nanog mailing list archives
Re: Is it safe to use 240.0.0.0/4
From: William Herrin <bill () herrin us>
Date: Wed, 17 Jun 2015 18:38:32 -0400
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/>
Current thread:
- Is it safe to use 240.0.0.0/4 Luan Nguyen (Jun 17)
- Re: Is it safe to use 240.0.0.0/4 Ca By (Jun 17)
- Re: Is it safe to use 240.0.0.0/4 Luan Nguyen (Jun 17)
- Re: Is it safe to use 240.0.0.0/4 Eduardo Schoedler (Jun 17)
- Re: Is it safe to use 240.0.0.0/4 Luan Nguyen (Jun 17)
- RE: Is it safe to use 240.0.0.0/4 Tony Wicks (Jun 17)
- Re: Is it safe to use 240.0.0.0/4 Rafael Possamai (Jun 17)
- Re: Is it safe to use 240.0.0.0/4 Josh Luthman (Jun 17)
- Re: Is it safe to use 240.0.0.0/4 Ricky Beam (Jun 17)
- Re: Is it safe to use 240.0.0.0/4 William Herrin (Jun 17)
- Re: Is it safe to use 240.0.0.0/4 Ca By (Jun 17)
- Re: Is it safe to use 240.0.0.0/4 Mark Andrews (Jun 17)
- Re: Is it safe to use 240.0.0.0/4 Ricky Beam (Jun 17)
- Re: Is it safe to use 240.0.0.0/4 Ca By (Jun 17)
- Re: Is it safe to use 240.0.0.0/4 Ricky Beam (Jun 17)
- Re: Is it safe to use 240.0.0.0/4 William Herrin (Jun 17)
- Re: Is it safe to use 240.0.0.0/4 Jonas Björk (Jun 17)
- Re: Is it safe to use 240.0.0.0/4 Ca By (Jun 17)
- Re: Is it safe to use 240.0.0.0/4 Ca By (Jun 17)
- Re: Is it safe to use 240.0.0.0/4 John Levine (Jun 17)
- Re: Is it safe to use 240.0.0.0/4 Josh Luthman (Jun 17)