Some customers/Partners need to set cluster network MTU at deployment time using Agent-Based Installer in order to specify cluster network within extra MTU buffer to avoid future MTU update in day2 (MTU update in day2 require a minimum of 2 reboots). Today MTU is define by cluster network operator at deployment time based on MTU configured on machine network interface. By setting the cluster network MTU at deployment time, CNO will set this value instead of calculate/define cluster network mtu value based on machine network MTU (cluster network MTU must be lower than machine network MTU by 100 bytes (ovn overhead) if ipsec not enabled). We do not have in ABI documentation, a note explaining how to set this cluster network MTU as for machine network MTU at deployment time. We wrote a KB article for the procedure:  https://access.redhat.com/node/7134465/draft

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