traceroute

Traceroute is a test program that can be used to determine the routes through the Internet, comparable to the ping method. Traceroute determines which connections and Internet nodes were used to establish the connection to the target computer.

Traceroute or Tracert works with the ICMP protocol and sends IP data packets to the target computer. Before the routers count down the time-to-live( TTL) data field and then forward it, they evaluate it and send the ICMP response for the TTL value and the transmission duration back to the source address( SA) entered in the IP data packet. The test is performed several times with the TTL value constantly increased by the amount 1 until the data packet has reached the destination address and all Internet nodes with their transmission times have been recorded.

The traceroute procedure varies somewhat depending on the operating system. Windows, for example, works with ICMP packets and tracert.exe, while Unix uses the UDP protocol and there are separate implementations for the TCP protocol: Tcptraceroute or Layer Four Traceroute (LFT).