> On Dec 20, 2015, at 11:57 AM, Mike Hammett <na...@ics-il.net> wrote: > > However, keeping back 64 bits for the host was a stupid move from the > beginning. We're reserving 64 bits for what's currently a 48 bit number. You > can use every single MAC address whereas IPS are lost to subnetting and other > such things. I could have seen maybe holding back 56 bits for the host if for > some reason we need to replace the current system of MAC addresses at some > point before IPv6 is replaced.
EUI-64 isn’t the only thing out there that expects hosts to have 64-bit addresses. That was only an example. > > There may be address space to support it, but is there nimble boundary space > for it? Yes. Do the math. If every end user got a /48 there’s still 281 *trillion* subnets to go around. The limiting factor in IPv4 is that nobody expected to be able to connect 4 billion devices to the Internet when it was conceived. I really doubt that we’ll see 281 trillion people walking around any time in the next 1000 generations of human civilization. IPv6 is here to stay. > > The idea that there's a possible need for more than 4 bits worth of subnets > in a home is simply ludicrous and we have people advocating 16 bits worth of > subnets. How does that compare to the entire IPv4 Internet? You’re still stuck on “LOOOOL ADDRESSES.” > > > There is little that can be done about much of this now, but at least we can > label some of these past decisions as ridiculous and hopefully a lesson for > next time. There isn’t going to be a next time. > > > > > ----- > Mike Hammett > Intelligent Computing Solutions > http://www.ics-il.com > > ----- Original Message ----- > > From: "Daniel Corbe" <co...@corbe.net> > To: "Mike Hammett" <na...@ics-il.net> > Cc: "Mark Andrews" <ma...@isc.org>, "North American Network Operators' Group" > <nanog@nanog.org> > Sent: Saturday, December 19, 2015 10:55:03 AM > Subject: Re: Nat > > Hi. > >> On Dec 19, 2015, at 11:41 AM, Mike Hammett <na...@ics-il.net> wrote: >> >> "A single /64 has never been enough and it is time to grind that >> myth into the ground. ISP's that say a single /64 is enough are >> clueless." >> >> >> >> LLLLOOOOOOLLLLL >> >> >> A 100 gallon fuel tank is fine for most forms of transportation most people >> think of. For some reason we built IPv6 like a fighter jet requiring >> everyone have 10,000 gallon fuel tanks... for what purpose remains to be >> seen, if ever. >> >> > > You’re being deliberately flippant. > > There are technical reasons why a single /64 is not enough for an end user. A > lot of it has to do with the way auto configuration works. The lower 64 bits > of the IP address are essentially host entropy. EUI-64 (for example) is a 64 > bit number derived from the mac address of the NIC. > > The requirement for the host portion of the address to be 64 bits long isn’t > likely to change. Which means a /64 is the smallest possible prefix that can > be assigned to an end user and it limits said end user to a single subnet. > > Handing out a /56 or a /48 allows the customer premise equipment to have > multiple networks behind it. It’s a good practice and there’s certainly > enough address space available to support it. > > >
