Currently, IPv6 CIDRs are rejected during install-config validation. This was changed in master/4.4 via https://github.com/openshift/installer/pull/2829
See https://github.com/openshift/installer/pull/3029
Verify this bug with registry.svc.ci.openshift.org/ocp/release:4.3.0-0.nightly-2020-02-21-003712 Set the following parameters in install-config.yaml networking: clusterNetwork: - cidr: fd01::/48 hostPrefix: 64 machineNetwork: - cidr: 10.0.0.0/16 - cidr: fd00::/48 networkType: OVNKubernetes serviceNetwork: - fd02::/112 With OPENSHIFT_INSTALL_AZURE_EMULATE_SINGLESTACK_IPV6=true, start the installation. Installer could create the expected subnets with ipv6 address CIDR. Move this bug to verified.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2020:0676
ipv6 is only supported on baremetal - no support for GCP / AWS / Azure. FATAL failed to fetch Metadata: failed to load asset "Install Config": invalid "install-config.yaml" file: networking: Invalid value: "IPv6": single-stack IPv6 is not supported for this platform