[clug] IPv6

Kim Holburn kim.holburn at gmail.com
Sat Jan 15 23:27:14 MST 2011

On 2011/Jan/15, at 10:57 PM, Paul Wayper wrote:

> Hash: SHA1
> On 01/13/2011 06:43 PM, Steve Walsh wrote:
>> On 01/13/2011 05:57 PM, Paul Wayper wrote:
>>> And just what do you mean by 'backward compatible'?  Do you mean 'my Linux 2.2
>>> machine has to be able to work in an IPv6 world'?  Do you mean 'my IPv6-only
>>> website has to be accessible to IPv4-only machines'?  Do you mean 'I shouldn't
>>> have to learn new addressing schemes, protocols and networking methods, the
>>> old ones should just work by magic'?  Or what?
>> Er....There's new protocols with ipv6?
>> Stateless vs stateful vs Route Advertisement, etc doesn't take that long to
>> understand, once you get into it, but that's the extent of the "new"
>> networking methods
> Yes, that's basically all I was talking about.
> And one should be able to exist in an IPv6 world without having to know what
> the packet headers mean, just as I currently exist in a state of blissful
> ignorance about most of the bits of the IPv4 header.
> However, being able to exist with an IPv6-only machine on the internet and
> fetch pages from an IPv4-only host without any network address translation,
> proxying or other network shenanigans is, AFAICS, completely impossible.  If
> that's what 'backward compatible' means, then I'm afraid Mr Austin is out of luck.

Your ordinary computers connect to the internet through routers.  Packets from your normal computer requires routers to access the internet.  ISPs route those packets, not you or any equipment you control.  If those packets are IPv4 going to the IPv4 internet well and good.  If they are IPv6 going out to the IPv6 internet it's still just a router.  If it's IPv6 going out to an IPv4 site or v.v. it needs a gateway somewhere along the path but it's not a big deal and ISPs will have to provide them sooner or later.  That is not a consumer issue, just like an ISP routing packets to the internet is not in consumer control.

We've seen all this before, you know.  There was a time when there were lots of network protocols and there were gateways between them.  We've had one overriding protocol for so long now we've forgotten.  Back in the day there used to be appletalk, banyan vines, IPX, uucp, bitnet, all with gateways etc.

>> Most network engineers I know are spending their time convincing the boss they
>> need to either upgrade most of their kit, or in come cases, replace it
>> outright, as it's not v6 compatible.
> Or, as Martijn says, has IPv6 stuff in the box but not enabled - you need an
> extra license for that functionality, matey.
>> That in itself is not a small task, and often requires a few months in a test
>> lab and lots of work in EoI, Tenders, Assessments, etc. Couple that with the
>> low number of ISP's that are doing native dual stack v6, and you're fighting
>> an uphill battle, as the boss most of the time can't get it at home, so sees
>> no benefit in spending the dollars to give the engineers "new toys".
> And to the same effect.

Since most of the Western world has snaffled most of the IPv4 addresses, there's not so much pressure for us.  We're hardly even using some of the ranges.  India and China see it very differently.  They don't have the choice.  Eventually we will have the opposite problem.  How do you talk to an IPv6 only host from an IPv4 network?

Kim Holburn
IT Network & Security Consultant
T: +61 2 61402408  M: +61 404072753
mailto:kim at holburn.net  aim://kimholburn
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