mtr Man page

MTR(8) mtr MTR(8)

NAME

mtr – a network diagnostic tool

SYNOPSIS

mtr [-4|-6] [-F FILENAME] [–report] [–report-wide] [–xml] [–gtk] [–curses] [–raw] [–csv] [–split] [–no-dns] [–show-ips] [-o FIELDS] [-y IPINFO] [–aslookup] [-i INTERVAL] [-c COUNT] [-s PACK‐
ETSIZE] [-B BITPATTERN] [-Q TOS] [–mpls] [-a ADDRESS] [-f FIRST-TTL] [-m MAX-TTL] [–udp] [–tcp] [-P PORT] [-Z TIMEOUT] [-M MARK] HOST

NAME

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
miliseconds and the percentage of packetloss.

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 FILE

NAME

MISSING

-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 perfor‐
mance.

-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).

-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 this option to tell mtr to 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.

-C, –csv
MISSING

-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
MISSING

-z, –aslookup
MISSING

-i SECONDS, –interval SECONDS
Use this option to specify the positive number of seconds
between ICMP ECHO requests. The default value for this parame‐
ter 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.

-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
extensions for MPLS (RFC 4950) that are encoded in the response
packets.

-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, –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.

-P PORT, –port PORT
The target port number for TCP traces.

-Z SECONDS, –timeout SECONDS
The number of seconds to keep the TCP socket open before giving
up on the connection. This will only affect the final hop.
Using large values for this, especially combined with a short
interval, will use up a lot of file descriptors.

-M MARK, –mark MARK
MISSING

ENVIRONMENT
mtr recognizes a few environment variables.

MTR_

OPTIONS

This environment variable allows to specify options, as if they
were passed on the command line. It is parsed before reading
the actual command line options, so that options specified in
MTR_OPTIONS are overriden 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).

DISPLAY
Used for the GTK+ frontend.

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.bitwiz‐
ard.nl/mtr/.

The mtr mailinglist was little used and is no longer active.

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

SEE ALSO

traceroute(8), ping(8) TCP/IP Illustrated (Stevens, ISBN 0201633469).

mtr July 12, 2014 MTR(8)