On Dec 2, 2013, at 5:14 PM, Tony Hain <alh-i...@tndh.net> wrote: > Ricky Beam wrote: >> On Fri, 29 Nov 2013 08:39:59 -0500, Rob Seastrom <r...@seastrom.com> >> wrote: >>> So there really is no excuse on AT&T's part for the /60s on uverse > 6rd... >> >> Except for a) greed ("we can *sell* larger slices") and b) demonstrable > user >> want/need. >> >> How many residential, "home networks", have you seen with more than one >> subnet? The typical household (esp Uverse) doesn't even customize the >> provided router. Even a CCIE friend of mine has made ZERO changes to his >> RG -- AT&T turned off WiFi and added the static block at install. (I know >> NANOG is bad sample as we're all professionals and setup all kinds of > weird >> configurations at "home". I have 3 nets in continuous use... a legacy > public >> subnet from eons ago (I never renumbered), an RFC1918 subnet overlapping >> that network (because it's too small), and a second RFC1918 net from a >> second ISP) >> >> I wouldn't use the word "generous", but a /60 (16 "LAN"s) is way more than >> what 99% of residential deployments will need for many years. We've >> gotten by with a single, randomly changing, dynamic IP for decades. Until >> routers come out-of-the-box setup for a dozen networks, non-networking >> pros aren't going to need it, or even know that it's possible. (and the > default >> firewalling policy in Windows is going to confuse a lot of people when >> machines start landing in different subnets can "see" each other.) >> >> Handing out /56's like Pez is just wasting address space -- someone *is* >> paying for that space. Yes, it's waste; giving everyone 256 networks when >> they're only ever likely to use one or two (or maybe four), is > intentionally >> wasting space you could've assigned to someone else. (or >> **sold** to someone else :-)) IPv6 may be huge to the power of huge, but >> it's still finite. People like you are repeating the same mistakes from > the early >> days of IPv4... the difference is, we won't be around when >> people are cursing us for the way we mismanaged early allocations. >> Indeed, a /64 is too little (aka "bare minimum") and far too restrictive, > but it >> works for most simple (default) setups today. Which leads to DHCPv6 PD... > a >> /60 is adequate -- it's the minimal space for the rare cases where > multiple >> nets are desirable or necessary. The option for /56 or even /48 should > exist >> (esp. for "business"), but the need for such large address spaces are an >> EXCEPTION in residential settings. (and those are probably non-residential >> users anyway.) [FWIW, HE.net does what they do as marketing. And it works, >> btw.] > > The rant above represents a braindead short-sighted thought process. If you > focus on the past as justification for current actions, you guarantee that > the future will always look exactly like the past. If you even hint at a /64 > as the standard for residential deployment, you will find that all the CPE > vendors will hard code that, and you will never get it undone when you > change your mind. All because you stated up front that they will only ever > need what they have been using in the past. > > You don't see multi-subnet residential today from the consumer viewpoint, > but they do widely exist supporting deployment of "watch your dvr from any > set-top", where a premise subnet handles that traffic off of the consumer > lan. That one example is why there should NEVER be a /64, because you are > already at 2 subnets that should be using the same shorter prefix. Trying to > develop the automation necessary for consumer plug-n-play subnets shows that > even a /56 is virtually unusable. A /55 makes more sense for a topology with > moderate constraints, but if you are already shorter than a 56, it doesn't > make sense to stop there. This is a hard concept for "professional network > engineers", because their market place value is based on the ability to > efficiently manage topologies to fit within address resource constraints. > Consumers have no desire to understand the technology, they just want to > plug stuff together and have it sort out what it needs to do. That > unconstrained topology coupled with unmanaged device automation requires > excess address resource. > > YES THAT IS A WASTE. But having the address space sitting on the shelf at > IANA when someone comes along with a better idea in the next few hundred > years is also a waste. Get over it, the address space excessively larger > than we will ever deploy so it is wasted ... The only open issue is how we > utilize the resource until the next thing comes along. If it sits on the > shelf, you constrain innovation. If you 'waste it' by deploying it before > people can really use it, you piss-off the existing engineering staff. From > my perspective, the latter will die off, but stifling innovation robs future > generations of capabilities they could/should have had to make the world a > better place. > > Tony >
My kudos to Tony for an excellent summary. The only thing he missed is the tremendous waste of people resources involved in micro-managing address assignments. Those who cannot learn from history are condemned to repeat it. The available IPv6 address space, even constrained to /64 as a maximum prefix, is far beyond concern for decades. In addition, really intelligent network service providers calculate the budget for personnel to micro-manage address space. For example, a provider that by default uses a /64 for the CPE WAN link and a separate DHCP-PD assignment for customer networks will almost never have to revisit the issue, but has the flexibility to do so as needed. And, the lazy user, as cited above, will receive a working network without special effort. So just do the cost-benefit analysis including business office, deployment, and operations personnel and systems versus a purported “waste” of some integers which potentially will not affect us until 2090 if at all. James R. Cutler james.cut...@consultant.com
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