On 3/05/2009, at 7:53 PM, Matthew Moyle-Croft wrote:
James Hess wrote:
A /62 takes care of that unusual case, no real need for a /56 for
the average residential user; that's just excessive. Before
wondering
about the capabilities of home routers.. one might wonder if there
will even be _home_ "routers" ?
I think you'd want to do a /60 so it's on a "nibble" boundary. But
by then you might as well do a /56.
My personal feeling is that 99% of home networks will use a single /
64, but we'll be giving out /60s and /56s to placate the 1% who are
going to jump up and down and shout at us about it because of some
reason that they feel makes it all unfair or that we're "thinking
like ipv4 not ipv6" etc.
17% of packets leaving an ISP here in NZ were from behind double NAT.
(or, they went through 2 routing hops in the home, which I suspect is
fairly rare)
Why does this happen? $customer has an ADSL router with no wireless,
then they go buy a "wireless router" and plug the ADSL router in to
the "internet" port.
I suspect your market is not that different to NZ.
It's possible that home networks will gain some ability (in a
standard fashion) to use more than one /64, but I doubt it - it's
much easier to do resource discovery on a single broadcast domain
for things like printers, file sharing etc.
The above mentioned sort of stuff will keep happening, I'm sure, and
because the ADSL router and the wireless router are the only devices
on the same subnet, no service discovery things need to happen.
I have an idea brewing to allow routers to forward PD requests. The
idea would be that a BRAS/LNS only assigns a /64 for each PD request,
and the customer router forwards PD requests for routers attached to
their inside interface. That way, we can chain up to 16 subnets in the
home. The BRAS can reserve a /60 or /56 or whatever for each customer
so they are contiguous, or whatever.
--
Nathan Ward