<s>
A	O
network	B-Protocol
address	I-Protocol
is	O
an	O
identifier	O
for	O
a	O
node	B-Protocol
or	O
host	B-Device
on	O
a	O
telecommunications	O
network	O
.	O
</s>
<s>
Network	O
addresses	O
are	O
designed	O
to	O
be	O
unique	O
identifiers	O
across	O
the	O
network	O
,	O
although	O
some	O
networks	O
allow	O
for	O
local	B-Protocol
,	O
private	B-Protocol
addresses	I-Protocol
,	O
or	O
locally	O
administered	O
addresses	O
that	O
may	O
not	O
be	O
unique	O
.	O
</s>
<s>
Special	O
network	O
addresses	O
are	O
allocated	O
as	O
broadcast	B-Protocol
or	O
multicast	O
addresses	O
.	O
</s>
<s>
In	O
some	O
cases	O
,	O
network	B-Device
hosts	I-Device
may	O
have	O
more	O
than	O
one	O
network	B-Protocol
address	I-Protocol
.	O
</s>
<s>
For	O
example	O
,	O
each	O
network	B-Protocol
interface	I-Protocol
controller	I-Protocol
may	O
be	O
uniquely	O
identified	O
.	O
</s>
<s>
Further	O
,	O
because	O
protocols	O
are	O
frequently	O
layered	B-Architecture
,	O
more	O
than	O
one	O
protocol	O
's	O
network	B-Protocol
address	I-Protocol
can	O
occur	O
in	O
any	O
particular	O
network	O
interface	O
or	O
node	B-Protocol
and	O
more	O
than	O
one	O
type	O
of	O
network	B-Protocol
address	I-Protocol
may	O
be	O
used	O
in	O
any	O
one	O
network	O
.	O
</s>
<s>
Network	O
addresses	O
can	O
be	O
flat	O
addresses	O
which	O
contain	O
no	O
information	O
about	O
the	O
node	B-Protocol
's	O
location	O
in	O
the	O
network	O
(	O
such	O
as	O
a	O
MAC	O
address	O
)	O
,	O
or	O
may	O
contain	O
structure	O
or	O
hierarchical	O
information	O
for	O
the	O
routing	B-Protocol
(	O
such	O
as	O
an	O
IP	B-Protocol
address	I-Protocol
)	O
.	O
</s>
