<s>
Monitor	B-Protocol
mode	I-Protocol
,	O
or	O
RFMON	B-Protocol
(	O
Radio	O
Frequency	O
MONitor	O
)	O
mode	O
,	O
allows	O
a	O
computer	O
with	O
a	O
wireless	B-General_Concept
network	I-General_Concept
interface	I-General_Concept
controller	I-General_Concept
(	O
WNIC	O
)	O
to	O
monitor	O
all	O
traffic	O
received	O
on	O
a	O
wireless	O
channel	O
.	O
</s>
<s>
Unlike	O
promiscuous	B-Protocol
mode	I-Protocol
,	O
which	O
is	O
also	O
used	O
for	O
packet	B-Protocol
sniffing	I-Protocol
,	O
monitor	B-Protocol
mode	I-Protocol
allows	O
packets	O
to	O
be	O
captured	O
without	O
having	O
to	O
associate	O
with	O
an	O
access	B-Device
point	I-Device
or	O
ad	B-Protocol
hoc	I-Protocol
network	I-Protocol
first	O
.	O
</s>
<s>
Monitor	B-Protocol
mode	I-Protocol
only	O
applies	O
to	O
wireless	O
networks	O
,	O
while	O
promiscuous	B-Protocol
mode	I-Protocol
can	O
be	O
used	O
on	O
both	O
wired	O
and	O
wireless	O
networks	O
.	O
</s>
<s>
Monitor	B-Protocol
mode	I-Protocol
is	O
one	O
of	O
the	O
eight	O
modes	O
that	O
802.11	O
wireless	B-General_Concept
adapter	I-General_Concept
can	O
operate	O
in	O
:	O
Master	O
(	O
acting	O
as	O
an	O
access	B-Device
point	I-Device
)	O
,	O
Managed	O
(	O
client	O
,	O
also	O
known	O
as	O
station	O
)	O
,	O
Ad	B-General_Concept
hoc	I-General_Concept
,	O
Repeater	O
,	O
Mesh	O
,	O
Wi-Fi	O
Direct	O
,	O
TDLS	B-Protocol
and	O
Monitor	B-Protocol
mode	I-Protocol
.	O
</s>
<s>
Uses	O
for	O
monitor	B-Protocol
mode	I-Protocol
include	O
:	O
geographical	O
packet	B-Protocol
analysis	I-Protocol
,	O
observing	O
of	O
widespread	O
traffic	O
and	O
acquiring	O
knowledge	O
of	O
Wi-Fi	O
technology	O
through	O
hands-on	O
experience	O
.	O
</s>
<s>
It	O
is	O
especially	O
useful	O
for	O
auditing	O
unsecure	O
channels	O
(	O
such	O
as	O
those	O
protected	O
with	O
WEP	B-Protocol
)	O
.	O
</s>
<s>
Monitor	B-Protocol
mode	I-Protocol
can	O
also	O
be	O
used	O
to	O
help	O
design	O
Wi-Fi	O
networks	O
.	O
</s>
<s>
Software	O
such	O
as	O
KisMAC	B-Language
or	O
Kismet	B-Protocol
,	O
in	O
combination	O
with	O
packet	B-Protocol
analyzers	I-Protocol
that	O
can	O
read	O
pcap	B-Language
files	O
,	O
provide	O
a	O
user	O
interface	O
for	O
passive	O
wireless	O
network	O
monitoring	O
.	O
</s>
<s>
Usually	O
the	O
wireless	B-General_Concept
adapter	I-General_Concept
is	O
unable	O
to	O
transmit	O
in	O
monitor	B-Protocol
mode	I-Protocol
and	O
is	O
restricted	O
to	O
a	O
single	O
wireless	O
channel	O
,	O
though	O
this	O
is	O
dependent	O
on	O
the	O
wireless	B-General_Concept
adapter	I-General_Concept
's	O
driver	O
,	O
its	O
firmware	O
,	O
and	O
features	O
of	O
its	O
chipset	O
.	O
</s>
<s>
Also	O
,	O
in	O
monitor	B-Protocol
mode	I-Protocol
the	O
adapter	O
does	O
not	O
check	O
to	O
see	O
if	O
the	O
cyclic	O
redundancy	O
check	O
(	O
CRC	O
)	O
values	O
are	O
correct	O
for	O
packets	O
captured	O
,	O
so	O
some	O
captured	O
packets	O
may	O
be	O
corrupted	O
.	O
</s>
<s>
The	O
Microsoft	B-Application
Windows	I-Application
Network	B-Application
Driver	I-Application
Interface	I-Application
Specification	I-Application
(	O
NDIS	O
)	O
API	O
has	O
supported	O
extensions	O
for	O
monitor	B-Protocol
mode	I-Protocol
since	O
NDIS	O
version	O
6	O
,	O
first	O
available	O
in	O
Windows	B-Application
Vista	I-Application
.	O
</s>
<s>
Monitor	B-Protocol
mode	I-Protocol
support	O
in	O
NDIS	O
6	O
is	O
an	O
optional	O
feature	O
and	O
may	O
or	O
may	O
not	O
be	O
implemented	O
in	O
the	O
client	O
adapter	O
driver	O
.	O
</s>
<s>
In	O
many	O
cases	O
,	O
monitor	B-Protocol
mode	I-Protocol
support	O
is	O
not	O
properly	O
implemented	O
by	O
the	O
vendor	O
.	O
</s>
<s>
For	O
versions	O
of	O
Windows	O
prior	O
to	O
Windows	B-Application
Vista	I-Application
,	O
some	O
packet	B-Protocol
analyzer	I-Protocol
applications	O
such	O
as	O
Wildpackets	B-Protocol
 '	O
OmniPeek	B-Protocol
and	O
TamoSoft	O
's	O
CommView	B-Protocol
for	O
WiFi	O
provide	O
their	O
own	O
device	O
drivers	O
to	O
support	O
monitor	B-Protocol
mode	I-Protocol
.	O
</s>
<s>
Linux	O
's	O
interfaces	O
for	O
802.11	O
drivers	O
support	O
monitor	B-Protocol
mode	I-Protocol
and	O
many	O
drivers	O
offer	O
that	O
support	O
.	O
</s>
<s>
STA	O
drivers	O
(	O
Ralink	O
,	O
Broadcom	O
)	O
and	O
every	O
other	O
manufacturer	O
’s	O
provided	O
driver	O
does	O
n’t	O
support	O
monitor	B-Protocol
mode	I-Protocol
.	O
</s>
<s>
FreeBSD	B-Operating_System
,	O
NetBSD	B-Device
,	O
OpenBSD	B-Operating_System
,	O
and	O
DragonFly	B-Application
BSD	I-Application
also	O
provide	O
an	O
interface	O
for	O
802.11	O
drivers	O
that	O
supports	O
monitor	B-Protocol
mode	I-Protocol
,	O
and	O
many	O
drivers	O
for	O
those	O
operating	O
systems	O
support	O
monitor	B-Protocol
mode	I-Protocol
as	O
well	O
.	O
</s>
<s>
In	O
Mac	O
OS	O
X	O
10.4	O
and	O
later	O
releases	O
,	O
the	O
drivers	O
for	O
AirPort	B-Device
Extreme	I-Device
network	O
adapters	O
allow	O
the	O
adapter	O
to	O
be	O
put	O
into	O
monitor	B-Protocol
mode	I-Protocol
.	O
</s>
<s>
Libpcap	B-Language
1.0.0	O
and	O
later	O
provides	O
an	O
API	O
to	O
select	O
monitor	B-Protocol
mode	I-Protocol
when	O
capturing	O
on	O
those	O
operating	O
systems	O
.	O
</s>
