RFC 3609 (rfc3609) - Page 3 of 9

Tracing Requirements for Generic Tunnels

RFC 3609        Tracing Requirements for Generic Tunnels  September 2003


3.  Application Requirements

   Network operators require a new route-tracing application.  The new
   application must support all functionality that traceroute currently
   offers.  It also must provide enhanced tunnel tracing capabilities.

   The following list provides specific requirements for the new
   route-tracing application:

      1) Support the notion of a security token as part of the tunnel
      trace request.  The security token identifies the tracer's
      privileges in tracing tunnels.  Network elements will use this
      security token to determine whether or not to return the requested
      information to the tracer.  In particular, appropriate privileges
      are required for items (2), (3), (6), (8), (10), (13), and (14).

      Justification: Operators may need to discover network forwarding
      details, while concealing those details from unauthorized parties.

      2) Support in-line traces.  An in-line trace reveals the path
      between the host upon which the route-tracing application executes
      and any interface in an IP network.

      Justification: Operators need to discover how the network would
      forward a datagram between any two IP interfaces.

      3) Support third-party traces.  A third-party trace reveals the
      path between any two points in an IP network.  The application
      that initiates a third-party trace need not execute upon a host or
      router that is part of the traced path.  Unlike existing solutions
      [RFC-2151] [RFC-2925], the application will not rely upon IP
      options or require access to the SNMP agent in order to support
      third-party traces.

      Justification: Operators need to discover how the network would
      forward a datagram between any two IP interfaces.

      4) Support partial traces through broken paths or tunnels.

      Justification: Operators need to identify the root cause of
      forwarding plane failures.

      5) When tracing through a tunnel, either as part of an in-line
      trace or a third-party trace, display the tunnel either as a
      single IP hop or in detail.  The user's request determines how the
      application displays tunnels, subject to the user having
      permission to do this.




Bonica, et al.               Informational