DHCPv6, was: Re: IPv6 Finally gets off the ground

Thu Apr 12 09:11:54 UTC 2007

On 10-apr-2007, at 18:12, David W. Hankins wrote:

>> IPv6 has had operating system and router support for years.

> I'd have to object with such a blanket statement.

I have a Cisco 2500 with software from 1999 and a Windows XP box with  
software from 2001, both supporting IPv6, sitting here... I didn't  
get my first Mac until 2002, but that one supported IPv6 at that  
point, too.

> I don't think you can say you support IPv6 (from an ISP's point of
> view) without DHCPv6, since I don't think anyone at a large ISP
> sized scale is going to leave address assignment up to RTADV.

There is a provisioning problem with IPv6, yes. For instance, you  
can't get an IPv6 address over PPP, like you can with IPv4. But I  
don't see how DHCPv6 solves that. I can see how _enterprises_ might  
like DHCPv6, because hosts coming up with the bottom 64 bits of the  
address is just way to anarchistic for them. But ISPs don't care.  
They'll just give out prefixes rather than individual addresses, so  
the router advertisements vs router advertisements + DHCPv6 question  
never comes up. (Yes, if you have DHCPv6 you still need RAs because  
DHCPv6 can't give you a default gateway.) And customers rarely  
connect their hosts directly to ISP-controlled boxes these days,  
there is usually some kind of home gateway involved.