<s>
A	O
broadcast	O
address	O
is	O
a	O
network	B-Protocol
address	I-Protocol
used	O
to	O
transmit	O
to	O
all	O
devices	O
connected	O
to	O
a	O
multiple-access	O
communications	O
network	O
.	O
</s>
<s>
In	O
contrast	O
,	O
a	O
multicast	B-Protocol
address	I-Protocol
is	O
used	O
to	O
address	O
a	O
specific	O
group	O
of	O
devices	O
,	O
and	O
a	O
unicast	B-Protocol
address	I-Protocol
is	O
used	O
to	O
address	O
a	O
single	O
device	O
.	O
</s>
<s>
For	O
network	B-Application
layer	I-Application
communications	O
,	O
a	O
broadcast	O
address	O
may	O
be	O
a	O
specific	O
IP	B-Protocol
address	I-Protocol
.	O
</s>
<s>
At	O
the	O
data	B-Protocol
link	I-Protocol
layer	I-Protocol
on	O
Ethernet	O
networks	O
,	O
it	O
is	O
a	O
specific	O
MAC	O
address	O
.	O
</s>
<s>
In	O
Internet	B-Protocol
Protocol	I-Protocol
version	I-Protocol
4	I-Protocol
(	O
IPv4	B-Protocol
)	O
networks	O
,	O
broadcast	O
addresses	O
are	O
special	O
values	O
in	O
the	O
host-identification	O
part	O
of	O
an	O
IP	B-Protocol
address	I-Protocol
.	O
</s>
<s>
The	O
later	O
introduction	O
of	O
subnets	B-Protocol
and	O
Classless	B-Protocol
Inter-Domain	I-Protocol
Routing	I-Protocol
changed	O
this	O
slightly	O
,	O
so	O
that	O
the	O
all-ones	O
host	B-Protocol
address	I-Protocol
of	O
each	O
subnet	B-Protocol
is	O
that	O
subnet	B-Protocol
's	O
broadcast	O
address	O
.	O
</s>
<s>
The	O
broadcast	O
address	O
for	O
any	O
IPv4	B-Protocol
host	O
can	O
be	O
obtained	O
by	O
taking	O
the	O
bit	O
complement	O
(	O
bitwise	O
NOT	O
)	O
of	O
the	O
subnet	B-Protocol
mask	I-Protocol
and	O
then	O
performing	O
a	O
bitwise	O
OR	O
operation	O
with	O
the	O
host	O
's	O
IP	B-Protocol
address	I-Protocol
.	O
</s>
<s>
A	O
shortcut	O
to	O
this	O
process	O
(	O
for	O
common	O
masks	O
using	O
only	O
0	O
and	O
1	O
bit	O
placements	O
)	O
is	O
to	O
simply	O
take	O
the	O
host	O
's	O
IP	B-Protocol
address	I-Protocol
and	O
set	O
all	O
bits	O
in	O
the	O
host	O
identifier	O
portion	O
of	O
the	O
address	O
(	O
any	O
bit	O
positions	O
which	O
hold	O
a	O
0	O
in	O
the	O
subnet	B-Protocol
mask	I-Protocol
)	O
to	O
1	O
.	O
</s>
<s>
As	O
shown	O
in	O
the	O
example	O
below	O
,	O
in	O
order	O
to	O
calculate	O
the	O
broadcast	O
address	O
to	O
transmit	O
a	O
packet	O
to	O
an	O
entire	O
IPv4	B-Protocol
subnet	B-Protocol
using	O
the	O
private	B-Protocol
IP	I-Protocol
address	I-Protocol
space	O
,	O
which	O
has	O
the	O
subnet	B-Protocol
mask	I-Protocol
,	O
the	O
broadcast	O
address	O
is	O
calculated	O
as	O
bitwise	O
ORed	O
with	O
=	O
.	O
</s>
<s>
+Broadcast	O
address	O
derivation	O
example	O
Network	O
IP	B-Protocol
address	I-Protocol
breakdown	O
for	O
Binary	O
form	O
Dot-decimal	O
notation	O
In	O
bold	O
below	O
is	O
shown	O
the	O
host	O
part	O
(	O
suffix	O
)	O
of	O
the	O
IP	B-Protocol
address	I-Protocol
,	O
with	O
the	O
network	B-Protocol
address	I-Protocol
prefix	O
being	O
the	O
non-bold	O
bits	O
to	O
its	O
left	O
.	O
</s>
<s>
To	O
obtain	O
the	O
broadcast	O
address	O
,	O
the	O
host	O
bits	O
get	O
set	O
to	O
all	O
1	O
's	O
,	O
while	O
the	O
network	B-Protocol
address	I-Protocol
prefix	O
bits	O
remain	O
intact	O
.	O
</s>
<s>
Network	O
IP	B-Protocol
Address	I-Protocol
10101100.00010000.00000000.00000000	O
172.16.0.0	B-Protocol
2	O
.	O
</s>
<s>
Subnet	B-Protocol
Mask	I-Protocol
,	O
or	O
just	O
"	O
Netmask	B-Protocol
"	O
for	O
short	O
(	O
The	O
'	O
/12	O
'	O
in	O
the	O
IP	B-Protocol
address	I-Protocol
in	O
this	O
case	O
means	O
only	O
the	O
left-most	O
12	O
bits	O
are	O
1s	O
,	O
as	O
shown	O
here	O
.	O
</s>
<s>
This	O
reserves	O
the	O
left	O
12	O
bits	O
for	O
the	O
network	B-Protocol
address	I-Protocol
(	O
prefix	O
)	O
and	O
the	O
right	O
32	O
-	O
12	O
=	O
20	O
bits	O
for	O
the	O
host	B-Protocol
address	I-Protocol
(	O
suffix	O
)	O
.	O
)	O
</s>
<s>
Bit	O
Complement	O
(	O
Bitwise	O
NOT	O
)	O
of	O
the	O
Subnet	B-Protocol
Mask	I-Protocol
00000000.00001111.11111111.11111111	O
0.15.255.255	O
4	O
.	O
</s>
<s>
Network	O
IP	B-Protocol
Address	I-Protocol
and	O
3	O
.	O
</s>
<s>
Bit	O
Complement	O
of	O
the	O
Subnet	B-Protocol
Mask	I-Protocol
.	O
</s>
<s>
This	O
makes	O
the	O
broadcast	O
address	O
the	O
largest	O
possible	O
IP	B-Protocol
address	I-Protocol
(	O
and	O
host	B-Protocol
address	I-Protocol
,	O
since	O
the	O
host	B-Protocol
address	I-Protocol
portion	O
is	O
all	O
1s	O
)	O
for	O
any	O
given	O
network	B-Protocol
address	I-Protocol
.	O
)	O
</s>
<s>
A	O
special	O
definition	O
exists	O
for	O
the	O
IP	B-Protocol
address	I-Protocol
.	O
</s>
<s>
IP	O
broadcasts	O
are	O
used	O
by	O
BOOTP	B-Device
and	O
DHCP	B-Protocol
clients	O
to	O
find	O
and	O
send	O
requests	O
to	O
their	O
respective	O
servers	O
.	O
</s>
<s>
Internet	B-Protocol
Protocol	I-Protocol
version	I-Protocol
6	I-Protocol
(	O
IPv6	B-Protocol
)	O
does	O
not	O
implement	O
this	O
method	O
of	O
broadcast	O
,	O
and	O
therefore	O
does	O
not	O
define	O
broadcast	O
addresses	O
.	O
</s>
<s>
Instead	O
,	O
IPv6	B-Protocol
uses	O
multicast	B-Protocol
addressing	O
to	O
the	O
all-hosts	O
multicast	B-Protocol
group	O
.	O
</s>
<s>
No	O
IPv6	B-Protocol
protocols	O
are	O
defined	O
to	O
use	O
the	O
all-hosts	O
address	O
,	O
though	O
;	O
instead	O
,	O
they	O
send	O
and	O
receive	O
on	O
particular	O
link-local	O
multicast	B-Protocol
addresses	O
.	O
</s>
<s>
This	O
results	O
in	O
higher	O
efficiency	O
because	O
network	O
hosts	O
can	O
filter	O
traffic	O
based	O
on	O
multicast	B-Protocol
address	I-Protocol
and	O
do	O
not	O
need	O
to	O
process	O
all	O
broadcasts	O
or	O
all-hosts	O
multicasts	O
.	O
</s>
<s>
Broadcast	O
is	O
possible	O
also	O
on	O
the	O
underlying	O
data	B-Protocol
link	I-Protocol
layer	I-Protocol
in	O
Ethernet	O
networks	O
.	O
</s>
<s>
Ethernet	O
broadcasts	O
are	O
used	O
,	O
among	O
other	O
purposes	O
,	O
by	O
Address	O
Resolution	O
Protocol	O
to	O
resolve	O
IP	B-Protocol
addresses	I-Protocol
to	O
MAC	O
addresses	O
.	O
</s>
<s>
Internetwork	B-Protocol
Packet	I-Protocol
Exchange	I-Protocol
(	O
IPX	B-Protocol
)	O
allows	O
broadcast	O
.	O
</s>
<s>
The	O
AppleTalk	B-Application
protocol	O
allows	O
broadcast	O
.	O
</s>
