Addressing plan exercise for our IPv6 course

Fri Jul 30 08:53:45 UTC 2010

On Jul 30, 2010, at 12:27 AM, Matthew Walster wrote:

> On 29 July 2010 18:08, Leo Vegoda <leo.vegoda at icann.org> wrote:
>> There's a good chance that in the long run multi-subnet home networks will become the norm.
> 
> With all due respect, I can't see it. Why would a home user need
> multiple subnets? Are they really likely to have CPE capable of
> routing between subnets at 21st Century LAN speeds? Isn't that
> needlessly complicating the home environment?
> 
1.	Because eventually, home environments will become cognizant
	of the fact that they need more than one security profile for more
	than one usage.

	Because the number of devices present in home networks today
	is a very tiny fraction of the likely number in just a few years as
	new applications are developed to take advantage of the restoration
	of the end-to-end model of the internet.

	Because the devices in homes today represent a small fraction
	of the diversity that is likely within the next 10 years.

2.	Yes, they are already available. A moderate PC with 4 Gig-E
	ports can actually route all four of them at near wire speed.
	For 10/100Mbps, you can get full featured CPE like the SRX-100
	for around $500. That's the upper end of the residential CPE
	price range, but, it's a small fraction of the cost of that functionality
	just 2 years ago.

3.	Not at all. In fact, one could argue that limited address space,
	NAT, uPNP, and a number of the things home users live with
	today complicate the home environment much more than a
	relatively simple router with DHCP-PD and some basic
	default security policies for such subnets as:

		Home sensor network and/or appliances
		Kids net (nanny software?)
		Home entertainment systems
		Guest wireless
		General purpose network

> Additionally, when it comes to address size, Andy Davidson et al make
> a good point - you request what you expect to assign, and due to the
> massive availability of the IPv6 address space, you generally get it
> assigned within a few days. It just seems *wasteful* to me. /32 is a
> lot of space, if most customers are only going to have a few machines
> on one subnet, why not just give them a /64 and have an easy way to
> just click on a button on your customer portal or similar to assign a
> /48 and get it routed to them.
> 
Why go to all that extra effort instead of just giving them the /48 to begin
with? What is the gain to the preservation of integers?

How's this sound... Try IPv6 as designed with liberal address assignments
in favor of good aggregation for 2000::/3. If we run out of that, I'll support
any reasonable proposal to be conservative with the other 7/8ths of the
address space if I'm still alive when we get there.

Owen