'Traceproto' is a traceroute replacement (the original traceroute was written before most firewalls and transparent redirection and often fails when tracing today's networks). that lets users specify the protocol and port to trace to. It currently supports TCP, UDP, and ICMP traces. 'TraceProto' sends packets with a modified time-to-live (ttl) field. As the packets move toward the destination, each hop decrements the time-to-live. If the ttl reaches 0 before the packet reaches its destination (in normal network traffic it is unusual for the ttl to reach 0 before the packet reaches it destination), the hop that did the final decrement sends back an icmp packet informing the source that the packet expired before reaching its destination. TraceProto uses a series of packets with smaller ttl values, so that each hop between the source and the destination responds.
released on 23 February 2005
This entry (in part or in whole) was last reviewed on 9 January 2017.