[185633] in North American Network Operators' Group
Re: CIDR Utilization
daemon@ATHENA.MIT.EDU (Owen DeLong)
Mon Nov 2 13:47:54 2015
X-Original-To: nanog@nanog.org
From: Owen DeLong <owen@delong.com>
In-Reply-To: <CA+OqHhABBFK6YQ9nQCRfOvP58maV5Kx4wj3oYPpFWrDyJDcapg@mail.gmail.com>
Date: Mon, 2 Nov 2015 13:47:41 -0500
To: John Steve Nash <john.steve.nash@gmail.com>
Cc: nanog@nanog.org
Errors-To: nanog-bounces@nanog.org
The results appear to be missing 192.168.0.0/32.
Is this intended behavior?
192.168.0.8/27 is not a valid CIDR =E2=80=94 It actually represents an =
address within 192.168.0.0/27, so actually, rather than missing =
192.168.0.0/32, one could argue that there are erroneous reports for =
192.168.0.2/31, 192.168.0.4/30 being available.
192.168.0.64/26 encompasses 192.168.0.68/32 and 192.168.0.96/29, so =
there=E2=80=99s also an allocation conflict potential there.
I thought I understood what you were looking for from your question, but =
your example creates significant confusion.
Owen
> On Oct 30, 2015, at 8:51 PM, John Steve Nash =
<john.steve.nash@gmail.com> wrote:
>=20
> Hi,
>=20
> I'm looking for any tool or a way I could specify a CIDR and the =
prefixes
> that are being used within this CIDR and the tool show me all free
> supernets.
>=20
> Example:
>=20
> 192.168.0.0/24 - CIDR
>=20
> Used subnet's:
>=20
> 192.168.0.1/32
> 192.168.0.8/27
> 192.168.0.64/26
> 192.168.0.68/32
> 192.168.0.96/29
>=20
> Tool Result =3D> Free Subnet's:
>=20
> 192.168.0.2/31
> 192.168.0.4/30
> 192.168.0.32/27
> 192.168.0.128/25
>=20
> Regards,
>=20
> John
