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ETHER_GEN_ADDR(9)	    Kernel Developer's Manual	       ETHER_GEN_ADDR(9)

NAME
     ether_gen_addr -- generate an arbitrary MAC address for use

SYNOPSIS
     #include <sys/types.h>
     #include <sys/socket.h>
     #include <net/if.h>
     #include <net/if_var.h>
     #include <net/ethernet.h>

     void
     ether_gen_addr(struct ifnet *ifp, struct ether_addr *hwaddr);

DESCRIPTION
     The ether_gen_addr() function generates an arbitrary MAC address for use by
     an ethernet interface that does not have an assigned address.

     By  default, ether_gen_addr attempts to generate a stable MAC address using
     the hostid of the jail that the ifp is being added to.  During early  boot,
     the  hostid  may  not  be	set  on  machines  that  haven't  yet  populated
     /etc/hostid, or on machines that do not use loader(8).

     ether_gen_addr can fail to derive a MAC address due  to  memory  allocation
     failure,  or  because the hostid has not been populated.  In these cases, a
     locally-administered unicast MAC address will be randomly generated and re-
     turned via the hwaddr parameter.

     If ether_gen_addr succeeds, then it  will	return	a  MAC	address  in  the
     FreeBSD Foundation OUI, "58:9c:fc", via the hwaddr parameter.

AUTHORS
     This manual page was written by Kyle Evans <kevans@FreeBSD.org>.

FreeBSD ports 15.quarterly	  June 1, 2021		       ETHER_GEN_ADDR(9)

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<https://man.freebsd.org/cgi/man.cgi?query=ether_gen_addr&sektion=9&manpath=FreeBSD+15.1-RELEASE+and+Ports.quarterly>

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