<s>
Snort	B-Language
is	O
a	O
free	B-Application
open	B-Application
source	I-Application
network	O
intrusion	O
detection	O
system	O
(	O
IDS	O
)	O
and	O
intrusion	O
prevention	O
system	O
(	O
IPS	O
)	O
created	O
in	O
1998	O
by	O
Martin	O
Roesch	O
,	O
founder	O
and	O
former	O
CTO	O
of	O
Sourcefire	O
.	O
</s>
<s>
Snort	B-Language
is	O
now	O
developed	O
by	O
Cisco	O
,	O
which	O
purchased	O
Sourcefire	O
in	O
2013	O
.	O
</s>
<s>
In	O
2009	O
,	O
Snort	B-Language
entered	O
InfoWorld	O
's	O
Open	B-Application
Source	I-Application
Hall	O
of	O
Fame	O
as	O
one	O
of	O
the	O
"	O
greatest	O
[	O
pieces	O
of ]	O
open	B-Application
source	I-Application
software	I-Application
of	O
all	O
time	O
"	O
.	O
</s>
<s>
Snort	B-Language
's	O
open-source	B-Application
network-based	O
intrusion	O
detection/prevention	O
system	O
(	O
IDS/IPS	O
)	O
has	O
the	O
ability	O
to	O
perform	O
real-time	O
traffic	O
analysis	O
and	O
packet	B-Protocol
logging	I-Protocol
on	O
Internet	B-Protocol
Protocol	I-Protocol
(	O
IP	O
)	O
networks	O
.	O
</s>
<s>
Snort	B-Language
performs	O
protocol	O
analysis	O
,	O
content	O
searching	O
and	O
matching	O
.	O
</s>
<s>
The	O
program	O
can	O
also	O
be	O
used	O
to	O
detect	O
probes	O
or	O
attacks	O
,	O
including	O
,	O
but	O
not	O
limited	O
to	O
,	O
operating	B-Protocol
system	I-Protocol
fingerprinting	I-Protocol
attempts	O
,	O
semantic	B-Protocol
URL	I-Protocol
attacks	I-Protocol
,	O
buffer	B-General_Concept
overflows	I-General_Concept
,	O
server	B-Operating_System
message	I-Operating_System
block	I-Operating_System
probes	O
,	O
and	O
stealth	O
port	O
scans	O
.	O
</s>
<s>
Snort	B-Language
can	O
be	O
configured	O
in	O
three	O
main	O
modes	O
:	O
1	O
.	O
sniffer	O
,	O
2	O
.	O
packet	O
logger	O
,	O
and	O
3	O
.	O
network	O
intrusion	O
detection	O
.	O
</s>
<s>
There	O
are	O
several	O
third-party	O
tools	O
interfacing	O
Snort	B-Language
for	O
administration	O
,	O
reporting	O
,	O
performance	O
and	O
log	O
analysis	O
:	O
</s>
