Network Monitoring Software - Trace Route - PingCOPA

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TCP/IP was never designed to provide information about the route that packets take to their destination: The PingCOPA network monitoring software Trace Route function provides a simple but imperfect means of assembling this information.

 

It is dependent on packets being returned by each machine on the route, which may not be the case - they may not return pings to prevent their being seen on the network, or because they  de-prioritise pings at busy times. The PingCOPA Network monitoring software Trace Route function may therefore only produce partial information about the route.

 

Two types of packets are used in Trace Route - The PingCOPA network monitoring software supports two methods of PING, ICMP (the official method), and UDP. Some routers respond to one, or the other, or both. We provide both methods so that there is more chance of a route being detectable because of firewall issues along the route. UDP packets and ICMP packets may take a different route depending on router configuration along the way.

 

The technique is to send packets with different TTL (Time To Live) - the TTL is reduced by 1 by each router it passes, and will not be forwarded further once it reaches zero. However, routers often return such packets to their source showing their IP address as the last point reached.

 

Thus, a packet is sent to the final destination with a TTL of 1 - this will be returned by the first router.

 

Then a packet is sent to the final destination with a TTL of 2 - this will be returned by the second router.

 

And so on ... Thus the route can be assembled, as shown below.

 

Click a hotspot on the image below for further information.

 

trace_route