Can you say security hole?

    He is pointing out how NAT is an incomplete solution to the problem of mapping multiple hosts to a single v4 address. And he's right, it's a pain in the ass.

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  4. Re:Why does IPv6 matter right now? by grub · · Score: 2

    Sorry, I didn't realise Microsoft filed for bankrupcy and *BSD took control of the desktop.

    Tongue in cheek aside, I'd venture to guess a huge percentage of the net's traffic flows through *BSD hardware.

    Microsoft owns the desktop, UNIX owns the net's infrastructure.

    Japan has a huge IPv6 infrastructure ready to roll, this doesn't mean the end users would have to adopt it right away. IPv6-to-IPv4 products exist already.

    grub
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  5. Re:It's a fundamentally brain-dead loser protocol by isdnip · · Score: 2

    Why do you say IPv6 is faster than CLNP?

    The usual excuse is that IPv6 has fixed-length address fields which are easy to handle, say, as struct's. But who says CLNP can't? While CLNP allows many AFIs, it's quite reasonable for the IETF to standardized on a narrow subset, with defined length.

    Little work has been done lately on speeding up CLNP, but I think it should be quite feasible to run it through the fast path.

  6. It's a fundamentally brain-dead loser protocol by isdnip · · Score: 2

    IPv6 is a failure, and has been for the ten years or so that it's been in the works. Now that Cisco has lost most of its technical talent, it's finally pushing something that should have died years ago.

    IPv6 was misbegotten in the first place. There was a working protocol, CLNP, designed for the OSI programme. While OSI had many errors, CLNP, its equivalent of IP, was very good. It had a flexible address field. The first byte was the "authority and format identifier" (AFI), which indicated how to parse the rest. The maximum length was 20 octets but it varied depending on the AFI. Then came the "initial domain identifier" (IDI), which corresponded to network, and the "domain specific part" (DSP), which corresponded to a host on the network (and which could have a subnet-like hierarchy). CLNP was in Cisco, Wellfleet, and other routers over ten years ago! Applied to the Internet, it was called TUBA (TCP and UDP with Bigger Addresses).

    The IETF almost standardized on TUBA; had they done so, the migration would have been done years ago and we probably wouldn't have had NAT, except maybe for some firewalling. The opposition came about because it was tained by OSI, a religious issue among some immature IETF hotheads. Paul {Francis|Tsuchia} of Bellcore and Steve Deering each wrote their own candidate replacements for IPv4, called PIP and SIP (Paul's and Steve's IP, respectively). Both were undergraduate quality. They merged their efforts (the anti-OSI alliance) into what we now call IPv6. At the last minute, Vint Cerf (the Chauncy Gardner of the Internet) switched his vote from TUBA to IPv6. And real progress in the IP layer basically stopped.

    IPv6 doesn't do what it's supposed to. The article at least doesn't claim that its flows are useful for QoS; they're not. The address space is horribly wasteful; because the low-order 64 bits are globally unique (based on MAC), the net result is 64 effective bits, twice. Security is no better than with IPv4. The long addresses result in more header overhead, more bandwidth wasted, and thus either worse performance or more cost. Think of how the bigger headers will work with short-payload streaming payloads!

    They should put this turkey out of its misery. There are LOTS of IPv4 addresses in reserve. Properly allocated, 32 bits should last for a decade or more. Of course many Class As were given out wastefully back in the old days, but we really don't need globally unique addresses for every appliance in every house anyway.

  7. Re:Why does IPv6 matter right now? by grub · · Score: 2

    So you're saying all Cisco and Microsoft (or even Linux) users can take a few minutes to install v6 on their current hardware/OS and have everything working just fine?

    If you run OpenBSD (and I believe FreeBSD), you'll see that you're already IPV6-ready

    (pardon the formatting for this paste)

    $ ifconfig rl0 rl0: flags=8843 mtu 1500 media: Ethernet autoselect (100baseTX) status: active inet 192.168.212.180 netmask 0xffffff00 broadcast 192.168.212.255 inet6 fe80::248:54ff:fe4b:aa9b%rl0 prefixlen 64 scopeid 0x1
    grub
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  8. Imagine the broadcast storms... by ckd · · Score: 2
    Now while the space for network and subnets is sufficient, using 64 bits for addressing hosts seems like a waste. It's unlikely that you will want to have several billion hosts on a single subnet, so what is the idea behind this?

    Can you imagine the broadcast traffic you'd get on a several billion host subnet? I would hope you don't have an IPv6 aware rwhod running. :-)

    1. Re:Imagine the broadcast storms... by sharkey · · Score: 2

      Just run Window 9x, and let NetBIOS take care of it all!

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    2. Re:Imagine the broadcast storms... by interiot · · Score: 2
      • Broadcasts are no longer available in IPv6 in
      • the way they were in IPv4, this is where multicasting comes into play. Addresses in the ff::/8 network are reserved for multicast applications, and there are two special multicast addresses that supersede the broadcast addresses from IPv4. One is the "all routers" multicast address, the others is for "all hosts".

      It seems like the "all hosts" "multicast" thing is similar to what today's netbios and dhcp use. Is this incorrect?
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  9. What of IPv6 on the internet? by Anonymous Coward · · Score: 2
    I hear much about IPv6. But where do I get my ARIN/RIPE/APNIC issued, ok-to-use-on-the-net IPv6 address? How does the routing work? I can't just do this myself without the blessing of my ISP. And what ISPs have IPv6 address blocks allocated to them? What do they charge for them? Why are they charging for them? I thought IPv6 addresses were supposed to be so plentiful that they'd be free? What about the root servers and DNS. Nothing I know of resolves to an IPv6 address. How do I "telnet" to an IPv6 address?

    There seems to be a fscking chasm of missing pieces in the IPv6 rollout. Set it up on your LAN, but I don't see it in the internet arena for at least the next 20 years.

  10. IPv6, NAT, and the little people by ClayJar · · Score: 5

    It seems that every overview of IPv6 I read talks about it eliminating the need for NAT. However, this is only going to be in the case of, for example, a large corporation that is using NAT solely to avoid spending money on IP addresses. In my little piece of the world, I run NAT (IP masq) NOT because there aren't enough addresses but rather because my ISP adds about $7/month for each additional computer, and only up to three on a home account (at least double the price if you want a business account).

    There is no way in H-E-double-hockey-sticks that my ISP is going to just up and say "Okay, now there are plenty of addresses, so we'll stop charging extra for additional computers." They're not going to just let me have six computers connected with IPv6, IPv4, or whatever. For the home user (cable modem, xDSL, modem, or whatever), there will always be a need for NAT.

    1. Re:IPv6, NAT, and the little people by Wesley+Felter · · Score: 2

      There is no way in H-E-double-hockey-sticks that my ISP is going to just up and say "Okay, now there are plenty of addresses, so we'll stop charging extra for additional computers."

      Why? How can you be so sure? What if a small ISP decides to differentiate itself from the competition by saying "Now that IPv6 addresses are practically free, each of our customers gets a /64 at no extra charge."? Although flat-rate pricing might not make sense if you allow that many machines to be connected...

  11. Re:here's my beef with this by mgkimsal2 · · Score: 2

    111.222.333.444.555.666 That would give, to my math, 256^6, or 281 trillion, IP addresses. 281,474,976,710,656 to be exact.

  12. Re:Why does IPv6 matter right now? by wrero · · Score: 4
  13. NAT by SuiteSisterMary · · Score: 3
    It has problems, as the machines hidden behind the global address can't be addressed, and as a result of this, opening connections to them -- which are used in online gaming, peer-to-peer networking, etc. -- is not possible.
    Misleading, if not outright wrong. Portforwarding? Proxying?
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  14. And not even a 31337 comment by MeowMeow+Jones · · Score: 2
    Of course, I'm already running IPv6. I just wish the airlines would get their acts togeather and upgrade the switches in first class.

    Trolls throughout history:

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  15. Why does IPv6 matter right now? by electricmonk · · Score: 3

    We all know that no one will be deploying IPv6 until Cisco starts to support it in its router software. Furthermore, it won't be deployed on a near universal basis until Microsoft decides to get off their asses and support it. So don't count on having any of the benefits of IPv6 at your disposal any time soon...

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  16. Multihoming by dodobh · · Score: 2

    With provider assigned space in the network address, how does any organisation do multi-homing?
    Or do they change addresses each time a link goes down?
    Or will we have a similar situation as of today, where we lease provider space from APNIC/ARIN/RIPE?
    And for smaller organizations which do not have that large requirements?

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