Documentation of localnet bridge mapping is inaccurate and too limiting. It does not do enough to prevent customers from shooting down their clusters. And on the other hand, its wording bans some of the supported network configurations from being used, causing issues to the support team.

    4.14+

    Docs

    1. Go to https://docs.openshift.com/container-platform/4.16/networking/multiple_networks/configuring-additional-network.html#configuring-additional-network_configuration-additional-network-interface
    

    When attaching an additional network ...
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    When attaching an additional network, you can either use the existing br-ex bridge or create a new bridge. Which approach to use depends on your specific network infrastructure.

    When creating a new bridge, a bonding could be configured to provide link redundancy. In some cases, VLAN interfaces may be required in order to share access to an interface already used by br-ex.

    When reconfiguring the host network, it is critical to avoid reconfiguration of the br-ex bridge. If you fail to follow these rules, your cluster network may stop working correctly:
    * The bridge br-ex must not be reconfigured
    * The southbound port of br-ex must stay attached to the bridge. Connecting this interface to another bridge or bonding, or changing its configuration* would detach the port from br-ex

    NOTE: * bond options changes are supported

    This should solve a common issue our customers and support teams struggle with. See https://issues.redhat.com/browse/OCPBUGS-36674 to find more info about the motivation