nanog mailing list archives

Re: Arguing against using public IP space


From: Robert Bonomi <bonomi () mail r-bonomi com>
Date: Sun, 13 Nov 2011 18:16:46 -0600 (CST)

From nanog-bounces+bonomi=mail.r-bonomi.com () nanog org  Sun Nov 13 14:15:38 2011
From: William Herrin <bill () herrin us>
Date: Sun, 13 Nov 2011 15:13:37 -0500
Subject: Re: Arguing against using public IP space
To: nanog () nanog org

On Sun, Nov 13, 2011 at 11:38 AM, Robert Bonomi
<bonomi () mail r-bonomi com> wrote:
On Sun, 13 Nov 2011 10:36:43 -0500, Jason Lewis <jlewis () packetnexus com> wrote;
http://www.redtigersecurity.com/security-briefings/2011/9/16/scada-vendors-use-public-routable-ip-addresses-by-default.html

Any article that claims a /12 is a 'class B', and a /16 is a 'Class C', is
DEFINITELY 'flawed'.

Hi Robert,

Give the chart a second look. 192.168.0.0/16 (one of the three RFC1918
spaces) is, in fact, a /16 of IPv4 address space and it is, in fact,
found in the old "class C" range. Ditto 172.16.0.0/12. If there's a
nitpick, the author should have labeled the column something like
"classful area" instead of "classful description."

In the 'classful' world, neither the /12 or the /16 spaces were referencble
as a single object.  Correct 'classful descriptions' would have been:
        "16 contiguous Class 'B's"
       "256 contiguous Class 'C's"


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