Ever wonder how tracert works?

If you've ever used tracert from a command line, chances are you've never really wondered how it works. Would it surprise you to know that it's actually a series of errors creating the report for you? What happens is that when you type a trace such as c:\>tracert tek-tips.com what you are seeing is a problem routers are having. The tracert command starts by sending a packet with a time to live of 1, so when it gets to the first router, it recieves the packet, which then dies and sends an error back to you, thereby giving the ip/hostname. The next packet sent out has a ttl of 2, so when it reaches the second router, it also dies and sends back the ip/hostname. This continues until you've either reached the destination of the tracert, or the trace dies out. Useless but nifty info.