What is a Traceroute?

What is a Traceroute? Traceroute is a procedure of receiving information about routers or nodes through which packages are transported to specify computer. It permits to detect routing errors by using communication protocols, such as UDP, TCP, GRE or ICMP.

Why do we need a Traceroute?

Sometimes one or another website can be inaccessible by different reasons, for example:

  • troubles with a server (including technical activities);
  • ISP incapability;
  • channel disturbances and failures;
  • browser errors;
  • IP address lock-out.

Traceroute utility identifies a situation and makes for routing with the indication of a target port. The mechanism is based on forwarding of UDP fragments and receiving messages about port availability or unattainability.

Tracerouting process

Host generates a UDP fragment, encapsulates it in an IP package and appoints ttl=1 (time of live or an extreme timeframe or transition counts counting life cycle of a data package). As a transit node, Router1 answers for a specify package with a message about TTL ending. Receiving this info, traceroute tool specifies an address of the source (it’s Router1) as a location of a primary host. In the following, the process repeats with TTL package incrementation.  

For example, UDP fragment is sent from 66600 to 33434 port which is used by default. Receiving a package, Server1 processes it and transmits unpacked data to higher level protocols.  As a 3343 port is closed, Server 1 forms a message about its inaccessibility (ICMP Type 3 «Destination Unreachable» Code 3 «Port Unreachable»). Traceroute tool receives this info and finishes routing process where a number of target port increments at every attempt (33434, 33435, 33436 etc).  

Traceroute on a Windows OS

  1. Click “Start” and then “Run”. In the displayed field write “cmd” without quotation marks and press “Ok” or “Enter” on a keyboard.
  2. In the appeared command line type “tracert address of targeted website, for example: tracert myipcervices.com, and press “Enter”.
  3. Resulting info can be sent to technical support. In this regard, aim a mouse cursor to the command line containing traceroute results and select all text. Press “Enter” storing data in an exchange buffer.

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