第8章 Configuring network settings for fully disconnected hosts
Learn how to apply networking customization and settings to run MicroShift on fully disconnected hosts. A disconnected host should be the Red Hat Enterprise Linux (RHEL) operating system, versions 9.0+, whether real or virtual, that runs without network connectivity.
8.1. Preparing networking for fully disconnected hosts
Use the procedure that follows to start and run MicroShift nodes on devices running fully disconnected operating systems. A MicroShift host is considered fully disconnected if it has no external network connectivity.
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.
Configuring networking settings for disconnected environments is necessary because MicroShift requires a network device to support node communication. To meet this requirement, you must configure MicroShift networking settings to use the "fake" IP address you assign to the system loopback device during setup.
8.1.1. Procedure summary
To run MicroShift on a disconnected host, the following steps are required:
- Prepare the host
- Stop MicroShift 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 configuration
-
Define the
nodeIPparameter as the new loopback IP address. -
Set the
.node.hostnameOverrideparameter to the persistent hostname.
-
Define the
- For the changes to take effect
- Disable the default NIC if attached.
- Restart the host or device.
After starting, MicroShift runs using the loopback device for intra-node communication.
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