Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<!--
 - Copyright (C) 2015-2019 Internet Systems Consortium, Inc. ("ISC")
 - 
 - This Source Code Form is subject to the terms of the Mozilla Public
 - License, v. 2.0. If a copy of the MPL was not distributed with this
 - file, You can obtain one at http://mozilla.org/MPL/2.0/.
-->
<html lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>mdig</title>
<meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="refentry">
<a name="man.mdig"></a><div class="titlepage"></div>
  
  
  
  <div class="refnamediv">
<h2>Name</h2>
<p>
    <span class="application">mdig</span>
     &#8212; DNS pipelined lookup utility
  </p>
</div>

  

  <div class="refsynopsisdiv">
<h2>Synopsis</h2>
    <div class="cmdsynopsis"><p>
      <code class="command">mdig</code> 
       {@server}
       [<code class="option">-f <em class="replaceable"><code>filename</code></em></code>]
       [<code class="option">-h</code>]
       [<code class="option">-v</code>]
       [
	[<code class="option">-4</code>]
	 |  [<code class="option">-6</code>]
      ]
       [<code class="option">-m</code>]
       [<code class="option">-b <em class="replaceable"><code>address</code></em></code>]
       [<code class="option">-p <em class="replaceable"><code>port#</code></em></code>]
       [<code class="option">-c <em class="replaceable"><code>class</code></em></code>]
       [<code class="option">-t <em class="replaceable"><code>type</code></em></code>]
       [<code class="option">-i</code>]
       [<code class="option">-x <em class="replaceable"><code>addr</code></em></code>]
       [plusopt...]
    </p></div>

    <div class="cmdsynopsis"><p>
      <code class="command">mdig</code> 
       {-h}
    </p></div>

    <div class="cmdsynopsis"><p>
      <code class="command">mdig</code> 
       [@server]
       {global-opt...}
       {
         {local-opt...}
          {query}
      ...}
    </p></div>
  </div>

  <div class="refsection">
<a name="id-1.7"></a><h2>DESCRIPTION</h2>

    <p><span class="command"><strong>mdig</strong></span>
      is a multiple/pipelined query version of <span class="command"><strong>dig</strong></span>:
      instead of waiting for a response after sending each query,
      it begins by sending all queries. Responses are displayed in
      the order in which they are received, not in the order the
      corresponding queries were sent.
    </p>

    <p>
      <span class="command"><strong>mdig</strong></span> options are a subset of the
      <span class="command"><strong>dig</strong></span> options, and are divided into "anywhere
      options" which can occur anywhere, "global options" which must
      occur before the query name (or they are ignored with a warning),
      and "local options" which apply to the next query on the command
      line.
    </p>

    <p>
      The {@server} option is a mandatory global
      option.  It is the name or IP address of the name server to query.
      (Unlike <span class="command"><strong>dig</strong></span>, this value is not retrieved from
      <code class="filename">/etc/resolv.conf</code>.)  It can be an IPv4 address
      in dotted-decimal notation, an IPv6 address in colon-delimited
      notation, or a hostname.  When the supplied
      <em class="parameter"><code>server</code></em> argument is a hostname,
      <span class="command"><strong>mdig</strong></span> resolves that name before querying
      the name server.
    </p>

    <p><span class="command"><strong>mdig</strong></span>
      provides a number of query options which affect
      the way in which lookups are made and the results displayed.  Some of
      these set or reset flag bits in the query header, some determine which
      sections of the answer get printed, and others determine the timeout
      and retry strategies.
    </p>

    <p>
      Each query option is identified by a keyword preceded by a plus
      sign (<code class="literal">+</code>).  Some keywords set or reset an
      option.  These may be preceded by the string <code class="literal">no</code>
      to negate the meaning of that keyword.  Other keywords assign
      values to options like the timeout interval.  They have the
      form <code class="option">+keyword=value</code>.
    </p>
  </div>

  <div class="refsection">
<a name="id-1.8"></a><h2>ANYWHERE OPTIONS</h2>


    <p>
      The <code class="option">-f</code> option makes <span class="command"><strong>mdig</strong></span>
      operate in batch mode by reading a list of lookup requests to
      process from the file <em class="parameter"><code>filename</code></em>.  The file
      contains a number of queries, one per line.  Each entry in the
      file should be organized in the same way they would be presented
      as queries to <span class="command"><strong>mdig</strong></span> using the command-line interface.
    </p>

    <p>
      The <code class="option">-h</code> causes <span class="command"><strong>mdig</strong></span> to
      print the detailed help with the full list of options and exit.
    </p>

    <p>
      The <code class="option">-v</code> causes <span class="command"><strong>mdig</strong></span> to
      print the version number and exit.
    </p>
  </div>

  <div class="refsection">
<a name="id-1.9"></a><h2>GLOBAL OPTIONS</h2>


    <p>
      The <code class="option">-4</code> option forces <span class="command"><strong>mdig</strong></span> to
      only use IPv4 query transport.
    </p>

    <p>
      The <code class="option">-6</code> option forces <span class="command"><strong>mdig</strong></span> to
      only use IPv6 query transport.
    </p>

    <p>
      The <code class="option">-b</code> option sets the source IP address of the
      query to <em class="parameter"><code>address</code></em>.  This must be a valid
      address on one of the host's network interfaces or "0.0.0.0" or
      "::".  An optional port may be specified by appending
      "#&lt;port&gt;"
    </p>

    <p>
      The <code class="option">-m</code> option enables memory usage debugging.
    </p>

    <p>
      The <code class="option">-p</code> option is used when a non-standard port
      number is to be queried.
      <em class="parameter"><code>port#</code></em> is the port number
      that <span class="command"><strong>mdig</strong></span> will send its queries instead of
      the standard DNS port number 53.  This option would be used to
      test a name server that has been configured to listen for
      queries on a non-standard port number.
    </p>

    <p>
      The global query options are:
      </p>
<div class="variablelist"><dl class="variablelist">
<dt><span class="term"><code class="option">+[no]additional</code></span></dt>
<dd>
            <p>
              Display [do not display] the additional section of a
              reply.  The default is to display it.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]all</code></span></dt>
<dd>
            <p>
              Set or clear all display flags.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]answer</code></span></dt>
<dd>
            <p>
              Display [do not display] the answer section of a
              reply.  The default is to display it.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]authority</code></span></dt>
<dd>
            <p>
              Display [do not display] the authority section of a
              reply.  The default is to display it.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]besteffort</code></span></dt>
<dd>
            <p>
              Attempt to display the contents of messages which are
              malformed.  The default is to not display malformed
              answers.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]cl</code></span></dt>
<dd>
            <p>
              Display [do not display] the CLASS when printing the
              record.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]comments</code></span></dt>
<dd>
            <p>
              Toggle the display of comment lines in the output.
              The default is to print comments.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]continue</code></span></dt>
<dd>
            <p>
              Continue on errors (e.g. timeouts).
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]crypto</code></span></dt>
<dd>
            <p>
              Toggle the display of cryptographic fields in DNSSEC
              records.  The contents of these field are unnecessary
              to debug most DNSSEC validation failures and removing
              them makes it easier to see the common failures.  The
              default is to display the fields.  When omitted they
              are replaced by the string "[omitted]" or in the
              DNSKEY case the key id is displayed as the replacement,
              e.g. "[ key id = value ]".
            </p>
          </dd>
<dt><span class="term"><code class="option">+dscp[=value]</code></span></dt>
<dd>
            <p>
              Set the DSCP code point to be used when sending the
              query.  Valid DSCP code points are in the range
              [0..63].  By default no code point is explicitly set.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]multiline</code></span></dt>
<dd>
            <p>
              Print records like the SOA records in a verbose
              multi-line format with human-readable comments.  The
              default is to print each record on a single line, to
              facilitate machine parsing of the <span class="command"><strong>mdig</strong></span>
              output.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]question</code></span></dt>
<dd>
            <p>
              Print [do not print] the question section of a query
              when an answer is returned.  The default is to print
              the question section as a comment.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]rrcomments</code></span></dt>
<dd>
            <p>
              Toggle the display of per-record comments in the
              output (for example, human-readable key information
              about DNSKEY records).  The default is not to print
              record comments unless multiline mode is active.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]short</code></span></dt>
<dd>
            <p>
              Provide a terse answer.  The default is to print the
              answer in a verbose form.
            </p>
          </dd>
<dt><span class="term"><code class="option">+split=W</code></span></dt>
<dd>
            <p>
              Split long hex- or base64-formatted fields in resource
              records into chunks of <em class="parameter"><code>W</code></em>
              characters (where <em class="parameter"><code>W</code></em> is rounded
              up to the nearest multiple of 4).
              <em class="parameter"><code>+nosplit</code></em> or
              <em class="parameter"><code>+split=0</code></em> causes fields not to
              be split at all.  The default is 56 characters, or
              44 characters when multiline mode is active.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]tcp</code></span></dt>
<dd>
            <p>
              Use [do not use] TCP when querying name servers. The
              default behavior is to use UDP.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]ttlid</code></span></dt>
<dd>
            <p>
              Display [do not display] the TTL when printing the
              record.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]ttlunits</code></span></dt>
<dd>
            <p>
              Display [do not display] the TTL in friendly human-readable
              time units of "s", "m", "h", "d", and "w", representing
              seconds, minutes, hours, days and weeks.  Implies +ttlid.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]vc</code></span></dt>
<dd>
            <p>
              Use [do not use] TCP when querying name servers.  This
              alternate syntax to <em class="parameter"><code>+[no]tcp</code></em>
              is provided for backwards compatibility.  The "vc"
              stands for "virtual circuit".
            </p>
          </dd>
</dl></div>
<p>

    </p>
  </div>

  <div class="refsection">
<a name="id-1.10"></a><h2>LOCAL OPTIONS</h2>


    <p>
      The <code class="option">-c</code> option sets the query class to
      <em class="parameter"><code>class</code></em>.  It can be any valid query class
      which is supported in BIND 9.  The default query class is "IN".
    </p>

    <p>
      The <code class="option">-t</code> option sets the query type to
      <em class="parameter"><code>type</code></em>.  It can be any valid query type
      which is supported in BIND 9.  The default query type is "A",
      unless the <code class="option">-x</code> option is supplied to indicate
      a reverse lookup with the "PTR" query type.
    </p>

    <p>
      Reverse lookups &#8212; mapping addresses to names &#8212; are
      simplified by the <code class="option">-x</code> option.
      <em class="parameter"><code>addr</code></em> is an IPv4
      address in dotted-decimal notation, or a colon-delimited IPv6 address.
      <span class="command"><strong>mdig</strong></span> automatically performs a lookup for a
      query name like <code class="literal">11.12.13.10.in-addr.arpa</code> and
      sets the query type and class to PTR and IN respectively.
      By default, IPv6 addresses are looked up using nibble format
      under the IP6.ARPA domain.
    </p>

    <p>
      The local query options are:
      </p>
<div class="variablelist"><dl class="variablelist">
<dt><span class="term"><code class="option">+[no]aaflag</code></span></dt>
<dd>
            <p>
              A synonym for <em class="parameter"><code>+[no]aaonly</code></em>.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]aaonly</code></span></dt>
<dd>
            <p>
              Sets the "aa" flag in the query.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]adflag</code></span></dt>
<dd>
            <p>
              Set [do not set] the AD (authentic data) bit in the
              query.  This requests the server to return whether
              all of the answer and authority sections have all
              been validated as secure according to the security
              policy of the server.  AD=1 indicates that all records
              have been validated as secure and the answer is not
              from a OPT-OUT range.  AD=0 indicate that some part
              of the answer was insecure or not validated.  This
              bit is set by default.
            </p>
          </dd>
<dt><span class="term"><code class="option">+bufsize=B</code></span></dt>
<dd>
            <p>
              Set the UDP message buffer size advertised using EDNS0
              to <em class="parameter"><code>B</code></em> bytes.  The maximum and
              minimum sizes of this buffer are 65535 and 0 respectively.
              Values outside this range are rounded up or down
              appropriately.  Values other than zero will cause a
              EDNS query to be sent.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]cdflag</code></span></dt>
<dd>
            <p>
              Set [do not set] the CD (checking disabled) bit in
              the query.  This requests the server to not perform
              DNSSEC validation of responses.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]cookie[<span class="optional">=####</span>]</code></span></dt>
<dd>
	    <p>
	      Send a COOKIE EDNS option, with optional value.
	      Replaying a COOKIE from a previous response will allow
	      the server to identify a previous client.  The default
	      is <code class="option">+nocookie</code>.
	    </p>
	  </dd>
<dt><span class="term"><code class="option">+[no]dnssec</code></span></dt>
<dd>
            <p>
              Requests DNSSEC records be sent by setting the DNSSEC
              OK bit (DO) in the OPT record in the additional section
              of the query.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]edns[=#]</code></span></dt>
<dd>
            <p>
               Specify the EDNS version to query with.  Valid values
               are 0 to 255.  Setting the EDNS version will cause
               a EDNS query to be sent.  <code class="option">+noedns</code>
               clears the remembered EDNS version.  EDNS is set to
               0 by default.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]ednsflags[=#]</code></span></dt>
<dd>
            <p>
              Set the must-be-zero EDNS flags bits (Z bits) to the
              specified value. Decimal, hex and octal encodings are
              accepted. Setting a named flag (e.g. DO) will silently be
              ignored. By default, no Z bits are set.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]ednsopt[=code[:value]]</code></span></dt>
<dd>
            <p>
              Specify EDNS option with code point <code class="option">code</code>
              and optionally payload of <code class="option">value</code> as a
              hexadecimal string.  <code class="option">+noednsopt</code>
              clears the EDNS options to be sent.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]expire</code></span></dt>
<dd>
            <p>
              Send an EDNS Expire option.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]nsid</code></span></dt>
<dd>
            <p>
              Include an EDNS name server ID request when sending
              a query.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]recurse</code></span></dt>
<dd>
            <p>
              Toggle the setting of the RD (recursion desired) bit
              in the query.  This bit is set by default, which means
              <span class="command"><strong>mdig</strong></span> normally sends recursive
              queries.
            </p>
          </dd>
<dt><span class="term"><code class="option">+retry=T</code></span></dt>
<dd>
            <p>
              Sets the number of times to retry UDP queries to
              server to <em class="parameter"><code>T</code></em> instead of the
              default, 2.  Unlike <em class="parameter"><code>+tries</code></em>,
              this does not include the initial query.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]subnet=addr[/prefix-length]</code></span></dt>
<dd>
	    <p>
	      Send (don't send) an EDNS Client Subnet option with the
              specified IP address or network prefix.
	    </p>
	    <p>
              <span class="command"><strong>mdig +subnet=0.0.0.0/0</strong></span>, or simply
              <span class="command"><strong>mdig +subnet=0</strong></span> for short, sends an EDNS
              client-subnet option with an empty address and a source
              prefix-length of zero, which signals a resolver that
              the client's address information must
              <span class="emphasis"><em>not</em></span> be used when resolving
              this query.
	    </p>
          </dd>
<dt><span class="term"><code class="option">+timeout=T</code></span></dt>
<dd>
            <p>
              Sets the timeout for a query to
              <em class="parameter"><code>T</code></em> seconds.  The default
              timeout is 5 seconds for UDP transport and 10 for TCP.
              An attempt to set <em class="parameter"><code>T</code></em> to less
              than 1 will result
              in a query timeout of 1 second being applied.
            </p>
          </dd>
<dt><span class="term"><code class="option">+tries=T</code></span></dt>
<dd>
            <p>
              Sets the number of times to try UDP queries to server
              to <em class="parameter"><code>T</code></em> instead of the default,
              3.  If <em class="parameter"><code>T</code></em> is less than or equal
              to zero, the number of tries is silently rounded up
              to 1.
            </p>
          </dd>
<dt><span class="term"><code class="option">+udptimeout=T</code></span></dt>
<dd>
            <p>
              Sets the timeout between UDP query retries.
            </p>
          </dd>
<dt><span class="term"><code class="option">+[no]unknownformat</code></span></dt>
<dd>
	    <p>
	      Print all RDATA in unknown RR type presentation format
	      (RFC 3597). The default is to print RDATA for known types
	      in the type's presentation format.
	    </p>
	  </dd>
<dt><span class="term"><code class="option">+[no]zflag</code></span></dt>
<dd>
            <p>
              Set [do not set] the last unassigned DNS header flag in a
              DNS query.  This flag is off by default.
            </p>
          </dd>
</dl></div>
<p>

    </p>
  </div>

  <div class="refsection">
<a name="id-1.11"></a><h2>SEE ALSO</h2>

    <p><span class="citerefentry">
        <span class="refentrytitle">dig</span>(1)
      </span>,
      <em class="citetitle">RFC1035</em>.
    </p>
  </div>
</div></body>
</html>