Secure Inter-Domain Routing (SIDR)                             G. Huston
Internet-Draft                                             G. Michaelson
Intended status: Informational                                     APNIC
Expires: February 7, September 4, 2010                                 March 3, 2010                                 August 6, 2009

 Validation of Route Origination in BGP using the Resource Certificate PKI and
                                  ROAs
                 draft-ietf-sidr-roa-validation-03.txt
                 draft-ietf-sidr-roa-validation-04.txt

Abstract

   This document defines the semantics of a Route Origin Authorization
   in terms of the context of an application of the Resource Public Key
   Infrastructure to validate the origination of routes advertised in
   the Border Gateway Protocol.

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Abstract

   This  Code Components extracted from this document defines an application of the Resource Public Key
   Infrastructure to validate the origination of routes advertised must
   include Simplified BSD License text as described in Section 4.e of
   the Border Gateway Protocol.  The proposed application is intended to
   fit within the requirement for adding security to inter-domain
   routing, including the ability to support incremental and piecemeal
   deployment, Trust Legal Provisions and does not require any changes to are provided without warranty as
   described in the specification of
   BGP. BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
   2.  ROA Validation Outcomes of for a BGP Route Object  . . . . . . . . . . 3
   3.  Applying Validation Outcomes to BGP Route Selection . . . . .  4
   4.  Further Considerations . . . . . . . . . . . . . . . . . . . .  6
     4.1.  Partial Deployment Considerations  . . . . . . . . . . . .  6
     4.2. 5
   4.  Disavowal of Routing Origination  . . . . . . . . . . . . .  7
     4.3.  BGP Considerations . . . . . . . . . . . . . . . . . . . .  8 6
   5.  Security Considerations  . . . .  Route Object Validation Lifetime  . . . . . . . . . . . . . . .  8 7
   6.  IANA  Security Considerations . . . . . . . . . . . . . . . . . . . . .  9 7
   7.  Change Log . . . . . . . . . . . . . . . . . . . . . . . . . .  9
     7.1.  Changes -02 to -03 . . . . . . . . . . . . . . . . . .  IANA Considerations . .  9
     7.2.  Changes -01 to -02 . . . . . . . . . . . . . . . . . . . . 10 8
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . . . 10 8
     8.1.  Normative References  . . . . . . . . . . . . . . . . . . . 10 8
     8.2.  Informative References  . . . . . . . . . . . . . . . . . . 11 8
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . . 11 8

1.  Introduction

   This document defines the semantics of a Route Origin Authorization
   (ROA) in terms of the context of an application of the Resource
   Public Key Infrastructure (RPKI) [I-D.ietf-sidr-arch] to validate the
   origination of routes advertised in the Border Gateway Protocol (BGP)
   [RFC4271].

   The RPKI is based on a hierarchy of Resource Certificates that are
   aligned to the Internet number resource allocation structure.
   Resource Certificates are X.509 certificates that conform to the PKIX
   profile [RFC5280], and to the extensions for IP addresses and AS
   identifiers [RFC3779].  A Resource Certificate describes an action by
   an issuer that binds a list of IP address blocks and Autonomous
   System (AS) numbers to the Subject of a certificate, identified by
   the unique association of the Subject's private key with the public
   key contained in the Resource Certificate.  The RPKI is structured
   such that each current Resource Certificate matches a current
   resource allocation or assignment.  This is further described in
   [I-D.ietf-sidr-arch].

   Route Origin Authorizations (ROAs)

   ROAs are digitally signed objects that bind an address to an AS
   number, signed by the address holder.  A ROA provides a means of
   verifying that an IP address block holder has authorized an a particular
   AS to originate route objects in the inter-domain routing environment
   for that address block.  ROAs are described in
   [I-D.ietf-sidr-roa-format].  ROAs are intended to fit within the
   requirements for adding security to inter-domain routing.

   This document describes the semantic interpretation of a valid ROA, with
   particular reference to application in BGP inter-domain routing relating
   to the origination of route objects.

   This proposed application of validation of ROAs does not require any
   changes to objects, and the specification of BGP protocol elements.  The outcomes
   of ROA validation may be used as part intended scope of BGP's local route selection
   procedure [RFC4271]. the
   authority that is conveyed in the ROA.

2.  ROA Validation Outcomes of for a BGP Route Object

   A BGP "route object" is an address prefix and an associated set of
   routing attributes.  In terms of validation of the route object in
   the context of BGP [RFC4271]the address prefix value and the "origin
   AS" are used in the ROA validation operation.  The route object's
   origin AS is the final element of the route object's AS_PATH
   attribute.  If the final AS_PATH element is an AS Set, indicating
   that the route object is an aggregate, then the origin AS is taken as
   the AS component of the AGGREGATOR attribute [RFC4271].

   A BGP route object does not refer to a specific ROA

   It is assumed here that should be
   used by a Relying Party (RP) has access to validate the origination information
   contained in a local
   cache of the complete set of valid ROAs when performing validation of
   a route object.  (Valid ROAs are defined as ROAs that are determined
   to be syntactically correct and are signed using a signature that can
   be verified using the RPKI, as described in
   [I-D.ietf-sidr-roa-format].)  The RP needs to match a route object to
   one or more candidate valid ROAs in order to determine a validation
   outcome, which, in turn, can be used to determine the appropriate
   local actions to perform on the route object.  Valid ROAs
   are defined as ROAs that are determined

   This approach to be syntactically correct
   and are signed using route object origination validation uses a signature model of
   "positive" attestations, where route objects that can cannot be verified using validated
   within the RPKI, RPKI framework would conventionally be treated by a RP as described in [I-D.ietf-sidr-roa-format].  The outcome of this ROA
   validation function is that either
   "invalid".  However, the RP has determined that considerations of accommodating environments
   of partial adoption of the ROA
   is valid in use of ROAs, where only a subset of
   validly advertised address prefixes have associated published ROAs
   within the context structure of the RPKI, or the ROA is invalid, in which
   case the ROA is not imply some modification to be used by the RP.

   It is assumed here that ROAs are managed and distributed
   independently this
   model of positive attestation.  In the operation context of BGP itself, and route object
   validation it is assumed that once an address prefix is described in
   a local BGP
   speaker has access to a local cache of ROA, then this ROA speifically encompasses all address prefixes
   that are more specific than that described in the complete set of valid ROAs
   when performing a ROA.  Thus, any
   route object validation operation.

   Route object validation is defined for more specific address prefix than that described by the following procedure:

      1.  Select all
   any valid ROAs ROA that include does not itself have a ROAIPAddress value that
          either matches, or matching valid ROA is a covering aggregate of, the
   considered to be "invalid".  However, routes objects for address
          prefix in the
   prefixes that are not fully described by any single ROA, i.e., those
   route object.

      2.  If the set of candidate ROAs is empty then the validation
          procedure stops with objects whose address prefixes may be an outcome aggregate of "unknown".

      3.  If any ROA has an asID value that matches the origin AS in the
          route object, and either the route object's address prefix
          precisely matches a ROAIPAddress
   prefixes described in the a valid ROA, or the route
          object's have address prefix prefixes where
   there is no intersection with any ROA, and are not matched by any ROA
   and are not a more specific prefix of any ROA cannot be reliably classified
   as "invalid" in a
          ROAIPAddress and the partial deployment scenario.  Such route object's prefix length value is
          less than or equal to the ROAIPAddress' maxLength value, then
          the objects
   have a validation procedure stops with an outcome of "valid".

      4.  Otherwise, the "unknown".

   The validation procedure stops with an outcome of
          "invalid".

3.  Applying Validation Outcomes to BGP Route Selection

   Within the framework of the abstract model condition of BGP operation, a
   received prefix announcement from route object with a BGP speaking peer is compared to
   all announcements for this prefix received from other BGP peers and a
   route selection procedure is used to select the "best" route object
   from this candidate set.  This route object is then used locally by
   installing it in the loc-RIB [RFC4271], and is announced to peers as
   the local "best" route.

   The route object validation outcome, described in Section 2, of
   "unknown", "valid" or "invalid" may be used as part of the
   determination of the local degree of preference as defined in section
   9.1.1 of the BGP specification [RFC4271].  The local degree of
   preference is as follows:
      "valid" is to be preferred over
      "unknown", which itself is to be preferred over
      "invalid".

   This preference ranking is performed prior to the steps described in
   section 9.1.1 of [RFC4271].

   It is a matter of local BGP selection policy as to the actions to be
   undertaken by a BGP instance in processing route objects with
   "unknown" validation outcomes.  Due to considerations of partial use
   of ROAs in heterogeneous environments, such as in the public
   Internet, it is advised that local policy settings should not result
   in "unknown" validation outcomes being considered as sufficient
   grounds to reject a route object outright from further consideration
   as a local "best" route.

   It is a matter of local BGP selection policy as to whether "invalid"
   route objects are considered to be ineligible for further
   consideration in the route selection process.  The consideration here
   is one of potential circularity of dependence.  If the authoritative
   publication point of the repository of ROAs, or that of any
   certificate used in relation to an address prefix, is located at an
   address that lies within the address prefix described in a ROA, then
   the repository can only be accessed once a route for the prefix has
   been accepted by the RP's local routing domain.  It is also noted
   that the propagation time of RPKI objects may be different to the
   propagation time of route objects in BGP, and that route objects may
   be received before the RP's local repository cache picks up the
   associated ROAs and recognises them as valid within the RPKI.

   A local policy setting may be considered such that "invalid"
   validation outcomes would be sufficient grounds to reject the route
   object.  However, due to these considerations of circular dependence
   and differing propagation times of ROAs and route objects, an
   alternate local policy setting may be considered that would involve
   the use of a local timer to accept the route object as feasible for
   an interim period of time, until there is an acceptable level of
   assurance that all reasonable efforts to obtain a valid ROA for the
   route object have been undertaken.

4.  Further Considerations

4.1.  Partial Deployment Considerations

   This approach to route object origination validation uses a model of
   "positive security" attestations, where information that cannot be
   validated within the RPKI framework is intended to interpreted by a
   RP as invalid information.

   However, the considerations of accommodating environments of partial
   adoption, where only a subset of valid route objects have associated
   ROAs within the structure of the RPKI, imply some modification to
   this model of positive security.  Here it is assumed that once an
   address prefix is described in a ROA, then this ROA encompasses all
   address prefixes that are more specific than that described in the
   ROA.  Thus, any more specific address prefix and originating AS
   combination of a valid ROA, that does not have a matching valid ROA
   is considered to be "invalid".

   Routes objects that describe address prefixes that are not fully
   described by any single ROA, i.e., those address prefixes that may be
   an aggregate of a ROA, or have no intersection with any ROA, and are
   not matched by any ROA and are not a more specific of any ROA cannot
   be reliably classified as "invalid" in a partial deployment scenario,
   and are therefore described as "unknown".

   The match condition of a route object against a single ROA is
   summarized in the following table:

   Prefix      matching   non-matching
               AS         AS
              +---------+-------------+
   Covering   | unknown | unknown     |
   Aggregate  |         |             |
              +---------+-------------+
   match ROA  | valid   | invalid     |
   prefix     |         |             |
              +---------+-------------+
   More       | invalid | invalid     |
   Specific   |         |             |
   than ROA   |         |             |
              +---------+-------------+

   In an environment of a collection of ROAs, a route object is
   considered to be "valid" if any ROA provides a "valid" outcome, and
   "invalid" if one or more ROAs provide an "invalid" outcome and no
   ROAs provide a "valid" outcome.  The "unknown" outcome occurs when no
   ROA produces either a "valid" or an "invalid" outcome.

4.2.  Disavowal of Routing Origination

   A ROA is a positive attestation that a prefix holder has authorized
   an AS to originate a route for this prefix into the inter-domain
   routing system.  It is possible for a prefix holder to attest that no
   AS has been granted any such authority by prefix and an
   origin AS when using a single ROA where the ROA'S
   subject AS for validation is one that will not be used summarized in a routing context.
   Specifically, AS 0 is reserved by the IANA such that it "may be use
   [sic] to identify non-routed networks" [IANA.AS-Registry].

   A ROA with a subject of
   following table:

   Prefix      matching   non-matching
               AS 0 is an attestation by the holder of a
   prefix that the prefix described in the ROA, and any more specific
   prefix, should not be used in a routing context.

   The route object validation procedure, described in Section 2, will
   provide a "valid" outcome if any         AS
              +---------+-------------+
   Covering   | unknown | unknown     |
   Aggregate  |         |             |
              +---------+-------------+
   match ROA matches the address prefix and
   origin AS, even if other  | valid ROAs would provide an "invalid"
   validation outcome if used in isolation.  Consequently, an AS0 ROA
   has a lower preference   | invalid     |
   prefix     |         |             |
              +---------+-------------+
   More       | invalid | invalid     |
   Specific   |         |             |
   than any other ROA that has a routeable AS as
   its subject.  This allows a prefix holder to use   |         |             |
              +---------+-------------+

   In an AS0 ROA to
   declare environment of a collection of ROAs, a default condition that any route object that is equal to,
   or more specific than the prefix to be
   considered to be invalid,
   while also allowing other concurrently issued ROAs to describe valid
   origination authorizations for more specific prefixes.

   For example, the holder of prefix 203.0.113.0/24 may wish to
   authorise the origination of "valid" if any ROA provides a route object of 203.0.113.196/26 by
   64496, and explicitly declare that all other use of prefixes from
   this block should be "valid" outcome.  It
   is considered invalid.  This could to be achieved
   through the issuing of a ROA for Address=203.0.113.0/24,
   maxLength=32, AS = 0 "invalid" if one (or more) ROAs provide an
   "invalid" outcome and no ROAs provide a second ROA for Address=203.0.113.196/26,
   maxLength=26, AS=64496.

   By convention, an AS 0 "valid" outcome.  It is
   considered to be "unknown" when no ROA should have produces either a maxLength value of 32 for
   IPv4 addresses and 128 for IPv6 addresses, although in terms of route "valid" or
   an "invalid" outcome.

   Route object validation is defined by the same outcome would be achieved with any following procedure:

      1.  Select all valid
   maxLength value, ROAs that include a ROAIPAddress value that
          either matches, or even if is a covering aggregate of, the maxLength element were to be omitted
   from address
          prefix in the ROA.  Also by convention, an AS 0 ROA should be route object.

      2.  If the only ROA
   issued for a given address prefix, although again this set of candidate ROAs is not a
   strict requirement.  An AS 0 ROA can coexist empty then the validation
          procedure stops with an outcome of "unknown".

      3.  If any of the selected ROAs has an asID value that have
   different subject matches the
          origin AS values, although in such cases the presence of the AS 0 ROA does not alter route object, and either the route object validation outcome object's
          address prefix precisely matches a ROAIPAddress in
   any way.

4.3.  BGP Considerations

   This document provides the ROA, or
          the route object's address prefix is a description more specific prefix of how ROAs could be used by
          a
   BGP speaker.

   It ROAIPAddress, and the route object's prefix length value is noted that
          less than or equal to the ROAIPAddress' maxLength value, then
          the validation procedure stops with an outcome of "valid".

      4.  Otherwise, the proposed validation procedure requires no changes stops with an outcome of
          "invalid".

3.  Applying Validation Outcomes to Route Selection

   Within the
   operation framework of BGP.  However, there are a number the abstract model of considerations
   about this approach to origination validation that are relevant to the operation of a inter-
   domain routing using BGP speaker that are not specified here.

   These considerations include:

      *  It is not specified when validation of an advertised [RFC4271], a received prefix
         should be performed by announcement
   from a BGP speaker.  It routing peer is considered compared to be all announcements for this prefix
   received from other routing peers and a
         matter of local policy whether it route selection procedure is strictly required to
         perform validation at a point prior
   used to loading select the "best" route object into
         the Adj-RIB-In structure [RFC4271], or once the from this candidate set.

   The route object has been
         loaded into Adj-RIB-In, or at a later time that is determined
         by a local configuration setting.  It is also not specified
         whether origination validation should outcome, described in Section 2, of
   "unknown", "valid" or "invalid" may be performed each time a
         route object is updated by a peer even when used as part of the origin AS has
         not altered.

      *  The lifetime
   determination of a validation outcome is not specified here.
         This specifically refers to the time period during local degree of preference, in which case the
         original validation outcome can be still applied, at the
         expiration
   local order of preference is as follows:
      "valid" is to be preferred over
      "unknown", which the routing object should itself is to be re-tested for
         validity. preferred over
      "invalid".

   It is a matter of local routing policy as to the actions to be
   undertaken by a routing entity in processing route objects with
   "unknown" validation outcomes.  Due to considerations of partial use
   of ROAs in heterogeneous environments, such as in the public
   Internet, it is advised that local policy setting settings should not result
   in "unknown" validation outcomes being considered as sufficient
   grounds to whether reject a validation outcome be regarded as valid until the route object is withdrawn or outright from further updated, or whether validation
         of consideration
   as a route object should occur at more frequent intervals.

      * local "best" route.

   It is a matter of local configuration routing policy as to whether ROA
         validation is performed on a per-AS basis rather than a per-BGP
         speaker, and the appropriate mechanisms "invalid" route
   objects are considered to support be ineligible for further consideration in
   a de-coupled
         framework route selection process.  A possible consideration here is one of validation
   potential circularity of ROAs and dependence.  If the loading authoritative
   publication point of outcomes
         into BGP speakers are not considered here.

5.  Security Considerations

   ROA issuers should be aware the repository of ROAs, or that of any
   certificate used in relation to an address prefix, is located at an
   address that lies within the validation implication address prefix described in issuing a ROA, in that then
   the repository can only be accessed by the RP once a ROA will implicitly invalidate all route objects for
   more specific prefixes with a the
   prefix length greater than maxLength,
   and all originating AS's other than has been accepted by the AS listed in RP's local routing domain.  It is
   also noted that the collection propagation time of ROAs.

   A conservative operational practice would RPKI objects may be different
   to ensure the issuing propagation time of route objects, and that route objects may
   be received before the RP's local repository cache picks up the
   associated ROAs for all more specific prefixes with distinct origination AS's
   prior and recognises them as valid within the RPKI.

4.  Disavowal of Routing Origination

   A ROA is a positive attestation that a prefix holder has authorized
   an AS to originate a route for this prefix into the issuing of ROAs inter-domain
   routing system.  It is possible for larger encompassing address blocks,
   in order a prefix holder to avoid inadvertent invalidation of construct an
   authorization where no valid AS has been granted any such authority
   to originate a route objects
   during ROA generation.

   ROA issuers should also be aware that if they generate object for an address prefix.  This is acheived
   by using a ROA for one
   origin AS, then if where the prefix ROA's subject AS is authorised by multiple AS's then
   ROAs should one that must never be generated for all such authorized AS's.

6.  IANA Considerations

   Dear IANA,

   The
   used in any routing context.  Specifically, AS number registry [IANA.AS-Registry] contains 0 is reserved by the following
   annotation against AS 0:
   IANA such that it "may be use [sic] to identify non-routed
   networks."  Could you please add networks"
   [IANA.AS-Registry].

   A ROA with a 'd' as appropriate to this text?

   Thank you,

   the authors.

7.  Change Log

   Note: This section subject of AS 0 is an attestation by the holder of a
   prefix that the prefix described in the ROA, and any more specific
   prefix, SHOULD NOT to be included used in final version of this
   document.

7.1.  Changes -02 to -03

   Further Considerations section now has a subsection describing the
   assumptions that ROA routing context.

   The route object validation is making about procedure, described in Section 2, will
   provide a "valid" outcome if any ROA matches the precise nature of
   partial deployment, noting that address prefix and
   origin AS, even if other valid ROAs would provide an "invalid"
   validation outcome if used in isolation.  Consequently, an AS 0 ROA
   has a lower preference than any other ROA that has a routeable AS as
   its subject.  This allows a prefix holder to use an implicit scope of
   application for all prefixes AS 0 ROA to
   declare a default condition that are any route object that is equal to,
   or more specific than the prefix to be considered to be invalid,
   while also allowing other concurrently issued ROAs to or describe valid
   origination authorizations for more specific than
   the prefix listed in the ROA

   Moved the table of validation outcomes from the Security
   Considerations section to the section on Further Considerations.

   Added consideration about disavowal and the use of prefixes.

   By convention, an AS 0 ROA SHOULD have a maxLength value of 32 for
   IPv4 addresses and
   its interpretation 128 for IPv6 addresses, although in the context of validation terms of route objects, and
   proposed conventions of use of
   object validation the same outcome would be achieved with any valid
   maxLength value, or even if the maxLength element were to be omitted
   from the ROA.

   Also by convention, an AS 0 ROA.

   Noted hierarchical dependence of ROA issuance in the Security
   Considerations section.

7.2.  Changes -01 to -02

   Following WG review of the means of specification of denial in
   routing authorizations in the context of SHOULD be the RPKI at IETF 74 and IETF
   75, it appears that there is no general WG support only ROA issued for the use of an
   explicit denial object (termed a 'BOA').  The alternative approach,
   explored in previous iterations of
   given address prefix, although again this draft, used a more restricted
   interpretation of is not a strict
   requirement.  An AS 0 ROA can coexist with ROAs that yielded only "valid" or "unknown"
   outcomes (by using "unknown" where "invalid" is used have different
   subject AS values, although in this revision
   of the document).  To allow for "invalid" outcomes such cases the draft used presence of the
   BOA to undertake AS 0
   ROA does not alter the role of a 'disavow' constraint, where a route object was considered to be "invalid" if it was the subject of a
   valid BOA and was not considered to be "valid" by validation outcome in any valid ROA. way.

5.  Route Object Validation Lifetime

   The
   reasons advanced to support the dropping "lifetime" of a validation outcome refers to the BOA was time period
   during which the increased
   complexity of RP systems through original validation outcome can be still applied.
   The implicit assumption here is that when the use of a second validation lifetime
   expires the routing object in route
   validation, SHOULD be re-tested for validity.

   The validation lifetime for a potentially confusing mismatch ROA is controlled by the Valid times
   specified in the interpretation
   scope between End Entity (EE) Certificate used to sign the ROA ROA,
   and the BOA, where the ROAs scope was limited
   to set valid times of prefixes described those certificates in the ROA, while certification path
   used to validate the BOA's scope
   included all possible more specifics EE Certificate.  A ROA validation "expires" at
   the Validity To field of the prefixes listed in signing EE certificate, or at such a
   time when there is no certification path that can validate the
   BOA, and ROA.
   A ROA issuer may prematurely invalidate a ROA by revoking the ability EE
   certificate that was used to reconstruct sign the semantic equivalent ROA.

6.  Security Considerations

   ROA issuers should be aware of a BOA
   through the use of validation implication in issuing
   a ROA, in that a ROA implicitly invalidates all route objects that used
   have more specific prefixes with a restricted-use prefix length greater than
   maxLength, and all originating AS's other than the AS as its asID.
   Accordingly, listed in the
   collection of ROAs for this draft has been revised to remove all references prefix.

   A conservative operational practice would be to ensure the use issuing of an explicit denial object and uses
   ROAs for all more specific prefixes with distinct origination AS's
   prior to the implicit semantics issuing of denial ROAs for larger encompassing address blocks,
   in a ROA object.

   There appears order to be no WG interest in consideration avoid inadvertent invalidation of validation in
   a "linked" model, where valid route objects
   during ROA generation.

   ROA issuers should also be aware that if they generate a ROA is bound to for one
   origin AS, then if the prefix holder authorises multiple AS's to
   originate route object that objects it is
   intended to validate.  Accordingly this section of the text has also
   been dropped from this version. necessary for a ROA be generated for
   every such authorized AS.

7.  IANA Considerations

   [There are no IANA Considerations.]

8.  References

8.1.  Normative References

   [I-D.ietf-sidr-arch]
              Lepinski, M. and S. Kent, "An Infrastructure to Support
              Secure Internet Routing", draft-ietf-sidr-arch (work in
              progress), July October 2009.

   [I-D.ietf-sidr-roa-format]
              Lepinski, M., Kent, S., and D. Kong, "An Infrastructure to
              Support Secure Internet Routing",
              draft-ietf-sidr-roa-format (work in progress), July
              October 2009.

   [RFC3779]  Lynn, C., Kent, S., and K. Seo, "X.509 Extensions for IP
              Addresses and AS Identifiers", RFC 3779, June 2004.

   [RFC4271]  Rekhter, Y., Li, T., and S. Hares, "A Border Gateway
              Protocol 4 (BGP-4)", RFC 4271, January 2006.

   [RFC5280]  Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
              Housley, R., and W. Polk, "Internet X.509 Public Key
              Infrastructure Certificate and Certificate Revocation List
              (CRL) Profile", RFC 5280, May 2008.

8.2.  Informative References

   [IANA.AS-Registry]
              IANA, "IANA Autonomous System Number Registry",
              August 2009.
              March 2010.

Authors' Addresses

   Geoff Huston
   Asia Pacific Network Information Centre

   Email: gih@apnic.net
   George Michaelson
   Asia Pacific Network Information Centre

   Email: ggm@apnic.net