--dhcp-broadcast[=tag:<tag>[,tag:<tag>]]

(IPv4 only) When all the given tags appear in the tag set, always use broadcast to communicate with the host when it is unconfigured. It is permissible to supply no tags, in which case this is unconditional. Most DHCP clients which need broadcast replies set a flag in their requests so that this happens automatically, some old BOOTP clients do not.