    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.

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    RFC 5943                 RPSL Pingable Attribute             August 2010

    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

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    RFC 5943                 RPSL Pingable Attribute             August 2010

       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.

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    RFC 5943                 RPSL Pingable Attribute             August 2010

       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

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