dcorbe at hammerfiber.com
Sat Dec 19 16:56:01 UTC 2015
> On Dec 19, 2015, at 11:41 AM, Mike Hammett <nanog at 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
> 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.
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