Traceroute program lets us to see the route of IP datagram which follows from one Internet host to other. The first implementation of Traceroute belongs to Van Jacobson. He wrote it from a suggestion by Steve Deering. Some details about traceroute and other network tools are on the site of Berkley's Network Research Group staff that Van Jackobson worked for. Other version of traceroute MTR was implemented by Matt Kimball. MTR combines the functionality of the traceroute and ping programs in a single network diagnostic tool and contains also the graphical version. Of course, all these tools were implemented for Unix and are easy accessible for getting sources and instalation. About Microsoft case of Traceroute Applications see, for example, on the site Microsoft Internet Control Message Protocol.

URL: Max Hops:  Table Output Flush Stream If you select table output be patient. The traceroute output page will be prepared in  10-15 sec.   You can also select  flush stream  mode to get results  on the fly.  The default  maximal  hops   value is equal to 30. Maybe  you  need to touch it ...  At last,   the  mode Route to you  sends pings to your host,   hopefully it's not unreachable.

The idea of Traceroute is to use TTL field (time-to-live) in the IP header. See Tracing the Path of a TCP/IP Packet about ICMP protocol and TTL field. Each router that gets the datagram decrements TTL by one, so the TTL becomes a hop counter. Some descriptions about traceroute algorithm may be found on the site How traceroute works.     Original Traceroute sends by default 3 probe datagrams and this Tracerote Servlet save this tradition. If one of the probe datagrams gets lost it will be marked by asterisk * in the output result. It's very hard to find the site so that it will take you more 20 hops to get there. The maximal value for TTL field is 255. The default maximal hop value in the Traceroute Servlet is taken 30 as in the most traceroute services. You can find one ancient example of 38 (!) hops. There are some buggy routers that forwards the datagram packet with a zero TTL. It sometimes leads to Routing Loop. The Traceroute Servlet will stop the tracing process if the current IP address is repeating 3 times.

    There are many traceroute services on the Internet that lets us to trace datagramm passing through the Web from different places. See, for example,  Index of Traceroute Web Servers ,  Traceroute Gateway ,  Multiple Traceroute ,  Geektools Traceroute or  Traceroute List.
    This servlet uses JNI (Java Native Interface) because the communication engine is written by C. The further information about JNI see on the RingLord Technologies site or in the Essential JNI book by Rob Gordon. Some others Traceroute tools using Java may be found on the  Traceroute Animation and  Visualroute  sites.

---

My special acknowledgments to Leonid Kaminsky and Sergey Nikhinson for helping
and supporting to implement this servlet and others of the site Imagined Cities.

This servlet implemented and maintained by Rafael Stekolshchik klivlend1@yahoo.com