// Module included in the following assemblies:
//
// * microshift_networking/microshift-disconnected-network-config.adoc

:_mod-docs-content-type: CONCEPT
[id="microshift-disconnected-host-preparation_{context}"]
= Preparing networking for fully disconnected hosts

[role="_abstract"]
To run {microshift-short} on a fully disconnected host with no external network connectivity, you prepare a persistent hostname, loopback IP addressing, DNS, and `/etc/hosts` entries before you apply {microshift-short} network configuration.

Typically this means that the device does not have an attached network interface controller (NIC) to provide a subnet. These steps can also be completed on a host with a NIC that is removed after setup. You can also automate these steps on a host that does not have a NIC by using the `%post` phase of a Kickstart file.

[IMPORTANT]
====
Configuring networking settings for disconnected environments is necessary because {microshift-short} requires a network device to support node communication. To meet this requirement, you must configure {microshift-short} networking settings to use the "fake" IP address you assign to the system loopback device during setup.
====

[id="microshift-disconnected-host-procedure-summary_{context}"]
== Procedure summary

To run {microshift-short} on a disconnected host, the following steps are required:

Prepare the host::
* Stop {microshift-short} if it is currently running and clean up changes the service has made to the network.
* Set a persistent hostname.
* Add a “fake” IP address on the loopback interface.
* Configure DNS to use the fake IP as local name server.
* Add an entry for the hostname to `/etc/hosts`.

Update the {microshift-short} configuration::
* Define the `nodeIP` parameter as the new loopback IP address.
* Set the `.node.hostnameOverride` parameter to the persistent hostname.

For the changes to take effect::
* Disable the default NIC if attached.
* Restart the host or device.

After starting, {microshift-short} runs using the loopback device for intra-node communication.
