| Developer(s) | BitWizard |
|---|---|
| Initial release | 1997 |
| Stable release | 0.82 / December 2, 2011 |
| Written in | C |
| Operating system | Unix-like |
| Type | Network |
| License | GNU General Public License Version 2 |
| Website | www.bitwizard.nl/mtr/ |
| Developer(s) | Appnor |
|---|---|
| Stable release | 0.92 / January 31, 2011 |
| Written in | C |
| Operating system | Windows |
| Type | Network |
| License | GNU General Public License Version 2 |
| Website | www.winmtr.net |
MTR is computer software which combines the functionality of the traceroute and ping programs in a single network diagnostic tool.[1]
MTR probes routers on the route path by limiting the number of hops individual packets may traverse, and listening to responses of their expiry. It will regularly repeat this process, usually once per second, and keep track of the response times of the hops along the path.
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The original MTR (known as Matt's traceroute) program was written by Matt Kimball in 1997. Roger Wolff took over maintenance of MTR (renamed to My traceroute) in October 1998.[2]
MTR is licensed under the terms of the GNU General Public License (GPL) and it works under modern Unix-like operating systems. It normally works under the text console, but it also has an optional GTK+-based graphical interface.
MTR relies on ICMP Time Exceeded (type 11, code 0) packets coming back from routers, or ICMP Echo Reply packets when the packets have hit their destination host. MTR also has a UDP mode (invoked with "-u" on the command line or pressing the "u" key in the curses interface) that sends UDP packets, each with an increasing destination port, toward the destination host. When the UDP mode is used, MTR relies on ICMP port unreachable packets (type 3, code 3) when the destination is reached.
MTR also supports IPv6 and works in a similar manner but instead relies on ICMPv6 messages.
The tool is often used for network troubleshooting. By showing a list of routers traversed, and the average round-trip time as well as packet loss to each router, it allows the user to identify links between two particular routers responsible for certain fractions of the overall latency or packet loss through the network. This can help identify network over utilization problems.[3]
This example shows MTR running on Linux tracing a route from the host machine (example.lan) to a web server at Yahoo! (p25.www.re2.yahoo.com) across the Level3 network.
My traceroute [v0.71]
example.lan Sun Mar 25 00:07:50 2007
Packets Pings
Hostname %Loss Rcv Snt Last Best Avg Worst
1. example.lan 0% 11 11 1 1 1 2
2. ae-31-51.ebr1.Chicago1.Level3.n 19% 9 11 3 1 7 14
3. ae-1.ebr2.Chicago1.Level3.net 0% 11 11 7 1 7 14
4. ae-2.ebr2.Washington1.Level3.ne 19% 9 11 19 18 23 31
5. ae-1.ebr1.Washington1.Level3.ne 28% 8 11 22 18 24 30
6. ge-3-0-0-53.gar1.Washington1.Le 0% 11 11 18 18 20 36
7. 63.210.29.230 0% 10 10 19 19 19 19
8. t-3-1.bas1.re2.yahoo.com 0% 10 10 19 18 32 106
9. p25.www.re2.yahoo.com 0% 10 10 19 18 19 19
An additional example below shows a recent version of MTR running on FreeBSD. MPLS labels are displayed by default when the "-e" switch is used on the command line (or the "u" key is pressed in the curses interface):
My traceroute [v0.82]
dax.prolixium.com (0.0.0.0) Sun Jan 1 12:58:02 2012
Keys: Help Display mode Restart statistics Order of fields quit
Packets Pings
Host Loss% Snt Last Avg Best Wrst StDev
1. voxel.prolixium.net 0.0% 13 0.4 1.7 0.4 10.4 3.2
2. 0.ae2.tsr1.lga5.us.voxel.net 0.0% 12 10.8 2.9 0.2 10.8 4.3
3. 0.ae59.tsr1.lga3.us.voxel.net 0.0% 12 0.4 1.7 0.4 16.0 4.5
4. rtr.loss.net.internet2.edu 0.0% 12 4.8 7.4 0.3 41.8 15.4
5. 64.57.21.210 0.0% 12 5.4 15.7 5.3 126.7 35.0
6. nox1sumgw1-vl-530-nox-mit.nox.org 0.0% 12 109.5 60.6 23.0 219.5 66.0
[MPLS: Lbl 172832 Exp 0 S 1 TTL 1]
7. nox1sumgw1-peer--207-210-142-234.nox.org 0.0% 12 25.0 23.2 23.0 25.0 0.6
8. B24-RTR-2-BACKBONE-2.MIT.EDU 0.0% 12 23.2 23.4 23.2 24.9 0.5
9. MITNET.TRANTOR.CSAIL.MIT.EDU 0.0% 12 23.4 23.4 23.3 23.5 0.1
10. trantor.helicon.csail.mit.edu 0.0% 12 23.7 25.0 23.5 26.5 1.3
11. zermatt.csail.mit.edu 0.0% 12 23.1 23.1 23.1 23.3 0.1
WinMTR is an equivalent of mtr for Windows developed by Appnor. Functionally it is very similar, although it does not actually share any code in common with mtr due to the major diffences between the *nix and Windows network stacks.