How does tracert find the route

Log in. Article Content. What is Tracert? What is Traceroute? How do I use Tracert? To use tracert, you must be running Microsoft Windows. Interpreting the results Each entry, or hop , is a location that the packet passes through to reach its final destination.

Trace complete. URL Name. Last Modified Date. Terms Privacy. The command:. In the following example, the default gateway has found that there is no valid path for the host on Probably, either the router has a configuration problem, or the Trace complete. TRACERT is useful for troubleshooting large networks where several paths can lead to the same point or where many intermediate components routers or bridges are involved. There are several command-line options that you can use with TRACERT, although the options are not usually necessary for standard troubleshooting.

The following example of command syntax shows all of the possible options:. Windows Server More Need more help? Expand your skills. Get new features first. So if there is a loop, since each router decrements the TTL value, at one point, it goes to 0 and gets discarded. So the traceroute software uses the TTL to discover the routers between a source and a destination. The Router decrements the TTL by 1, which changes the value to 0.

The source IP address of the discarded packet is the IP address of the interface on which the packet was received. The packet is routed through the first Router R1 , which also decrements the packet value.

And it continues like this by incrementing the TTL by 1 until it reaches its destination. The latency measured for each router in the trace is the time difference between when the message is sent and when the TTL exceeded message is received.

So if a router never sends the message, it will not be discovered in the traceroute, but since it is still decrementing the TTL value, it will count as an unknown hop in the trace.

This is the end of this first article on traceroutes. Now that you know how traceroutes work, the next articles will cover how to analyze traceroutes, how to read a traceroute, and which information is the most important. Learn how to identify network issues with Traceroutes by analyzing Traceroute metrics latency, packet loss and hops.