DoD IP Space

Mark Andrews marka at
Fri Feb 12 03:02:53 UTC 2021

> On 12 Feb 2021, at 12:41, Izaac <izaac at> wrote:
> On Thu, Feb 11, 2021 at 06:29:42AM -0800, Owen DeLong wrote:
>> Ridiculous… TCP/IP was designed to be a peer to peer system where each endpoint was uniquely
>> addressable whether reachable by policy or not.
> I think that is a dramatic over-simplification of the IP design criteria
> -- as it was already met by NCP or even a single ethernet segment.  But
> that's an aside.  I recommend that you read rfc1918, with a particular
> focus on Section 2, because I'm about to employ its language:
> When dealing at large scale, an incompetent network engineer sees a
> network under their control as a single enterprise.  Whereas a competent
> network engineer recognizes that they are actually operating a
> federation of enterprises.  They identify the seams, design an
> architecture which exploits them, and allocate their scarce resources
> appropriately.
>> IPv6 restores that ability and RFC-1918 is a bandaid for an obsolete protocol.
> So, in your mind, IPv4 was "obsolete" in 1996 -- almost three years
> before IPv6 was even specified?  Fascinating.  I could be in no way
> mistaken for an IPv4/NAT apologist, but that one's new on me.

IPv4’s address space was known to be too small well before RFC1918.

September 1994 -> RFC 1752
July 1995 -> RFC 1918

RFC 1918 was deployed as a mechanism to extend the usefulness of IPv4 until
IPNG, which became IPv6, was available by reducing the address space pressure on
the registries.

I knew IPv4 didn’t have enough addresses in 1988 when I got my first IPv4 address
allocation.  Anyone with a bit of common sense could see that 4B addresses was
not enough for the Earth.  It was just a matter of time before it would need to
be replaced.

>> Stop making excuses and let's fix the network
> If you want to "fix the network," tolerate neither incompetence or sloth
> from its operators.  Educate the former.  Encourage the latter.
> -- 
> . ___ ___  .   .  ___
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> .  _\_ /__ |-\ |-\ \__

Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742              INTERNET: marka at

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