The Department of Work and Pensions, UK has an entire /8 nanog@nanog.org

[bonomi at mail.r-bonomi.com (Robert Bonomi)]

> From: Jo Rhett <jrhett at netconsonance.com>
> Date: Wed, 19 Sep 2012 10:42:30 -0700
> Subject: Re: The Department of Work and Pensions, UK has an entire /8

[[ sneck ]]
>
> And second, have you ever worked on a private intranet that wasn't 
> connected to the internet through a firewall? Skipping oob networks for 
> equipment management, neither have I.

Yes, in fact, I have.  <grin>

In the financial and/or brokerage communities, there are internal networks
with enough 'high value'/sensitive information to justify "air gap"
isolation from the outide world. 

Also, in those industries, there are 'semi-isolated' networks where
all external commnications are mediated through dual-homed _application-
layer_ gateways. No packet-level communications between 'inside' and
'outside'.  The 'inside' apps onl know how to talk to the gateway; server-
side talks only to specific (pre-determined) trusted hosts for the
specific request being processed.  NO 'transparent pass-through' in
either direction.