On Wed, Jun 17, 2015 at 5:38 PM, Ricky Beam <jfbeam@gmail.com> wrote:
I'll wait for Curran to pop up with various links to reasons why Class E was "abandoned" by ARIN. (short answer: too much broken crap thinks it's multicast!)
Hi Ricky, You may be confused. ARIN never possessed class E; it's held in reserve by IETF. As much as I enjoy a good ARIN bashing, they and John Curran are quite faultless here. IIRC, the short answer why it wasn't repurposed as additional unicast addresses was that too much deployed gear has it hardcoded as "reserved, future functionality unknown, do not use." Following an instruction to repurpose 240/4 as unicast addresses, such gear would not receive new firmware or obsolete out of use quickly enough to be worth the effort. Given how slowly IPv6 is deploying, this choice may prove to have been shortsighted. Had IETF designated class-E as "reserved, future unicast" in 2008 when the issue was debated and asked vendors to update their software to expect 240/4 to be used as unicast addresses, half the problem equipment would already have aged out and we could all be debating whether to make them more RFC-1918 or hand them off to the RIRs. Regards, Bill Herrin -- William Herrin ................ herrin@dirtside.com bill@herrin.us Owner, Dirtside Systems ......... Web: <http://www.dirtside.com/>