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 per-
centage 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 simply 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
interface (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 informa-
tion.
-g, --gtk
Use this option to force mtr to use the GTK+ based X11 window
interface (if available). GTK+ must have been available on the
system when mtr was built for this to work. See the GTK+ web
page at ⟨http://www.gtk.org/⟩ 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 be-
tween 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
machines. 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 inter-
face.
-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 ig-
nored, 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
combined with a short interval, will use up a lot of file de-
scriptors.
-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 ⟨http://www.bitwizard.
nl/mtr/⟩
For patches, bug reports, or feature requests, please open an issue on
GitHub at: ⟨https://github.com/traviscross/mtr⟩.
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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