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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 pop-
       ulated /etc/hostid, or on machines that do not use loader(8).

       ether_gen_addr can fail to derive a MAC address due to  memory  alloca-
       tion  failure,  or because the hostid has not been populated.  In these
       cases, a	locally-administered unicast MAC address will be randomly gen-
       erated and returned 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	14.3			 June 1, 2021		     ETHER_GEN_ADDR(9)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=ether_gen_addr&sektion=9&manpath=FreeBSD+14.3-RELEASE+and+Ports>

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