1MTR(8)                       System Administration                      MTR(8)
2
3
4

NAME

6       mtr - a network diagnostic tool
7

SYNOPSIS

9       mtr  [-4|-6]  [-F FILENAME]  [--report] [--report-wide] [--xml] [--gtk]
10       [--curses]  [--displaymode MODE]  [--raw]  [--csv]  [--json]  [--split]
11       [--no-dns] [--show-ips] [-o FIELDS] [-y IPINFO] [--aslookup] [-i INTER‐
12       VAL]  [-c COUNT]   [-s PACKETSIZE]   [-B BITPATTERN]   [-G GRACEPERIOD]
13       [-Q TOS]  [--mpls]  [-I NAME]  [-a ADDRESS] [-f FIRST-TTL] [-m MAX-TTL]
14       [-U MAX-UNKNOWN]  [--udp]  [--tcp]  [--sctp]  [-P PORT]  [-L LOCALPORT]
15       [-Z TIMEOUT] [-M MARK] HOSTNAME
16

DESCRIPTION

18       mtr combines the functionality of the traceroute and ping programs in a
19       single network diagnostic tool.
20
21       As mtr starts, it investigates the network connection between the  host
22       mtr  runs  on  and HOSTNAME by sending packets with purposely low TTLs.
23       It continues to send packets with low TTL, noting the response time  of
24       the  intervening  routers.   This allows mtr to print the response per‐
25       centage and response times of the internet route to HOSTNAME.  A sudden
26       increase  in  packet  loss or response time is often an indication of a
27       bad (or simply overloaded) link.
28
29       The results are usually reported as round-trip-response times  in  mil‐
30       liseconds and the percentage of packet loss.
31

OPTIONS

33       -h, --help
34              Print the summary of command line argument options.
35
36       -v, --version
37              Print the installed version of mtr.
38
39       -4     Use IPv4 only.
40
41       -6     Use IPv6 only.  (IPV4 may be used for DNS lookups.)
42
43       -F FILENAME, --filename FILENAME
44              Reads the list of hostnames from the specified file.
45
46       -r, --report
47              This  option  puts mtr into report mode.  When in this mode, mtr
48              will run for the number of cycles specified by  the  -c  option,
49              and then print statistics and exit.
50
51       This mode is useful for generating statistics about network quality.
52              Note  that  each running instance of mtr generates a significant
53              amount of network traffic.  Using mtr to measure the quality  of
54              your network may result in decreased network performance.
55
56       -w, --report-wide
57              This  option puts mtr into wide report mode.  When in this mode,
58              mtr will not cut hostnames in the report.
59
60       -x, --xml
61              Use this option to tell mtr to use the xml output format.   This
62              format is better suited for automated processing of the measure‐
63              ment results.
64
65       -t, --curses
66              Use this option to force mtr to use the  curses  based  terminal
67              interface  (if available).  In case the list of hops exceeds the
68              height of your terminal, you can use the + and - keys to  scroll
69              up and down half a page.
70
71              Ctrl-L  clears  spurious error messages that may overwrite other
72              parts of the display.
73
74
75       --displaymode MODE
76              Use this option to select the initial display mode: 0  (default)
77              selects statistics, 1 selects the stripchart without latency in‐
78              formation, and 2 selects the stripchart  with  latency  informa‐
79              tion.
80
81       -g, --gtk
82              Use  this  option  to force mtr to use the GTK+ based X11 window
83              interface (if available).  GTK+ must have been available on  the
84              system  when  mtr  was built for this to work.  See the GTK+ web
85              page at ⟨http://www.gtk.org/⟩ for more information about GTK+.
86
87       -l, --raw
88              Use the raw output format.  This format  is  better  suited  for
89              archival  of  the measurement results.  It could be parsed to be
90              presented into any of the other display methods.
91
92              Example of the raw output format:
93              h 0 10.1.1.1
94              p 0 339
95              h 1 46.149.16.4
96              p 1 530
97              h 2 172.31.1.16
98              p 2 531
99              h 3 82.221.168.236
100              p 3 1523
101              h 5 195.130.211.8
102              p 5 1603
103              h 6 193.4.58.17
104              p 6 1127
105              h 7 193.4.58.17
106              d 7 www.isnic.is
107
108       -C, --csv
109              Use the Comma-Separated-Value (CSV) output format.   (Note:  The
110              separator is actually a semi-colon ';'.)
111
112              Example of the CSV output format:
113              MTR.0.86+git:16e39fc0;1435562787;OK;nic.is;1;r-76520-PROD.greenqloud.internal;288
114              MTR.0.86+git:16e39fc0;1435562787;OK;nic.is;2;46.149.16.4;2086
115              MTR.0.86+git:16e39fc0;1435562787;OK;nic.is;3;172.31.1.16;600
116              MTR.0.86+git:16e39fc0;1435562787;OK;nic.is;4;82.221.168.236;1163
117              MTR.0.86+git:16e39fc0;1435562787;OK;nic.is;5;???;0
118              MTR.0.86+git:16e39fc0;1435562787;OK;nic.is;6;rix-k2-gw.isnic.is;1654
119              MTR.0.86+git:16e39fc0;1435562787;OK;nic.is;7;www.isnic.is;1036
120
121       -j, --json
122              Use this option to tell mtr to use the JSON output format.  This
123              format is better suited for automated processing of the measure‐
124              ment  results.   Jansson library must have been available on the
125              system when mtr was built for this to work.
126
127       -p, --split
128              Use this option to set mtr to spit out a format that is suitable
129              for a split-user interface.
130
131       -n, --no-dns
132              Use  this  option to force mtr to display numeric IP numbers and
133              not try to resolve the host names.
134
135       -b, --show-ips
136              Use this option to tell mtr to display both the host  names  and
137              numeric  IP  numbers.  In split mode this adds an extra field to
138              the output.  In report mode, there is usually too  little  space
139              to add the IPs, and they will be truncated.  Use the wide report
140              (-w) mode to see the IPs in report mode.
141
142       -o FIELDS, --order FIELDS
143              Use this option to specify which fields to display and in  which
144              order.   You  may  use  one or more space characters to separate
145              fields.
146              Available fields:
147
148                                 ┌──┬─────────────────────┐
149                                 │L │ Loss ratio          │
150                                 ├──┼─────────────────────┤
151                                 │D │ Dropped packets     │
152                                 ├──┼─────────────────────┤
153                                 │R │ Received packets    │
154                                 ├──┼─────────────────────┤
155                                 │S │ Sent Packets        │
156                                 ├──┼─────────────────────┤
157                                 │N │ Newest RTT(ms)      │
158                                 ├──┼─────────────────────┤
159                                 │B │ Min/Best RTT(ms)    │
160                                 ├──┼─────────────────────┤
161                                 │A │ Average RTT(ms)     │
162                                 ├──┼─────────────────────┤
163                                 │W │ Max/Worst RTT(ms)   │
164                                 ├──┼─────────────────────┤
165                                 │V │ Standard Deviation  │
166                                 ├──┼─────────────────────┤
167                                 │G │ Geometric Mean      │
168                                 ├──┼─────────────────────┤
169                                 │J │ Current Jitter      │
170                                 ├──┼─────────────────────┤
171                                 │M │ Jitter Mean/Avg.    │
172                                 ├──┼─────────────────────┤
173                                 │X │ Worst Jitter        │
174                                 ├──┼─────────────────────┤
175                                 │I │ Interarrival Jitter │
176                                 └──┴─────────────────────┘
177              Example: -o "LSD NBAW  X"
178
179       -y n, --ipinfo n
180              Displays information about each IP hop.  Valid values for n are:
181
182              0   Display AS number (equivalent to -z)
183              1   Display IP prefix
184              2   Display country code of the origin AS
185              3   Display RIR (ripencc, arin, ...)
186              4   Display the allocation date of the IP prefix
187
188              It is possible to cycle between these fields at  runtime  (using
189              the y key).
190
191       -z, --aslookup
192              Displays  the  Autonomous System (AS) number alongside each hop.
193              Equivalent to --ipinfo 0.
194
195              Example (columns to the right not shown for clarity):
196              1. AS???   r-76520-PROD.greenqloud.internal
197              2. AS51969 46.149.16.4
198              3. AS???   172.31.1.16
199              4. AS30818 82.221.168.236
200              5. ???
201              6. AS???   rix-k2-gw.isnic.is
202              7. AS1850  www.isnic.is
203
204       -i SECONDS, --interval SECONDS
205              Use this option to specify the positive number  of  seconds  be‐
206              tween  ICMP ECHO requests.  The default value for this parameter
207              is one second.  The root user may choose values between zero and
208              one.
209
210       -c COUNT, --report-cycles COUNT
211              Use  this  option  to  set the number of pings sent to determine
212              both the machines on the network and the  reliability  of  those
213              machines.  Each cycle lasts one second.
214
215       -s PACKETSIZE, --psize PACKETSIZE
216              This  option  sets  the  packet size used for probing.  It is in
217              bytes, inclusive IP and ICMP headers.
218
219              If set to a negative number, every iteration will use a  differ‐
220              ent, random packet size up to that number.
221
222       -B NUM, --bitpattern NUM
223              Specifies bit pattern to use in payload.  Should be within range
224              0 - 255.  If NUM is greater than 255, a random pattern is used.
225
226       -G SECONDS, --gracetime SECONDS
227              Use this option to specify the positive  number  of  seconds  to
228              wait for responses after the final request. The default value is
229              five seconds.
230
231       -Q NUM, --tos NUM
232              Specifies value for type of service field in IP header.   Should
233              be within range 0 - 255.
234
235       -e, --mpls
236              Use this option to tell mtr to display information from ICMP ex‐
237              tensions for MPLS (RFC 4950) that are encoded  in  the  response
238              packets.
239
240       -I NAME, --interface NAME
241              Use  the network interface with a specific name for sending net‐
242              work probes.  This can be useful when you have multiple  network
243              interfaces  with  routes  to  your destination, for example both
244              wired Ethernet and WiFi, and wish to test  a  particular  inter‐
245              face.
246
247       -a ADDRESS, --address ADDRESS
248              Use  this option to bind the outgoing socket to ADDRESS, so that
249              all packets will be sent with ADDRESS as source  address.   NOTE
250              that  this  option doesn't apply to DNS requests (which could be
251              and could not be what you want).
252
253       -f NUM, --first-ttl NUM
254              Specifies with what TTL to start.  Defaults to 1.
255
256       -m NUM, --max-ttl NUM
257              Specifies the maximum number of hops  (max  time-to-live  value)
258              traceroute will probe.  Default is 30.
259
260       -U NUM, --max-unknown NUM
261              Specifies the maximum unknown host. Default is 5.
262
263       -u, --udp
264              Use UDP datagrams instead of ICMP ECHO.
265
266       -T, --tcp
267              Use  TCP  SYN  packets  instead of ICMP ECHO.  PACKETSIZE is ig‐
268              nored, since SYN packets can not contain data.
269
270       -S, --sctp
271              Use Stream Control Transmission Protocol packets instead of ICMP
272              ECHO.
273
274       -P PORT, --port PORT
275              The target port number for TCP/SCTP/UDP traces.
276
277       -L LOCALPORT, --localport LOCALPORT
278              The source port number for UDP traces.
279
280       -Z SECONDS, --timeout SECONDS
281              The  number  of seconds to keep probe sockets open before giving
282              up on the connection.  Using large values for  this,  especially
283              combined  with  a  short interval, will use up a lot of file de‐
284              scriptors.
285
286       -M MARK, --mark MARK
287              Set the mark for each packet sent through this socket similar to
288              the netfilter MARK target but socket-based.  MARK is 32 unsigned
289              integer.  See socket(7) for full description of this socket  op‐
290              tion.
291

ENVIRONMENT

293       mtr recognizes a few environment variables.
294
295       MTR_OPTIONS
296              This  environment  variable allows one to specify options, as if
297              they were passed on the command line.  It is parsed before read‐
298              ing  the  actual command line options, so that options specified
299              in MTR_OPTIONS are overridden by command-line options.
300
301              Example:
302
303              MTR_OPTIONS="-4 -c 1" mtr -6 localhost
304
305              would send one probe (because of -c 1) towards ::1  (because  of
306              -6, which overrides the -4 passed in MTR_OPTIONS).
307
308       MTR_PACKET
309              A  path to the mtr-packet executable, to be used for sending and
310              receiving network probes.  If MTR_PACKET is unset, the PATH will
311              be used to search for an mtr-packet executable.
312
313       DISPLAY
314              Specifies an X11 server for the GTK+ frontend.
315

INTERACTIVE CONTROL

317       mtr can be controlled while it is running with the following keys:
318         ?|h     help
319         p       pause (SPACE to resume)
320         d       switching display mode
321         e       toggle MPLS information on/off
322         n       toggle DNS on/off
323         r       reset all counters
324         o str   set the columns to display, default str='LRS N BAWV'
325         j       toggle latency(LS NABWV)/jitter(DR AGJMXI) stats
326         c <n>   report cycle n, default n=infinite
327         i <n>   set the ping interval to n seconds, default n=1
328         f <n>   set the initial time-to-live(ttl), default n=1
329         m <n>   set the max time-to-live, default n= # of hops
330         s <n>   set the packet size to n or random(n<0)
331         b <c>   set ping bit pattern to c(0..255) or random(c<0)
332         Q <t>   set ping packet's TOS to t
333         u       switch between ICMP ECHO and UDP datagrams
334         y       switching IP info
335         z       toggle ASN info on/off
336         q       exit
337

BUGS

339       Some  modern routers give a lower priority to ICMP ECHO packets than to
340       other network traffic.  Consequently, the reliability of these  routers
341       reported by mtr will be significantly lower than the actual reliability
342       of these routers.
343

CONTACT INFORMATION

345       For the latest version, see the mtr web page at  ⟨http://www.bitwizard.
346       nl/mtr/⟩
347
348       For  patches, bug reports, or feature requests, please open an issue on
349       GitHub at: ⟨https://github.com/traviscross/mtr⟩.
350

SEE ALSO

352       mtr-packet(8), traceroute(8), ping(8),  socket(7),  TCP/IP  Illustrated
353       (Stevens, ISBN 0201633469).
354
355
356
357mtr                                  0.95                               MTR(8)
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