The tracert command is used to run a diagnostic utility that determines the route of traffic through the network. This program is present on most modern operating systems. The utility is used mainly when testing and identifying a problem place in the network.
What does the tracert command verify?
Tracert sends requests to the destination like
the ping command. Noticing that the tracert command was issued by the user, Windows sends specially marked packets that, upon reaching the first gateway, are returned back to the user's computer. At the same time, the received data contains information about the node that returned it. After that, the next request is sent, in the body of which there is already an instruction to skip it to the previous gateway.
Sequential packet sending allows you to get the full route of information from the user's computer to any node on the Internet or local network. Thus, the tracert command becomes a necessary tool in diagnosing problems, allowing you to identify the area where packets are lost.
Running tracert command on Windows
You can run the network route check utility on Windows from the command line. In versions of the operating system below 8, to open the command line interface, just click "Start-Run" and type cmd. In Windows 8, you have to go to the "All Programs" menu and find the "Command Prompt" item there. In any version of the OS, you can also use the keyboard shortcut Win + R.
Once in the command line, you must enter tracert domen.ru, where instead of domen.ru you can specify any domain name or IP address. This will launch the utility with standard parameters.
Tracert command keys
Launched by an experienced user, the tracert command contains a description of the keys. It can be called simply by typing the tracert command with the -? Parameter.
Here is a brief description of the options that the tracert command supports:
- -h sets the maximum number of transitions that can be performed when searching for the end node.
- -d prevents the command from attempting to turn the IP address of the intermediate gateway into a name.
- -j allows the utility to freely search for a route through a list of nodes. A maximum of 9 routers can be specified.
- -w is used to specify the time to wait for a response to a request from a node. If no response is received, an asterisk will be displayed. Indicated in milliseconds.
By default, the maximum number of jumps is limited to 30, and the wait time is 4 seconds.
Linux equivalent
The
Linux operating system users can use a utility with broader functionality than the tracert command. It is called traceroute. This application differs from its Windows counterpart in the presence of various modes that are set using parameters.
The tracertroute command with the –I switch implements tracing using ICMP. It is worth noting that to perform this operation, administrator rights are required. With standard settings in most distributions, the tracertroute command can be launched by any user. In this case, they will use UDP packets; you can also force the utility to force them to be specified using the –U parameter.
Asterisks in route output
Very often, the tracert command or its Linux counterpart in a number of places displays information about the response of an asterisk node instead. You should not consider this as a mistake. This means only one thing: a particular router did not respond to a request for a given period of time. There is nothing wrong with this, since there can be many reasons. One of them is the installation of firewalls or other means of protection that block the passage of certain packets.
What should I know about route tracing?
Tracert is a team that is very important in diagnosing network problems. However, it is worth considering that it is quite simple to make a mistake when considering the output of the tracert command. Therefore, do not use route tracking as the only troubleshooting tool.
Another reason that tracing can only indirectly indicate a problem is the difference in the routes for packet packets on the Internet in different directions. As a rule, the packet sent by the user to the server goes through one node, and the packet sent back is completely different.
Packet delays present in the output of the tracert or traceroute utility have nothing to do with delays for transit packets. This is due to the specifics of their processing on the router. Therefore, to focus on them, you must be able to correctly read the output of the command, which is quite difficult.
MTR Utility
MTR exists in versions for most operating systems. The principle of its operation is very similar to the tracer (traceroute) command. It polls a given node for a certain period of time, while allowing you to record changes in delays.
The version of the utility for Windows is called WinMTR and is distributed free of charge.
The user is given the opportunity to work with a graphical interface in which you must specify the IP address or domain of the destination node, and start collecting statistics. As a rule, a minimum of 100 packets must be sent for analysis.
Linux users will also have to install MTR additionally from the repositories. These operating systems typically use the console version of the utility. A variety of parameters are available to the user, allowing you to set the number of sent packets, write a report to a file, or timeout. Also, the Linux version can use certain ports or TCP packets for testing.
What should be sent to the provider to diagnose network problems?
As a rule, it is better for the server administrator or provider to send the tracert (traceroute), ping, and MTR utility report output. You can, of course, try to get by with only the latter, but the more information is provided, the easier it is for a specialist to find and fix the problem.