Tracing Requirements for Generic Tunnels

This document specifies requirements for a generic route-tracing application. It also specifies requirements for a protocol that will support that application. Network operators will use the generic route-tracing application to verify proper operation of the IP forwarding plane. They will also use the application to discover details regarding tunnels that support IP forwarding. The generic route-tracing application, specified herein, supports a superset of the functionality that "traceroute" currently offers. Like traceroute, the generic route-tracing application can discover the forwarding path between two interfaces that are contained by an IP network. Unlike traceroute, this application can reveal details regarding tunnels that support the IP forwarding path.