Abstract: Method and apparatus for determining a communications path between a source and a destination in an Internet Protocol (IP) network. The method determines a path list of next-hop routers between the source and destination by selecting between a Simple Network Management Protocol (SNMP) query of a current router on the path, and by sending a User Datagram Protocol (UDP) probe packet having a destination field with a destination IP address and a Time-to-Live (TTL) field with a value of one greater than the number of hops to the current router. The steps are iterated until the next router is determined to be the destination. Preferably, the UDP probe packets are loose-source routed through the source. In addition, a topology information database may be accessed to resolve an unknown router, and/or resolve intrarouter devices on the path.