Traceroute is a very important and useful tool for observing and diagnosing network behavior. It can show you the route data packets are taking across a network, and how well they're making the trip, by, in effect, incrementally pinging each successive hop.

Your computer probably came with a traceroute (or tracert) command, and you can use it any time to see how well your packets are making the trip to whatever destination you specify. Typically this target destination can be provided as either a machine/domain name or as an IP address. Examples include: smtp.whitehouse.gov, cnn.com, ec2-3-135-190-232.us-east-2.compute.amazonaws.com, and 216.157.66.143

By using a gateway to someone else's traceroute, you can see how well packets are making the trip from that person's server to you (which is usually a different route than the one your packets of data take to reach it!), or whatever destination you provide.

Also, you can use such gateways to establish that your web site is reachable from other locations if you suspect a "can't get there from here" condition may exist for some geographical areas. This is also a handy way to check another server's DNS when your ISP's is suspect, such as when changing web hosts and some users are finding the new host while others are still being pointed to the old host.

So it's a nice thing for 'netizens to set up traceroute gateways, and there are hundreds -- maybe thousands -- of them. I wanted mine to be the nicest one on the internet, so it has a few extra bells and whistles not (yet!) found on most (any?) others:

• Integrated Links:
  • Each hop's IP address can be looked up via major internic registry whois databases
  • A whois lookup for a provided IP address, in case the target cannot be reached
  • The provided name, or portion thereof, that looks like it might be reachable from a web browser
  • The final destination name, if you provided an IP address, and/or it looks particularly web-friendly
• 1X / 3X switch:
  • 1 query per hop is usually enough to trace the route, and saves time
  • 3 queries per hop is better for observing network behavior
  • If a different machine replies, it appears on its own line, for improved readability.
• Complete time stamp accompanies each trace.
• Subsequent traces to same target are cached separately in your browser for review.
• Fully configurable for full/open access (including target via URL) based upon hostname (user's domain) and referring document's domain.
• As a configurable option, trace will be automatically halted after X nonresponsive hops.
  • Whenever that occurs, a link is provided to re-trace with auto-halt disabled.
• User-friendly hacker-unfriendly input processing.
• Trace outcome confirmation: complete/unfindable/exhausted/halted
• Takes advantage of, but does not require, a JavaScript-enabled browser:
  • Input field comes up with default text already selected, ready for action.
  • Browser will automatically scroll down at the end of a long trace.
  • ME button:
    • Select your own internet connection as the target with a single click.
    • Restore the previous/default target with a second click.

More information on traceroute: