Mark Andrews marka at
Tue Dec 3 00:16:27 UTC 2013

In message <op.w7hmnqvjtfhldh at>, "Ricky Beam" writes:
> On Mon, 02 Dec 2013 17:14:38 -0500, Tony Hain <alh-ietf at> wrote:
> > If you even hint at a  /64 as the standard for residential deployment,
> I never said that should be the standard.  The way most systems do it  
> today, you get a /64 without doing anything.  If that's all you need, then  
> you're done.  If you want more networks, you ask for them via DHCPv6, and  
> you can ask for prefix size you need (you may not get it, 'tho.)   
> Currently, ISPs are defaulting to /60 as that's fair compromise for  
> current networking. It's an easy limit to change, if they're willing to do  
> it.

No, it is not a fair limit.    
> > Trying to develop the automation necessary for consumer plug-n-play
> > subnets shows that even a /56 is virtually unusable...
> I'm the insane one for saying a single /64 and a /60 are perfectly  
> workable today, but every damned device in the home getting it's very own  
> /64 is *NECESSARY*??? If that's your only answer to home automation, then  
> you should quit now, and leave the solar system.
> Multiple networks REQUIRE a working understanding of networking; we have  
> yet to escape that.  I get how people want to make networking as dumb and  
> simple as possible. However, giving an entire /64 LAN to a single device  
> for a single purpose is certifiably insane. If a 2^64 address LAN cannot  
> hold all of the devices in your house, there's something very wrong here.  
> :-) I do understand the desire, and even need, for system isolation, but a  
> LAN-per-device is beyond insane.

So you go from one extreme to another.  One lan to one lan-per-device.
> Also, until 20$ switches become infinitely more intelligent, the typical  
> home network is a flat network. (with a "maybe" on isolation between wired  
> and wireless)  The only logical reason for multiple /64 LANs is multiple,  
> isolated networks... wifi, guest wifi, lan-1, lan-2, lan-3, lan-4 (for 4  
> port router), beyond physical ports are VLANs and thus switches that can  
> handle VLANs, and something has to configure all that.

Each of which needs a /64.  16 subnets is incredibly small.  It is
stifling for developers.  PD can do on demand assignment as long
as the ISP provides enough space for it.  This doesn't have to be
heirachically assigned.  65000 x (2 or 3) routes in a home CPE is
managable without user intervention.  These all get aggregated at
the border router.

You just build in the assignment algorithms ISP's use today to break
up address blocks when you are assigning space customers to allow
for customers (down stream devices) to grow the space they need on
demand into the CPE devices.  This works well enough in reducing
internal routes.

The only thing stifling this is ISP's being measly with how they
hand out address blocks.  If ISPs all hand out /60's this sort of
development just won't happen and it will be entirely the ISP's
fault for being so short sighted.

Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka at

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