draft of airgap instructions

docs/install-upgrade/overview.md

@@ -65,29 +65,73 @@ More details on configuring the Fabric are available in the [Configuration](./co
 
 ## Install Control Node
 
-Control Node installation is fully air-gapped and doesn't require Internet access. This control node should be given a static IP address. Either a lease or statically assigned. 
+### Connected Instructions
+This control node should be given a static IP address. Either a lease or statically assigned. 
 
-Download the [latest stable Flatcar Container Linux ISO][Flatcar ISO] and boot into it (using IPMI attaching media, USB
-stick or any other way).
+1. Download the [latest stable Flatcar Container Linux ISO ~400MiB][Flatcar ISO]
 
 [Flatcar ISO]: https://stable.release.flatcar-linux.net/amd64-usr/current/flatcar_production_iso_image.iso
 
-Once you've booted into the Flatcar installer, upload the file `ignition.json` built during the previous step to the
+1. Bios boot the control node using the ISO, via virtual media, USB, or other way.
+
+1. Once the control node has booted it will auto login to a shell
+
+1. Upload the file `ignition.json` built during the previous step to the
 system and run the Flatcar installation:
 
 ```bash
 sudo flatcar-install -d /dev/sda -i ignition.json
 ```
 
 Where `/dev/sda` is a disk you want to install Control Node to and `ignition.json` is the `control-os/ignition.json`
-file from previous step uploaded to the Flatcar installer.
+file from previous step uploaded to the Flatcar installer. This installer reaches out to the publically available images to download, verify and install flatcar to the given disk.
+
+The installation is finished when you see a message similar to the following:
+
+```shell
+Installing Ignition config ignition.json...
+Success! Flatcar Container Linux stable 3510.2.6 is installed on /dev/sda
+```
+
+[Move on to the next step](#continue-forward)
+
+### Air Gapped Instructions
+Control Node installation is fully air-gapped and doesn't require Internet access. A static IP is still needed as command and control communications between the switches and controller use IP. The instructions are similar to above you need to install 
+
+1. Download the [latest stable Flatcar Container Linux ISO ~400MiB][Flatcar ISO] and bios boot into it (using IPMI attaching media, USB
+stick or any other way).
+
+[Flatcar ISO]: https://stable.release.flatcar-linux.net/amd64-usr/current/flatcar_production_iso_image.iso
+
+1. Download the [latest stable Flatcar Container Linux Image ~500MiB][Flatcar Image] and copy that file to media that can be attached to the control node.
+[Flatcar Image]: https://stable.release.flatcar-linux.net/amd64-usr/current/flatcar_production_image.bin.bz2
+
+1. Copy the `control-os/ignition.json` file to the media from the above step.
+
+1. Bios boot the control node using the iso from above.
+
+1. Once the control node has booted, it will auto-login to a shell.
+
+1. Attach the media containing both the container image file and the ignition file to the booted control node.
+
+1. Uncompress the image `bunzip -d ./path/to/flatcar_production_image.bin.bz2`, if you want to keep the compressed image use the `-k` flag.
+
+```bash
+sudo flatcar-install -d /dev/sda -i ignition.json -f flatcar_production_image.bin
+```
+
+Where `/dev/sda` is a disk you want to install Control Node to and `ignition.json` is the `control-os/ignition.json`
+file from previous step uploaded to the Flatcar installer. By providing an image to the installer, no public internet connections will be attemtped.
 
 The installation is finished when you see a message similar to the following:
 
 ```shell
 Installing Ignition config ignition.json...
 Success! Flatcar Container Linux stable 3510.2.6 is installed on /dev/sda
 ```
+[Move on to the next step](#continue-forward)
+
+### Continue Forward
 
 Once the installation is finished, reboot the machine and wait for it to boot into the installed Flatcar Linux.