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MTR(8)                       System Administration                       MTR(8)

NAME
       mtr - a network diagnostic tool

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

DESCRIPTION
       mtr  combines the functionality of the traceroute and ping programs in a
       single network diagnostic tool.

       As mtr starts, it investigates the network connection between  the  host
       mtr runs on and HOSTNAME by sending packets with purposely low TTLs.  It
       continues  to send packets with low TTL, noting the response time of the
       intervening routers.  This allows mtr to print the  response  percentage
       and response times of the internet route to HOSTNAME.  A sudden increase
       in packet loss or response time is often an indication of a bad (or sim-
       ply overloaded) link.

       The  results  are  usually reported as round-trip-response times in mil-
       liseconds and the percentage of packet loss.

OPTIONS
       -h, --help
              Print the summary of command line argument options.

       -v, --version
              Print the installed version of mtr.

       -4     Use IPv4 only.

       -6     Use IPv6 only.  (IPV4 may be used for DNS lookups.)

       -F FILENAME, --filename FILENAME
              Reads the list of hostnames from the specified file.

       -r, --report
              This option puts mtr into report mode.  When in  this  mode,  mtr
              will run for the number of cycles specified by the -c option, and
              then print statistics and exit.

       This mode is useful for generating statistics about network quality.
              Note  that  each  running instance of mtr generates a significant
              amount of network traffic.  Using mtr to measure the  quality  of
              your network may result in decreased network performance.

       -w, --report-wide
              This  option  puts mtr into wide report mode.  When in this mode,
              mtr will not cut hostnames in the report.

       -x, --xml
              Use this option to tell mtr to use the xml output  format.   This
              format  is better suited for automated processing of the measure-
              ment results.

       -t, --curses
              Use this option to force mtr to use the curses based terminal in-
              terface (if available).  In case the list  of  hops  exceeds  the
              height  of  your terminal, you can use the + and - keys to scroll
              up and down half a page.

              Ctrl-L clears spurious error messages that  may  overwrite  other
              parts of the display.

       --displaymode MODE
              Use  this  option to select the initial display mode: 0 (default)
              selects statistics, 1 selects the stripchart without latency  in-
              formation, and 2 selects the stripchart with latency information.

       -g, --gtk
              Use this option to force mtr to use the GTK+ based X11 window in-
              terface  (if  available).   GTK+  must have been available on the
              system when mtr was built for this to work.   See  the  GTK+  web
              page at ]8;;http://www.gtk.org/\http://www.gtk.org/]8;;\ for more information about GTK+.

       -l, --raw
              Use  the  raw  output  format.   This format is better suited for
              archival of the measurement results.  It could be  parsed  to  be
              presented into any of the other display methods.

              Example of the raw output format:
              h 0 10.1.1.1
              p 0 339
              h 1 46.149.16.4
              p 1 530
              h 2 172.31.1.16
              p 2 531
              h 3 82.221.168.236
              p 3 1523
              h 5 195.130.211.8
              p 5 1603
              h 6 193.4.58.17
              p 6 1127
              h 7 193.4.58.17
              d 7 www.isnic.is

       -C, --csv
              Use  the  Comma-Separated-Value  (CSV) output format.  (Note: The
              separator is actually a semi-colon ';'.)

              Example of the CSV output format:
              MTR.0.86+git:16e39fc0;1435562787;OK;nic.is;1;r-76520-PROD.greenqloud.internal;288
              MTR.0.86+git:16e39fc0;1435562787;OK;nic.is;2;46.149.16.4;2086
              MTR.0.86+git:16e39fc0;1435562787;OK;nic.is;3;172.31.1.16;600
              MTR.0.86+git:16e39fc0;1435562787;OK;nic.is;4;82.221.168.236;1163
              MTR.0.86+git:16e39fc0;1435562787;OK;nic.is;5;???;0
              MTR.0.86+git:16e39fc0;1435562787;OK;nic.is;6;rix-k2-gw.isnic.is;1654
              MTR.0.86+git:16e39fc0;1435562787;OK;nic.is;7;www.isnic.is;1036

       -j, --json
              Use this option to tell mtr to use the JSON output format.   This
              format  is better suited for automated processing of the measure-
              ment results.  Jansson library must have been  available  on  the
              system when mtr was built for this to work.

       -p, --split
              Use  this option to set mtr to spit out a format that is suitable
              for a split-user interface.

       -n, --no-dns
              Use this option to force mtr to display numeric  IP  numbers  and
              not try to resolve the host names.

       -b, --show-ips
              Use  this  option  to tell mtr to display both the host names and
              numeric IP numbers.  In split mode this adds an  extra  field  to
              the output.  In report mode, there is usually too little space to
              add  the  IPs,  and  they will be truncated.  Use the wide report
              (-w) mode to see the IPs in report mode.

       -o FIELDS, --order FIELDS
              Use this option to specify which fields to display and  in  which
              order.   You  may  use  one  or more space characters to separate
              fields.
              Available fields:
                                ┌───┬─────────────────────┐
                                │ L │ Loss ratio          │
                                ├───┼─────────────────────┤
                                │ D │ Dropped packets     │
                                ├───┼─────────────────────┤
                                │ R │ Received packets    │
                                ├───┼─────────────────────┤
                                │ S │ Sent Packets        │
                                ├───┼─────────────────────┤
                                │ N │ Newest RTT(ms)      │
                                ├───┼─────────────────────┤
                                │ B │ Min/Best RTT(ms)    │
                                ├───┼─────────────────────┤
                                │ A │ Average RTT(ms)     │
                                ├───┼─────────────────────┤
                                │ W │ Max/Worst RTT(ms)   │
                                ├───┼─────────────────────┤
                                │ V │ Standard Deviation  │
                                ├───┼─────────────────────┤
                                │ G │ Geometric Mean      │
                                ├───┼─────────────────────┤
                                │ J │ Current Jitter      │
                                ├───┼─────────────────────┤
                                │ M │ Jitter Mean/Avg.    │
                                ├───┼─────────────────────┤
                                │ X │ Worst Jitter        │
                                ├───┼─────────────────────┤
                                │ I │ Interarrival Jitter │
                                └───┴─────────────────────┘

              Example: -o "LSD NBAW  X"

       -y n, --ipinfo n
              Displays information about each IP hop.  Valid values for n are:
              0   Display AS number (equivalent to -z)
              1   Display IP prefix
              2   Display country code of the origin AS
              3   Display RIR (ripencc, arin, ...)
              4   Display the allocation date of the IP prefix

              It is possible to cycle between these fields  at  runtime  (using
              the y key).

       -z, --aslookup
              Displays  the  Autonomous  System (AS) number alongside each hop.
              Equivalent to --ipinfo 0.

              Example (columns to the right not shown for clarity):
              1. AS???   r-76520-PROD.greenqloud.internal
              2. AS51969 46.149.16.4
              3. AS???   172.31.1.16
              4. AS30818 82.221.168.236
              5. ???
              6. AS???   rix-k2-gw.isnic.is
              7. AS1850  www.isnic.is

       -i SECONDS, --interval SECONDS
              Use this option to specify the positive number of seconds between
              ICMP ECHO requests.  The default value for this parameter is  one
              second.  The root user may choose values between zero and one.

       -c COUNT, --report-cycles COUNT
              Use this option to set the number of pings sent to determine both
              the  machines  on  the  network  and the reliability of those ma-
              chines.  Each cycle lasts one second.

       -s PACKETSIZE, --psize PACKETSIZE
              This option sets the packet size used  for  probing.   It  is  in
              bytes, inclusive IP and ICMP headers.

              If  set  to a negative number, every iteration will use a differ-
              ent, random packet size up to that number.

       -B NUM, --bitpattern NUM
              Specifies bit pattern to use in payload.  Should be within  range
              0 - 255.  If NUM is greater than 255, a random pattern is used.

       -G SECONDS, --gracetime SECONDS
              Use this option to specify the positive number of seconds to wait
              for  responses after the final request. The default value is five
              seconds.

       -Q NUM, --tos NUM
              Specifies value for type of service field in IP  header.   Should
              be within range 0 - 255.

       -e, --mpls
              Use  this option to tell mtr to display information from ICMP ex-
              tensions for MPLS (RFC 4950) that are  encoded  in  the  response
              packets.

       -I NAME, --interface NAME
              Use  the  network interface with a specific name for sending net-
              work probes.  This can be useful when you have  multiple  network
              interfaces  with  routes  to  your  destination, for example both
              wired Ethernet and WiFi, and wish to test a particular interface.

       -a ADDRESS, --address ADDRESS
              Use this option to bind the outgoing socket to ADDRESS,  so  that
              all  packets  will  be sent with ADDRESS as source address.  NOTE
              that this option doesn't apply to DNS requests  (which  could  be
              and could not be what you want).

       -f NUM, --first-ttl NUM
              Specifies with what TTL to start.  Defaults to 1.

       -m NUM, --max-ttl NUM
              Specifies  the  maximum  number  of hops (max time-to-live value)
              traceroute will probe.  Default is 30.

       -U NUM, --max-unknown NUM
              Specifies the maximum unknown host. Default is 5.

       -u, --udp
              Use UDP datagrams instead of ICMP ECHO.

       -T, --tcp
              Use TCP SYN packets instead of ICMP ECHO.  PACKETSIZE is ignored,
              since SYN packets can not contain data.

       -S, --sctp
              Use Stream Control Transmission Protocol packets instead of  ICMP
              ECHO.

       -P PORT, --port PORT
              The target port number for TCP/SCTP/UDP traces.

       -L LOCALPORT, --localport LOCALPORT
              The source port number for UDP traces.

       -Z SECONDS, --timeout SECONDS
              The number of seconds to keep probe sockets open before giving up
              on  the connection.  Using large values for this, especially com-
              bined with a short interval, will use up a lot of  file  descrip-
              tors.

       -M MARK, --mark MARK
              Set  the mark for each packet sent through this socket similar to
              the netfilter MARK target but socket-based.  MARK is 32  unsigned
              integer.   See  socket(7) for full description of this socket op-
              tion.

ENVIRONMENT
       mtr recognizes a few environment variables.

       MTR_OPTIONS
              This environment variable allows one to specify  options,  as  if
              they  were passed on the command line.  It is parsed before read-
              ing the actual command line options, so that options specified in
              MTR_OPTIONS are overridden by command-line options.

              Example:

              MTR_OPTIONS="-4 -c 1" mtr -6 localhost

              would send one probe (because of -c 1) towards  ::1  (because  of
              -6, which overrides the -4 passed in MTR_OPTIONS).

       MTR_PACKET
              A  path  to the mtr-packet executable, to be used for sending and
              receiving network probes.  If MTR_PACKET is unset, the PATH  will
              be used to search for an mtr-packet executable.

       DISPLAY
              Specifies an X11 server for the GTK+ frontend.

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

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

CONTACT INFORMATION
       For the latest version, see the mtr web page at ]8;;http://www.bitwizard.nl/mtr/\http://www.bitwizard.nl/
       mtr/]8;;\

       For patches, bug reports, or feature requests, please open an  issue  on
       GitHub at: ]8;;https://github.com/traviscross/mtr\https://github.com/traviscross/mtr]8;;\.

SEE ALSO
       mtr-packet(8),  traceroute(8),  ping(8),  socket(7),  TCP/IP Illustrated
       (Stevens, ISBN 0201633469).

mtr                                   0.95                               MTR(8)

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