draft-ietf-ccamp-tracereq-00.txt   draft-ietf-ccamp-tracereq-01.txt 
Internet Draft R. Bonica Internet Draft R. Bonica
Expiration Date: February 2003 WorldCom Expiration Date: October 2003 WorldCom
K. Kompella K. Kompella
Juniper Networks Juniper Networks
D. Meyer D. Meyer
Sprint Sprint
August 2002 April 2003
Tracing Requirements for Generic Tunnels Tracing Requirements for Generic Tunnels
draft-ietf-ccamp-tracereq-00 draft-ietf-ccamp-tracereq-01
1. Status of this Memo Status of this Memo
This document is an Internet-Draft and is in full conformance with This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of [RFC-2026]. all provisions of Section 10 of RFC-2026.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet- other groups may also distribute working documents as Internet-
Drafts. Internet-Drafts are draft documents valid for a maximum of Drafts. Internet-Drafts are draft documents valid for a maximum of
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reference material or to cite them other than as "work in progress." reference material or to cite them other than as "work in progress."
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2. Abstract Abstract
This document specifies requirements for a generic route-tracing This document specifies requirements for a generic route-tracing
application. It also specifies requirements for a protocol that will application. It also specifies requirements for a protocol that will
support the generic route-tracing application. support the generic route-tracing application. Network operators will
use the generic route-tracing application to verify proper operation
3. Conventions used in this document of the IP forwarding plane. They also use the generic route-tracing
application to discover details regarding tunnels that support IP
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", forwarding.
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC-2119].
4. Introduction 1. Introduction
Currently, the IETF supports several tunneling technologies. Currently, the IETF supports several tunneling technologies.
Although these tunneling technologies provide operators with many Although these tunneling technologies provide operators with many
useful features, they also present management challenges. Operators useful features, they also present management challenges. Operators
require a generic route-tracing application that they can use to require a generic route-tracing application that they can use to
verify tunnel paths and diagnose tunnel faults. verify tunnel paths and diagnose tunnel faults.
This document specifies requirements for that generic route-tracing This document specifies requirements for that generic route-tracing
application. It also specifies requirements for a protocol that will application. It also specifies requirements for a protocol that will
support the generic route-tracing application. support the generic route-tracing application. Network operators will
use the generic route-tracing application to verify proper operation
of the IP forwarding plane. They also use the generic route-tracing
application to discover details regarding tunnels that support IP
forwarding.
5. Review of Existing Functionality 2. Review of Existing Functionality
Currently, network operators use "traceroute" to identify the path Currently, network operators use "traceroute" to identify the path
toward any destination in an IP network. Section 3.4 of [RFC-2151] toward any destination in an IP network. Section 3.4 of [RFC-2151]
provides a thorough description of traceroute. Although traceroute provides a thorough description of traceroute. Although traceroute
is very reliable and very widely deployed, it is deficient with is very reliable and very widely deployed, it is deficient with
regard to tunnel tracing. regard to tunnel tracing.
Depending upon tunnel type, traceroute may display an entire tunnel Depending upon tunnel type, traceroute may display an entire tunnel
as a single IP hop, or it may display a tunnel as a collection of IP as a single IP hop, or it may display a tunnel as a collection of IP
hops, without indicating that they are part of a tunnel. hops, without indicating that they are part of a tunnel.
skipping to change at line 83 skipping to change at line 85
as a single IP hop, hiding all components except the tail-end as a single IP hop, hiding all components except the tail-end
interface. interface.
Now assume that engineers deploy MPLS in an IP network. Assume also Now assume that engineers deploy MPLS in an IP network. Assume also
that engineers configure an MPLS LSP so that the ingress router that engineers configure an MPLS LSP so that the ingress router
propagates the TTL value from the IP header to the MPLS header. When propagates the TTL value from the IP header to the MPLS header. When
engineers trace routes through the network, traceroute will display engineers trace routes through the network, traceroute will display
the LSP as a series of IP hops, without indicating that they are part the LSP as a series of IP hops, without indicating that they are part
of a tunnel. of a tunnel.
6. Application Requirements 3. Application Requirements
Network operators require a new route-tracing application. The new Network operators require a new route-tracing application. The new
application must provide all functionality that traceroute currently application must provide all functionality that traceroute currently
provides. It also must provide enhanced tunnel tracing capabilities. provides. It also must provide enhanced tunnel tracing capabilities.
The following list provides specific requirements for the new route- The following list provides specific requirements for the new route-
tracing application: tracing application:
1) Support the notion of a security token as part of the tunnel 1) Support the notion of a security token as part of the tunnel
trace request. The security token identifies the tracer's trace request. The security token identifies the tracer's
privileges in tracing tunnels. Network elements will use this privileges in tracing tunnels. Network elements will use this
security token to determine whether or not to return the requested security token to determine whether or not to return the requested
information to the tracer. In particular, appropriate privileges information to the tracer. In particular, appropriate privileges
are required for items (2), (3), (5), (8), (12), and (13). are required for items (2), (3), (5), (8), (9), (12), and (13).
2) Support in-line traces. An in-line trace reveals the path 2) Support in-line traces. An in-line trace reveals the path
between the host upon which the route-tracing application executes between the host upon which the route-tracing application executes
and any interface in an IP network. and any interface in an IP network.
3) Support third party traces. A third party trace reveals the 3) Support third party traces. A third party trace reveals the
path between any two points in an IP network. The application path between any two points in an IP network. The application
that initiates a third party trace need not execute upon a host or that initiates a third party trace need not execute upon a host or
router that is part of the traced path. 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.
4) When tracing through a tunnel, either as part of an in-line 4) When tracing through a tunnel, either as part of an in-line
trace or a third party trace, display the tunnel either as a 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 single IP hop or in detail. The user's request determines how the
application displays tunnels, subject to the user having application displays tunnels, subject to the user having
permission to do this. permission to do this.
5) When displaying a tunnel in detail, include the tunnel type 5) When displaying a tunnel in detail, include the tunnel type
(e.g., GRE, MPLS), the tunnel name (if applicable) and the tunnel (e.g., GRE, MPLS), the tunnel name (if applicable) and the tunnel
identifier (if applicable). Also, include tunnel components and identifier (if applicable). Also, include tunnel components and
skipping to change at line 150 skipping to change at line 155
tunnel engages in TTL propagation. (That is, support tunnel tunnel engages in TTL propagation. (That is, support tunnel
tracing regardless of whether the TTL value is copied from an tracing regardless of whether the TTL value is copied from an
inner header to an outer header at tunnel ingress). inner header to an outer header at tunnel ingress).
12) When tracing through the control plane, display the MTU 12) When tracing through the control plane, display the MTU
associated with each hop. associated with each hop.
13) When tracing through the forwarding plane, display the MTU 13) When tracing through the forwarding plane, display the MTU
associated with each hop in the reverse direction. associated with each hop in the reverse direction.
7. Protocol Requirements 4. Protocol Requirements
Implementers require a new protocol that supports the application Implementers require a new protocol that supports the application
described above. This protocol reveals the path between two points described above. This protocol reveals the path between two points
in an IP network. When access policy permits, the protocol also in an IP network. When access policy permits, the protocol also
reveals tunnel details. reveals tunnel details.
7.1. Information Requirements 4.1. Information Requirements
The protocol consists of probes and probe responses. Each probe The protocol consists of probes and probe responses. Each probe
elicits exactly one response. Each response represents a hop that elicits exactly one response. Each response represents a hop that
connects the head-end of the traced path to the tail-end of the connects the head-end of the traced path to the tail-end of the
traced path. A hop can be either a top-level IP hop or lower-level traced path. A hop can be either a top-level IP hop or lower-level
hop that is contained by a tunnel. hop that is contained by a tunnel.
7.2. Transport Layer Requirements 4.2. Transport Layer Requirements
UDP carries all protocol messages to their destinations. UDP carries all protocol messages to their destinations.
7.3. Routing Requirements 4.3. Routing Requirements
The device that hosts the route-tracing application must maintain an The device that hosts the route-tracing application must maintain an
IP route to the head-end of the traced path. It must also maintain an IP route to the head-end of the traced path. It must also maintain an
IP route to the head-end of each tunnel for which it is requesting IP route to the head-end of each tunnel for which it is requesting
tunnel details. The device that hosts the tunnel tracing application tunnel details. The device that hosts the tunnel tracing application
need not maintain a route to any other device that supports the need not maintain a route to any other device that supports the
traced path. traced path.
All of the devices mentioned above must maintain an IP route back to All of the devices mentioned above must maintain an IP route back to
the device that hosts the route tracing application. the device that hosts the route-tracing application.
In order for the protocol to provide tunnel details, all devices In order for the protocol to provide tunnel details, all devices
contained by a tunnel must maintain an IP route to the device that contained by a tunnel must maintain an IP route to the tunnel
hosts the tunnel ingress. ingress.
7.4. Maintaining State 4.4. Stateless Protocol
The protocol must be stateless. That is, no node should have to The protocol must be stateless. That is, no node should have to
maintain state between successive traceroute messages. maintain state between successive traceroute messages.
8. Security Considerations 5. Security Considerations
A configurable access control policy determines the degree to which A configurable access control policy determines the degree to which
features described herein are delivered. The access control policy features described herein are delivered. The access control policy
requires user identification and authorization. requires user identification and authorization.
As stated above, the new protocol must not introduce security holes As stated above, the new protocol must not introduce security holes
nor consume excessive resources (e.g., CPU, bandwidth). It also must nor consume excessive resources (e.g., CPU, bandwidth). It also must
not be exploitable by those launching DoS attacks. not be exploitable by those launching DoS attacks or replaying
messages.
9. Normative References
[RFC-2119], Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, Harvard University, March 1997
10. Informative References
[RFC-2026], Bradner, S., "Internet Standards Process Revision 3", RFC 6. Informative References
2026, Harvard University, October 1996.
[RFC-2151], Kessler, G., Shepard, S., A Primer On Internet and TCP/IP [RFC-2151], Kessler, G., Shepard, S., A Primer On Internet and TCP/IP
Tools and Ut ilities, RFC 2151, Hill Associates, Inc., June 1997 Tools and Ut ilities, RFC 2151, Hill Associates, Inc., June 1997
[RFC-2434] T. Narten and H. Alvestrand, "Guidelines for Writing an [RFC-2925], White, K., "Definitions of Managed Objects for Remote
IANA Considerat ions Section in RFCs", RFC 2434, October, 1998. Ping, Traceroute, and Lookup Operations", RFC 2925, September, 2000.
[RFC-2637] Hamzeh, K. et. al., "Point-to-Point Tunneling Protocol
(PPTP)", RFC 263 7, July, 1999.
11. Acknowledgements 7. Acknowledgements
Thanks to Randy Bush and Steve Bellovin for their comments. Thanks to Randy Bush and Steve Bellovin for their comments.
12. Author's Addresses 8. Author's Addresses
Ronald P. Bonica Ronald P. Bonica
WorldCom WorldCom
22001 Loudoun County Pkwy 22001 Loudoun County Pkwy
Ashburn, Virginia, 20147 Ashburn, Virginia, 20147
Phone: 703 886 1681 Phone: 703 886 1681
Email: rbonica@mci.net Email: rbonica@mci.net
Kireeti Kompella Kireeti Kompella
Juniper Networks, Inc. Juniper Networks, Inc.
1194 N. Mathilda Ave. 1194 N. Mathilda Ave.
Sunnyvale, California 94089 Sunnyvale, California 94089
Email: kireeti@juniper.net Email: kireeti@juniper.net
Dave Myers Dave Myers
Email: dmm@sprint.net Email: dmm@sprint.net
13. Full Copyright Statement 9. Full Copyright Statement
Copyright (C) The Internet Society (2000). All Rights Reserved. Copyright (C) The Internet Society (2000). All Rights Reserved.
This document and translations of it may be copied and furnished to This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph are kind, provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing document itself may not be modified in any way, such as by removing
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