Air Gap'd network.

The concept of not having a physical connection from Control Systems and the rest of the world. Interesting concept, isn't it?

The term is mostly used in SCADA systems. You have a gap between your control system and the rest of the world so nothing can attack your infrastructure.

Great name, great concept, but is it real?  How can you protect your infrastructure so tightly when there should be a complete gap from public to private side? No connectivity at all.  Does it work ?  Does it exist?  I'm sure it does in various formats

Lets look at WikiPedia says:

An air gap or air wall^[1] is a security measure often taken for computers and computer networks that must be extraordinarily secure. It consists of ensuring that a secure network is completely physically, electrically, and electromagnetically isolated from insecure networks, such as the public Internet or an insecure local area network. Limitations imposed on devices used in these environments may include a ban on wireless connections to or from the secure network or similar restrictions on EM leakage from the secure network through the use of TEMPEST or a faraday cage. It is most recognizable in the time-honored configuration known as "sneaker-net" where the only connection between two devices or networks is via a human being providing media-switching, i.e.; floppies, CDs, or USB drives. The term derives from the notion that one must put on sneakers and walk to transfer data.

Sneaker Net?  Does anyone remember how well this worked?  It was a term used BEFORE networks were readily available for the average company and person.  As explained, you physically had to carry a copy of whatever you wanted to share to those you wanted to share it with.  Did it work?  Does anyone remember the use of 5-1/4 floppies and how reliable they were?  In many instances they failed, because companies bought sub standard floppies. Or worse, someone rubbed the outer shell to the disk while taking it to their destination.  They became scratched and useless.

Now I can see the need for some "top secret" organizations disconnecting itself from the Internet completely.  But does this happen regularly for your average company or organization?  No.  Because users demand Internet connectivity. A closed network limits creativity some might argue as well.

To take more from WikiPedia for examples:

Examples of the types of networks or systems that may be air gapped include:

• Military/governmental computer networks/systems^[3]
• Life-critical systems, such as:
  • Controls of nuclear power plants;
  • Computers used in aviation^[4], such as FADECs and avionics;
  • Computerized medical equipment.

Does this actually happen? Does it ?  I don't think so, again because users demand connectivity to the web.

Click on the link to read a great post on the fantasy of the air gap

Take a real close look at the diagram presented.  Real close look.   Can you spot the Air Gap ?