A Note on Traceroute

Traceroute is a clever tool that allows network administrators to isolate and debug complex network problems. It's also a critical tool for folks interested in how the Internet is connected together. It's available on most Unix systems and on many Windows installations. From a Unix shell, the command is "traceroute n" where n is either a domain name or an IP address. On a Windows system, select "Run" from the start menu. Type "Command" into the "Open:" window and hit Okay to open a shell window. At the C: prompt, type "tracert n", where n is either a domain name or an IP address.

If you don't have access to traceroute on your local system, you're not out of luck. There are some terrific online traceroute tools that allow you to trace the routes from different internet backbones to an arbitrary host. These tools are often very helpful even if you have a local instance of traceroute, as traceroute only allows you to trace from your system to another host. If you're trying to do network mapping, it's important to be able to trace paths between two arbitrary machines, and these online tools can help you do this.

Should you be lucky enough to have access to a good Unix shell, you may also find the "whois" and "host" commands useful. Whois is most useful with the -h flag, which allows you to query multiple whois hosts - for instance, when looking up hosts in Asia, it's useful to use the syntax "whois -h whois.apnic.net domainname.com" to query the Asia Pacific whois server.

Happy mapping.