Internet Engineering Task Force (IETF)                  B. Haberman, Ed.
Request for Comments: 5943                                       JHU APL
Category: Standards Track                                    August 2010
ISSN: 2070-1721


 A Dedicated Routing Policy Specification Language Interface Identifier
                        for Operational Testing

Abstract

   The deployment of new IP connectivity typically results in
   intermittent reachability for numerous reasons that are outside the
   scope of this document.  In order to aid in the debugging of these
   persistent problems, this document proposes the creation of a new
   Routing Policy Specification Language attribute that allows a network
   to advertise an IP address that is reachable and can be used as a
   target for diagnostic tests (e.g., pings).

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc5943.

Copyright Notice

   Copyright (c) 2010 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 2
   2.  RPSL Extension for Diagnostic Address . . . . . . . . . . . . . 2
   3.  Using the RPSL Pingable Attribute . . . . . . . . . . . . . . . 3
   4.  Security Considerations . . . . . . . . . . . . . . . . . . . . 3
   5.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . 4
   6.  Normative References  . . . . . . . . . . . . . . . . . . . . . 4

1.  Introduction

   The deployment of new IP connectivity typically results in
   intermittent reachability for numerous reasons that are outside the
   scope of this document.  In order to aid in the debugging of these
   persistent problems, this document proposes the creation of a new
   Routing Policy Specification Language attribute [RFC4012] that allows
   a network to advertise an IP address that is reachable and can be
   used as a target for diagnostic tests (e.g., pings).

   The goal of this diagnostic address is to provide operators a means
   to advertise selected hosts that can be targets of tests for such
   common issues as reachability and Path MTU discovery.

   The capitalized key words "MUST", "MUST NOT", "REQUIRED", "SHALL",
   "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in
   [RFC2119].

2.  RPSL Extension for Diagnostic Address

   Network operators wishing to provide a diagnostic address for their
   peers, customers, etc., MAY advertise its existence via the Routing
   Policy Specification Language [RFC4012] [RFC2622].  The pingable
   attribute is a member of the route and route6 objects in the RPSL.
   The definition of the pingable attribute is shown in Figure 1.

   +-----------+-------------------+--------------+
   | Attribute |       Value       |    Type      |
   +-----------+-------------------+--------------+
   |  pingable | <ipv6-address> or |  optional,   |
   |           | <ipv4-address>    | multi-valued |
   +-----------+-------------------+--------------+
   |  ping-hdl |   <nic-handle>    |  optional,   |
   |           |                   | multi-valued |
   +-----------+-------------------+--------------+

                Figure 1: Pingable Attribute Specification

   The exact definitions of <ipv4-address> and <nic-handle> can be found
   in [RFC2622], while the definition of <ipv6-address> is in [RFC4012].

   The pingable attribute allows a network operator to advertise an IP
   address of a node that should be reachable from outside networks.
   This node can be used as a destination address for diagnostic tests.
   The address specified MUST fall within the IP address range
   advertised in the route/route6 object containing the pingable
   attribute.  The ping-hdl provides a link to contact information for
   an entity capable of responding to queries concerning the specified
   IP address.  An example of using the pingable attribute is shown in
   Figure 2.

   route6: 2001:DB8::/32
   origin: AS64500
   pingable: 2001:DB8::DEAD:BEEF
   ping-hdl: OPS4-RIPE

                   Figure 2: Pingable Attribute Example

3.  Using the RPSL Pingable Attribute

   The presence of one or more pingable attributes signals to network
   operators that the operator of the target network is providing the
   address(es) for external diagnostic testing.  Tests involving the
   advertised address(es) SHOULD be rate limited to no more than ten
   probes in a five-minute window unless prior arrangements are made
   with the maintainer of the attribute.

4.  Security Considerations

   The use of routing registries based on RPSL requires a significant
   level of security.  In-depth discussion of the authentication and
   authorization capabilities and weaknesses within RPSL is in
   [RFC2725].  The application of authentication in RPSL is key
   considering the vulnerabilities that may arise from the abuse of the
   pingable attribute by nefarious actors.  Additional RPSL security
   issues are discussed in the Security Considerations sections of
   [RFC2622] and [RFC4012].

   The publication of this attribute only explicitly signals the
   availability of an ICMP Echo Request/Echo Response service on the
   specified IP address.  The operator, at his/her discretion, MAY
   deploy other services at the same IP address.  These services may be
   impacted by the ping service, given its publicity via the RPSL.

   While this document specifies that external users of the pingable
   attribute rate limit their probes, there is no guarantee that they
   will do so.  Operators publicizing a pingable attribute are
   encouraged to deploy their own rate limiting for the advertised IP
   address in order to reduce the risk of a denial-of-service attack.
   Services, protocols, and ports on the advertised IP address should be
   filtered if they are not intended for external users.

5.  Acknowledgements

   Randy Bush and David Farmer provided the original concept for the
   pingable attribute and useful comments on preliminary versions of
   this document.  Joe Abley provided comments that justified moving the
   attribute to the route/route6 object and the inclusion of a point of
   contact.  Larry Blunk, Tony Tauber, David Harrington, Nicolas
   Williams, Sean Turner, and Peter Saint-Andre provided useful comments
   to improve the document.

6.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2622]  Alaettinoglu, C., Villamizar, C., Gerich, E., Kessens, D.,
              Meyer, D., Bates, T., Karrenberg, D., and M. Terpstra,
              "Routing Policy Specification Language (RPSL)", RFC 2622,
              June 1999.

   [RFC2725]  Villamizar, C., Alaettinoglu, C., Meyer, D., and S.
              Murphy, "Routing Policy System Security", RFC 2725,
              December 1999.

   [RFC4012]  Blunk, L., Damas, J., Parent, F., and A. Robachevsky,
              "Routing Policy Specification Language next generation
              (RPSLng)", RFC 4012, March 2005.

Author's Address

   Brian Haberman (editor)
   Johns Hopkins University Applied Physics Lab
   11100 Johns Hopkins Road
   Laurel, MD  20723-6099
   US

   Phone: +1 443 778 1319
   EMail: brian@innovationslab.net