MAC_ADDR syntax

MAC_ADDR $<$hostname$>$ $<$mac_address$>$

This directive can be used for nodes that do not retrieve their hostname from DHCP in an initramfs. If a node boots without a hostname set, the MAC address of every network interface is scanned. If the MAC address of any interface matches the mac_address of a directive, the node's hostname is set from the directive's corresponding hostname parameter.

For this directive to work, any referenced network interface's drivers must have already been loaded. This means the drivers need to be directly compiled into the kernel, loaded from an initramfs, or specified via a ETH_PRELOAD directive.