<s>
dig	B-Protocol
is	O
a	O
network	O
administration	O
command-line	B-Application
tool	I-Application
for	O
querying	O
the	O
Domain	B-Protocol
Name	I-Protocol
System	I-Protocol
(	O
DNS	B-Protocol
)	O
.	O
</s>
<s>
dig	B-Protocol
(	O
Domain	B-Protocol
Information	I-Protocol
Groper	I-Protocol
)	O
is	O
useful	O
for	O
network	O
troubleshooting	O
and	O
for	O
educational	O
purposes	O
.	O
</s>
<s>
It	O
can	O
operate	O
based	O
on	O
command	B-Application
line	I-Application
option	O
and	O
flag	O
arguments	O
,	O
or	O
in	O
batch	O
mode	O
by	O
reading	O
requests	O
from	O
an	O
operating	O
system	O
file	O
.	O
</s>
<s>
When	O
a	O
specific	O
name	B-Protocol
server	I-Protocol
is	O
not	O
specified	O
in	O
the	O
command	O
invocation	O
,	O
it	O
uses	O
the	O
operating	O
system	O
's	O
default	O
resolver	O
,	O
usually	O
configured	O
in	O
the	O
file	O
resolv.conf	B-Protocol
.	O
</s>
<s>
Without	O
any	O
arguments	O
it	O
queries	O
the	O
DNS	B-Protocol
root	I-Protocol
zone	I-Protocol
.	O
</s>
<s>
dig	B-Protocol
supports	O
Internationalized	B-Language
domain	I-Language
name	I-Language
(	O
IDN	O
)	O
queries	O
.	O
</s>
<s>
dig	B-Protocol
is	O
a	O
component	O
of	O
the	O
domain	B-Protocol
name	I-Protocol
server	I-Protocol
software	O
suite	O
BIND	B-Protocol
.	O
</s>
<s>
dig	B-Protocol
supersedes	O
in	O
functionality	O
older	O
tools	O
,	O
such	O
as	O
nslookup	B-Protocol
and	O
the	O
program	O
host	B-Protocol
;	O
however	O
,	O
the	O
older	O
tools	O
are	O
still	O
used	O
in	O
complementary	O
fashion	O
.	O
</s>
<s>
In	O
this	O
example	O
,	O
dig	B-Protocol
is	O
used	O
to	O
query	O
for	O
any	O
type	O
of	O
record	O
information	O
in	O
the	O
domain	O
example.com	O
:	O
</s>
<s>
The	O
any	O
DNS	B-Protocol
query	I-Protocol
is	O
a	O
special	O
meta	O
query	O
which	O
is	O
now	O
deprecated	O
.	O
</s>
<s>
Since	O
,	O
most	O
public	O
DNS	B-Protocol
servers	I-Protocol
have	O
stopped	O
answering	O
most	O
DNS	B-Protocol
ANY	O
queries	O
usefully	O
.	O
</s>
<s>
If	O
ANY	O
queries	O
do	O
not	O
enumerate	O
multiple	O
records	O
,	O
the	O
only	O
option	O
is	O
to	O
request	O
each	O
record	B-Protocol
type	I-Protocol
(	O
e.g.	O
</s>
<s>
Queries	O
may	O
be	O
directed	O
to	O
designated	O
DNS	B-Protocol
servers	I-Protocol
for	O
specific	O
records	O
;	O
in	O
this	O
example	O
,	O
MX	B-Protocol
records	I-Protocol
:	O
</s>
<s>
dig	B-Protocol
was	O
originally	O
written	O
by	O
Steve	O
Hotz	O
and	O
incorporated	O
into	O
BIND	B-Protocol
4	O
;	O
later	O
it	O
was	O
rewritten	O
by	O
Michael	O
Sawyer	O
,	O
and	O
is	O
maintained	O
by	O
the	O
Internet	O
Systems	O
Consortium	O
as	O
part	O
of	O
BIND	B-Protocol
9	I-Protocol
.	O
</s>
<s>
When	O
originally	O
written	O
,	O
the	O
manual	O
page	O
for	O
dig	B-Protocol
indicated	O
that	O
its	O
name	O
was	O
an	O
acronym	O
for	O
"	O
Domain	B-Protocol
Information	I-Protocol
Groper	I-Protocol
"	O
.	O
</s>
<s>
This	O
expansion	O
was	O
removed	O
in	O
2017	O
;	O
the	O
tool	O
's	O
name	O
is	O
now	O
simply	O
"	O
dig	B-Protocol
"	O
.	O
</s>
