Document URL: https://docs.openshift.com/container-platform/4.8/installing/installing_bare_metal/installing-bare-metal.html#installation-user-infra-machines-static-network_installing-bare-metal Section Number and Name: Table 11. Networking and bonding options for ISO installations - After "Specify multiple network interfaces by specifying multiple ip= entries" Describe the issue: If a user specify different gateway ip in ip= kernel argument, the NetworkManager could use the additional network gateway to fetch CoreOS rootfs. The additional network does not necessarily host an http and dns server. Therefore, it is necessary while doing multi-NIC installation, additional gateways must be defined separately with rd.core= instead of ip= kernel argument. Suggestions for improvement: If the additional network interface gateway is different from the primary network interface, the default gateway must be the primary network interface. In the next column: The default gateway can be defined as: ip=::10.10.10.254:::: Route for additional network can be defined as: rd.route=20.20.20.0/24:20.20.20.254:enp2s0 Additional information:
I've verified with @micah.abbott that this works with x86 and have added then entry to the table in this PR: https://github.com/openshift/openshift-docs/pull/36250/
Docs are updated PR has been merged