MTR is a simple network diagnostics tool that combines the functionality of traceroute and ping programs commonly used as a single tool. The traceroute program was initially designed as a Unix application that allows you to view the path that the information circulates in the Internet by tracking a data packet sent from your local computer to any computer or any server recipient on the Internet.
The traceroute application can help, for example, in determining which are the servers that cause delays in forwarding the data, which can stop all communication. It sends special packets of data (called ICMP packets) to the computer to which link verification is attempted. A computer that receives such packages will return them back, so that if a connection exists, the computer will receive them in an echo. Traceroute tests the connection piece by piece, recording the time needed to transmit the packages up to each “hop” of the route. “Hop” is generally any computer through which the connection passes. If the packages arrive at a computer with two network cards, only the first card will be displayed. If the package can no longer be sent by the second card (the next “hop” can not be called), this last track will also be displayed.
traceroute IP for Linux
tracert IP for Windows
The program displays the received packages and if it does not get back the sent packages it does not show anything.
Under Windows, messages that say “Time out” are displayed – the ping response has been waited for too long.
If the connection works, the network cards / computers through which the connection passes and the time needed to reach each of them will be displayed.
A star symbol indicates a delay in connection, possibly losing packages. There is a worse connection there.
A very long time difference between two consecutive bumps says that the link between the two addresses induces a long delay and an optimization of the connection should be made at that point.
There are some cases where the destination computer does not respond to traceroutes even if the connection is intact:
Routes are wrong – they can be wrong routes on the computer that packages are leaving (usually the “host unreachable” message) or the computer on which packages are received.
The “other” computer has a firewall that filters ping packets. It does not happen very often. You have to check if the person on the other computer can ping to their own board and to a local network card.
If the client can not ping on the local gateway then it surely has a firewall.
MTR
When the MTR test is started, the connectivity between the computer running the MTR and the destination computer specified by the user is checked.
After the IP address of each hop is determined as the destination computer, MTR will send ICMP ECHO REQUEST packets to the address of each hop to determine the quality of the connection.
It then displays detailed statistics.
As an example of usage, to check the quality of an internet connection between two hosts, you can determine the route, RTT in each hop, and packet loss.
In every hop on the route, if any. Interpretation of statistics is contextual.
Note that for reasons of DDoS attack protection, Internet service providers may filter or limit ICMP and UDP packets required for the diagnostic tools listed above.
MTR is available in binary format for most Linux distributions such as Slackware, Red Hat, Fedora, Mandriva, Debian.