Secure Inter-Domain Routing T. Manderson
Internet-Draft ICANN
Intended status: Informational K. Sriram
Expires: June 25, 2011 US NIST
R. White
Cisco
December 22, 2010
Use Cases and interpretation of RPKI objects for issuers and relying
parties
draft-ietf-sidr-usecases-01
Abstract
This document provides use cases, directions, and interpretations for
organizations and relying parties when creating or encountering RPKI
object scenarios in the public RPKI in relation to the Internet
routing system.
Status of this Memo
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
1.2. Definitions . . . . . . . . . . . . . . . . . . . . . . . 4
1.3. Requirements Language . . . . . . . . . . . . . . . . . . 5
2. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1. General interpretation of RPKI object semantics . . . . . 6
3. Origination Use Cases . . . . . . . . . . . . . . . . . . . . 6
3.1. Single Announcement . . . . . . . . . . . . . . . . . . . 6
3.2. Aggregate with a More Specific . . . . . . . . . . . . . . 6
3.3. Aggregate with a More Specific from a Different ASN . . . 7
3.4. Sub-allocation to a Multi-homed Customer . . . . . . . . . 7
3.5. Restriction of a New Allocation . . . . . . . . . . . . . 8
3.6. Restriction of New ASN . . . . . . . . . . . . . . . . . . 8
3.7. Restriction of a Part of an Allocation . . . . . . . . . . 9
3.8. Restriction of Prefix Length . . . . . . . . . . . . . . . 9
3.9. Restriction of Sub-allocation Prefix Length . . . . . . . 10
3.10. Aggregation and Origination by an Upstream . . . . . . . . 10
3.11. Rogue Aggregation and Origination by an Upstream . . . . . 11
4. Adjacency Use Cases . . . . . . . . . . . . . . . . . . . . . 12
4.1. Multi-homed . . . . . . . . . . . . . . . . . . . . . . . 12
4.2. Restricting Peers . . . . . . . . . . . . . . . . . . . . 13
5. Partial Deployment Use Cases . . . . . . . . . . . . . . . . . 13
5.1. Parent does not do RPKI . . . . . . . . . . . . . . . . . 13
5.2. Only Some Children Participate in RPKI . . . . . . . . . . 14
5.3. Grandchild Does Not Participate in RPKI . . . . . . . . . 14
6. Transfer Use Cases . . . . . . . . . . . . . . . . . . . . . . 15
6.1. Transfer of in-use prefix and autonomous system number . . 15
6.2. Transfer of in-use prefix . . . . . . . . . . . . . . . . 15
6.3. Transfer of un-used prefix . . . . . . . . . . . . . . . . 15
7. Relying Party Use Cases . . . . . . . . . . . . . . . . . . . 16
7.1. ROA Expiry or receipt of a CRL covering a ROA . . . . . . 16
7.1.1. ROA of Parent Prefix is Revoked . . . . . . . . . . . 16
7.1.2. ROA of Prefix Revoked . . . . . . . . . . . . . . . . 16
7.1.3. ROA of Grandparent Prefix Revoked while that of
Parent Prefix Prevails . . . . . . . . . . . . . . . . 16
7.1.4. ROA of Prefix Revoked while that of Parent Prefix
Prevails . . . . . . . . . . . . . . . . . . . . . . . 17
7.1.5. Expiry of ROA of Parent Prefix . . . . . . . . . . . . 17
7.1.6. Expiry of ROA of Prefix . . . . . . . . . . . . . . . 17
7.1.7. Expiry of ROA of Grandparent Prefix while ROA of
Parent Prefix Prevails . . . . . . . . . . . . . . . . 17
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7.1.8. Expiry of ROA of Prefix while ROA of Parent Prefix
Prevails . . . . . . . . . . . . . . . . . . . . . . . 18
7.2. Prefix, Origin Validation use cases . . . . . . . . . . . 18
7.2.1. Covering ROA Prefix, maxLength Satisfied, and AS
Match . . . . . . . . . . . . . . . . . . . . . . . . 18
7.2.2. Covering ROA Prefix, maxLength Exceeded, and AS
Match . . . . . . . . . . . . . . . . . . . . . . . . 18
7.2.3. Covering ROA Prefix, maxLength Satisfied, and AS
Mismatch: . . . . . . . . . . . . . . . . . . . . . . 19
7.2.4. Covering ROA Prefix, maxLength Exceeded, and AS
Mismatch . . . . . . . . . . . . . . . . . . . . . . . 19
7.2.5. Covering ROA Prefix Not Found . . . . . . . . . . . . 19
7.2.6. Covering ROA Prefix Not Found but ROAs Exist for a
Covering Set of More Specifics . . . . . . . . . . . . 20
7.2.7. AS_SET in Update and Covering ROA Prefix Not Found . . 20
7.2.8. Singleton AS in AS_SET (in the Update), Covering
ROA Prefix, and AS Match . . . . . . . . . . . . . . . 20
7.2.9. Singleton AS in AS_SET (in the Update), Covering
ROA Prefix, and AS Mismatch . . . . . . . . . . . . . 21
7.2.10. Multiple ASs in AS_SET (in the Update) and
Covering ROA Prefix . . . . . . . . . . . . . . . . . 21
7.2.11. Update has an AS_SET as Origin and ROAs Exist for
a Covering Set of More Specifics . . . . . . . . . . . 21
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 22
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22
10. Security Considerations . . . . . . . . . . . . . . . . . . . 22
11. Normative References . . . . . . . . . . . . . . . . . . . . . 22
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 23
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1. Introduction
This document provides suggested use cases, directions, and
interpretations for organizations and relying parties when creating
or encountering RPKI object scenarios in the public RPKI in relation
to the Internet routing system.
1.1. Terminology
It is assumed that the reader is familiar with the terms and concepts
described in "Internet X.509 Public Key Infrastructure Certificate
and Certificate Revocation List (CRL) Profile" [RFC5280], "A Profile
for X.509 PKIX Resource Certificates" [I-D.ietf-sidr-res-certs]
"X.509 Extensions for IP Addresses and AS Identifiers" [RFC3779], "A
Profile for Route Origin Authorizations (ROAs)"
[I-D.ietf-sidr-roa-format], "Validation of Route Origination in BGP
using the Resource Certificate PKI and ROAs"
[I-D.ietf-sidr-roa-validation], and BGP Prefix Origin Validation"
[I-D.pmohapat-sidr-pfx-validate].
1.2. Definitions
The following definitions are in use in this document.
Autonomous System - A network under a single technical administration
that presents a consistent picture of what destinations are reachable
through it.
Autonomous System Number (ASN) - An officially registered number
representing an autonomous system.
Prefix - A network address and an integer that specifies the length
of a mask to be applied to the address to represent a set of
numerically adjacent addresses.
Route - A prefix and a sequence of one or more autonomous system
numbers.
Origin AS - The Autonomous System, designated by an ASN, which
originates a route. Seen as the "First" ASN in a route.
Specific route - A route that has a longer prefix than an aggregate.
Aggregate route - A more general route in the presence of a specific
route.
Covering Aggregate - A route that covers one or more specific routes.
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Multi-homed Autonomous System - An Autonomous System that is
connected, and announces routes, to two or more Autonomous Systems.
Multi-homed prefix or subnet - A prefix (i.e., subnet) that is
originated via two or more Autonomous Systems to which the subnet is
connected.
Resource - Internet (IP) addresses or Autonomous System Number.
Allocation - The set of resources provided to an entity or
organization for its use.
Sub-allocation - The set of a resources subordinate to an allocation
assigned to another entity or organization.
Transit Provider - An Autonomous System that carries traffic that
neither originates nor is the destination of that traffic.
Upstream - See "Transit Provider".
Child - A Sub-allocation that has resulted from an Allocation.
Parent - An allocation from which the subject prefix is a Child.
Grandchild - A Sub-allocation from one or more previous Sub-
allocations.
Grandparent - The allocation from which the prefix is a Grandchild.
Update prefix - The prefix seen in a routing update.
ROA prefix - The prefix described in a ROA.
Covering Prefix - The ROA Prefix is an exact match or a less specific
when compared to the update prefix.
No relevant ROA - No ROA exists that has a covering prefix for the
update prefix.
No other relevant ROA - No other ROA (besides any that is(are)
already cited) that has a covering prefix for the update prefix.
1.3. Requirements Language
The 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 RFC 2119.
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2. Overview
2.1. General interpretation of RPKI object semantics
It is important that in the interpretation of relying parties (RP),
or relying party routing software, that a 'make before break' stance
is applied. This means that a RP should implement a routing decision
process where a routing update ("route") is assumed to be intended
unless proven otherwise by the existence of a valid RPKI object. For
all of the cases in this document it is assumed that RPKI objects
validate (or otherwise) in accordance with [I-D.ietf-sidr-res-certs],
[I-D.ietf-sidr-arch], [I-D.ietf-sidr-roa-validation] unless otherwise
stated.
While many of the examples provided here illustrate organizations
using their own autonomous system numbers to originate routes, it
should be recognised that a prefix holder need not necessarily be the
holder of the autonomous system number used for the route
origination.
3. Origination Use Cases
This section deals with the various use cases where an organization
has Internet resources and will announce routes to the Internet. It
is based on operational observations of the existing routing system.
3.1. Single Announcement
An organization (Org A with ASN 64496) has been allocated the prefix
192.168.2.0/24. It wishes to announce the /24 prefix from ASN 64496
such that relying parties interpret the route as intended.
The desired announcement (and organization) would be:
+----------------------------------------------+
| Prefix | Origin AS | Organization |
+----------------------------------------------+
| 192.168.2.0/24 | AS64496 | Org A |
+----------------------------------------------+
The issuing party would create the following RPKI objects: TBC
3.2. Aggregate with a More Specific
An organization (Org A with ASN 64496) has been allocated the prefix
10.1.0.0/16. It wishes to announce the more specific prefix
10.1.0.0/20 from ASN 64496 as well as the aggregate route such that
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relying parties interpret the routes as intended.
The desired announcements (and organization) would be:
+----------------------------------------------+
| Prefix | Origin AS | Organization |
+----------------------------------------------+
| 10.1.0.0/16 | AS64496 | Org A |
| 10.1.0.0/20 | AS64496 | Org A |
+----------------------------------------------+
The issuing party would create the following RPKI objects: TBC
3.3. Aggregate with a More Specific from a Different ASN
An organization (Org A with ASN 64496 and ASN 64499) has been
allocated the prefix 10.1.0.0/16. It wishes to announce the more
specific prefix 10.1.0.0/20 from ASN 64499 as well as the aggregate
route from ASN 64496 such that relying parties interpret the routes
as intended.
The desired announcements (and organization) would be:
+---------------------------------------------+
| Prefix | Origin AS |Organization |
+---------------------------------------------+
| 10.1.0.0/16 | AS64496 | Org A |
| 10.1.0.0/20 | AS64499 | Org A |
+---------------------------------------------+
The issuing party would create the following RPKI objects: TBC
3.4. Sub-allocation to a Multi-homed Customer
An organization (Org A with ASN 64496) has been allocated the prefix
10.1.0.0/16, it wishes to announce the more specific prefix
10.1.0.0/20 from ASN 64496. It has further delegated 10.1.16.0/20 to
a customer (Org B with ASN 64511) who is multi-homed and will
originate the prefix route from ASN 64511. ASN 64496 will also
announce the aggregate route such that relying parties interpret the
routes as intended.
The desirable announcements (and organization) would be:
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+---------------------------------------------+
| Prefix | Origin AS |Organization |
+---------------------------------------------+
| 10.1.0.0/16 | AS64496 | Org A |
| 10.1.0.0/20 | AS64496 | Org A |
| 10.1.16.0/20 | AS64511 | Org B |
+---------------------------------------------+
The issuing parties would create the following RPKI objects: TBC
3.5. Restriction of a New Allocation
An organization has recently been allocated the prefix 10.1.0.0/16.
Its network deployment is not yet ready to announce the prefix and
wishes to restrict all possible announcements of 10.1.0.0/16 and more
specifics in routing using RPKI.
The following announcements would be considered undesirable:
+---------------------------------------------+
| Prefix | Origin AS |Organization |
+---------------------------------------------+
| 10.1.0.0/16 | ANY AS | ANY |
| 10.1.0.0/20 | ANY AS | ANY |
| 10.1.17.0/24 | ANY AS | ANY |
+---------------------------------------------+
The issuing party would create the following RPKI objects: TBC
3.6. Restriction of New ASN
An organization has recently been allocated an additional 4 byte ASN
65535. Its network deployment is not yet ready to use this ASN and
wishes to restrict all possible uses of ASN 65535 using RPKI.
The following announcements would be considered undesirable:
+---------------------------------------------+
| Prefix | Origin AS |Organization |
+---------------------------------------------+
| ANY | AS65535 | ANY |
+---------------------------------------------+
The issuing party would create the following RPKI objects: TBC
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3.7. Restriction of a Part of an Allocation
An organization (Org A with ASN 64496) has been allocated the prefix
10.1.0.0/16. Its network topology permits the announcement of
10.1.0.0/17 and the /16 aggregate. However it wishes to restrict any
possible announcement of 10.1.128.0/17 or more specifics of that /17
using RPKI.
The desired announcements would be:
+---------------------------------------------+
| Prefix | Origin AS |Organization |
+---------------------------------------------+
| 10.1.0.0/16 | AS64496 | Org A |
| 10.1.0.0/17 | AS64496 | Org A |
+---------------------------------------------+
The following announcements would be considered undesirable:
+---------------------------------------------+
| Prefix | Origin AS |Organization |
+---------------------------------------------+
| 10.1.128.0/17 | ANY AS | ANY |
| 10.1.128.0/24 | ANY AS | ANY |
+---------------------------------------------+
The issuing party would create the following RPKI objects: TBC
3.8. Restriction of Prefix Length
An organization (Org A with ASN 64496) has been allocated the prefix
10.1.0.0/16, it wishes to announce the aggregate and any or all more
specific prefixes up to and including a maximum length of /20, but
never any more specific than a /20.
Examples of the desired announcements (and organization) would be:
+---------------------------------------------+
| Prefix | Origin AS |Organization |
+---------------------------------------------+
| 10.1.0.0/16 | AS64496 | Org A |
| 10.1.0.0/17 | AS64496 | Org A |
| ... | AS64496 | Org A |
| 10.1.128.0/20 | AS64496 | Org A |
+---------------------------------------------+
The following announcements would be considered undesirable:
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+---------------------------------------------+
| Prefix | Origin AS |Organization |
+---------------------------------------------+
| 10.1.0.0/21 | ANY AS | ANY |
| 10.1.0.0/22 | ANY AS | ANY |
| ... | ANY AS | ANY |
| 10.1.128.0/24 | ANY AS | ANY |
+---------------------------------------------+
The issuing party would create the following RPKI objects: TBC
3.9. Restriction of Sub-allocation Prefix Length
An organization (Org A with ASN 64496) has been allocated the prefix
10.1.0.0/16, it sub-allocates several /20 prefixes to its multi-homed
customers Org B with ASN 65535, and Org C with ASN 64499. It wishes
to restrict those customers from advertising any corresponding routes
more specific than a /22.
The desired announcements would be:
+---------------------------------------------+
| Prefix | Origin AS |Organization |
+---------------------------------------------+
| 10.1.0.0/16 | AS64496 | Org A |
| 10.1.0.0/20 | AS65535 | Org B |
| 10.1.128.0/20 | AS64499 | Org C |
| 10.1.4.0/22 | AS65535 | Org B
+---------------------------------------------+
The following example announcements (and organization) would be
considered undesirable:
+---------------------------------------------+
| Prefix | Origin AS |Organization |
+---------------------------------------------+
| 10.1.0.0/24 | AS65535 | Org B |
| 10.1.128.0/24 | AS64499 | Org C |
| ..... | ... | ... |
| 10.1.0.0/23 | ANY AS | ANY |
+---------------------------------------------+
The issuing party would create the following RPKI objects: TBC
3.10. Aggregation and Origination by an Upstream
Consider four organizations with the following resources, which were
acquired independently from any transit provider. .
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+-------------------------------------------------+
| Organization | ASN | Prefix |
+-------------------------------------------------+
| Org A | AS64496 | 10.1.0.0/24 |
| Org B | AS65535 | 10.1.3.0/24 |
| Org C | AS64499 | 10.1.1.0/24 |
| Org D | AS64512 | 10.1.2.0/24 |
+-------------------------------------------------+
These organizations share a common upstream provider Transit A (ASN
64497) that originates an aggregate of these prefixes with the
permission of all four organizations.
The desired announcements (and organization) would be:
+----------------------------------------------+
| Prefix | Origin AS | Organization |
+----------------------------------------------+
| 10.1.0.0/24 | AS64496 | Org A |
| 10.1.3.0/24 | AS65535 | Org B |
| 10.1.1.0/24 | AS64499 | Org C |
| 10.1.2.0/24 | AS64512 | Org D |
| 10.1.0.0/22 | AS64497 | Transit A |
+----------------------------------------------+
The issuing parties would create the following RPKI objects: TBC
3.11. Rogue Aggregation and Origination by an Upstream
Consider four organizations with the following resources which were
acquired independently from any transit provider.
+-------------------------------------------------+
| Organization | ASN | Prefix |
+-------------------------------------------------+
| Org A | AS64496 | 10.1.0.0/24 |
| Org B | AS65535 | 10.1.3.0/24 |
| Org C | AS64499 | 10.1.1.0/24 |
| Org D | AS64512 | 10.1.2.0/24 |
+-------------------------------------------------+
These organizations share a common upstream provider Transit A (ASN
64497) that originates an aggregate of these prefixes where possible.
In this situation organization B (ASN 65535, 10.1.3.0/24) does not
wish for its prefix to be aggregated by the upstream
The desired announcements (and organization) would be:
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+----------------------------------------------+
| Prefix | Origin AS | Organization |
+----------------------------------------------+
| 10.1.0.0/24 | AS64496 | Org A |
| 10.1.3.0/24 | AS65535 | Org B |
| 10.1.1.0/24 | AS64499 | Org C |
| 10.1.2.0/24 | AS64512 | Org D |
| 10.1.0.0/23 | AS64497 | Transit A |
+----------------------------------------------+
The following announcement would be undesirable:
+----------------------------------------------+
| Prefix | Origin AS | Organization |
+----------------------------------------------+
| 10.1.0.0/22 | AS64497 | Transit A |
+----------------------------------------------+
The issuing parties would create the following RPKI objects: TBC
4. Adjacency Use Cases
Issues regarding validation of adjacency, or path validation, are
currently out of scope of the SIDR-WG charter. The use cases in this
section are listed here as a reminder that the work goes beyond
origination and at the stage when origination has been addressed by
the WG, a re-charter to encompass adjacency will allow consideration
of these use cases.
4.1. Multi-homed
An organization (Org A with ASN 64496) has been allocated the prefix
10.1.0.0/16. Its upstream transit providers are Transit A with ASN
65535 and Transit B with ASN 64499. The organization announces the
/16 aggregate. It permits that ASN 65535 and ASN 64499 may further
pass on the aggregate route to their peers or upstreams.
The following announcements and paths would be desired:
+---------------------------------------------------------+
| Prefix | Origin AS | Path |
+---------------------------------------------------------+
| 10.1.0.0/16 | AS64496 | AS64499 AS64496 |
| 10.1.0.0/16 | AS64496 | AS65535 AS64496 |
+---------------------------------------------------------+
The issuing parties would create the following RPKI objects: TBC
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4.2. Restricting Peers
An organization (Org A with ASN 64496) has been allocated the prefix
10.1.0.0/16. Its two upstreams are Transit X with ASN 65535 and
Transit Y with ASN 64499. The organization (ASN 64496) peers with a
third AS, Peer Z with ASN 64511. Org A announces the more specific
10.1.0.0/24 and the /16 aggregate. It wishes that only ASNs 65535
and 64499 may announce the aggregate and more specifics to their
upstreams. ASN 64511, the peer, may not further announce (pass on,
or leak) any routes for 10.1.0.0/16 and 10.1.0.0/24.
The following announcements and paths would be desired:
+---------------------------------------------------------+
| Prefix | Origin AS | Path |
+---------------------------------------------------------+
| 10.1.0.0/16 | AS64496 | AS64499 AS64496 |
| 10.1.0.0/24 | AS64496 | AS64499 AS64496 |
| 10.1.0.0/16 | AS64496 | AS65535 AS64496 |
| 10.1.0.0/24 | AS64496 | AS65535 AS64496 |
| 10.1.0.0/16 | AS64496 | Any_AS AS64499 AS64496 |
| 10.1.0.0/24 | AS64496 | Any_AS AS64499 AS64496 |
| 10.1.0.0/16 | AS64496 | Any_AS AS65535 AS64496 |
| 10.1.0.0/24 | AS64496 | Any_AS AS65535 AS64496 |
| 10.1.0.0/16 | AS64496 | AS64511 AS64496 |
| 10.1.0.0/24 | AS64496 | AS64511 AS64496 |
+---------------------------------------------------------+
The following announcements and paths would be considered
undesirable:
+---------------------------------------------------------+
| Prefix | Origin AS | Path |
+---------------------------------------------------------+
| 10.1.0.0/16 | AS64496 | Any_AS AS64511 AS64496 |
| 10.1.0.0/24 | AS64496 | Any_AS AS64511 AS64496 |
+---------------------------------------------------------+
The issuing parties would create the following RPKI objects: TBC
5. Partial Deployment Use Cases
5.1. Parent does not do RPKI
An organization (Org A with ASN 64511) is multi-homed has been
assigned the prefix 10.1.0.0/20 from its upstream (Transit X with ASN
64496). Org A wishes to announce the prefix 10.1.0.0/20 from ASN
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64511 to its other upstream(s). Org A also wishes to create RPKI
statements about the resource, however Transit X (ASN 64496) which
announces the aggregate 10.1.0.0/16 has not yet adopted RPKI.
The desired announcements (and organization with RPKI adoption) would
be:
+----------------------------------------------------+
| Prefix | Origin AS |Organization | RPKI |
+----------------------------------------------------+
| 10.1.0.0/20 | AS64511 | Org A | Yes |
| 10.1.0.0/16 | AS64496 | Transit X | No |
+----------------------------------------------------+
The issuing parties would create the following RPKI objects: TBC
5.2. Only Some Children Participate in RPKI
An organization (Org A with ASN 64496) has been allocated the prefix
10.1.0.0/16 and participates in RPKI, it wishes to announce the more
specific prefix 10.1.0.0/20 from ASN 64496. It has further delegated
10.1.16.0/20 and 10.1.32.0/20 to customers Org B with ASN 64511 and
and Org C with ASN 65535 (respectively) who are multi-homed. Org B
(ASN 64511) does not participate in RPKI. Org C (ASN 65535)
participates in RPKI.
The desired announcements (and organization with RPKI adoption) would
be:
+----------------------------------------------------+
| Prefix | Origin AS |Organization | RPKI |
+----------------------------------------------------+
| 10.1.0.0/16 | AS64496 | Org A | Yes |
| 10.1.0.0/20 | AS64496 | Org A | Yes |
| 10.1.16.0/20 | AS64511 | Org B | No |
| 10.1.32.0/20 | AS65535 | Org C | YES |
+----------------------------------------------------+
The issuing parties would create the following RPKI objects: TBC
5.3. Grandchild Does Not Participate in RPKI
Consider the previous example with an extension by where Org B, who
does not participate in RPKI, further allocates 10.1.17.0/24 to Org X
with ASN 64512. Org X does not participate in RPKI.
The desired announcements (and organization with RPKI adoption) would
be:
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+----------------------------------------------------+
| Prefix | Origin AS |Organization | RPKI |
+----------------------------------------------------+
| 10.1.0.0/16 | AS64496 | Org A | Yes |
| 10.1.0.0/20 | AS64496 | Org A | Yes |
| 10.1.16.0/20 | AS64511 | Org B | No |
| 10.1.32.0/20 | AS65535 | Org C | YES |
| 10.1.17.0/24 | AS64512 | Org X | No |
+----------------------------------------------------+
The issuing parties would create the following RPKI objects: TBC
6. Transfer Use Cases
6.1. Transfer of in-use prefix and autonomous system number
Organization A holds the resource 10.1.0.0/20 and it is currently in
use and originated from AS64496 with valid RPKI objects in place.
Organization B has acquired both the prefix and ASN and desires an
RPKI transfer on a particular date and time without adversely
affecting the operational use of the resource.
The following RPKI objects would be created/revoked: TBC
6.2. Transfer of in-use prefix
Organization A holds the resource 10.1.0.0/8 and it is currently in
use and originated from AS64496 with valid RPKI objects in place.
Organization B has acquired the address and desires an RPKI transfer
on a particular date and time. This prefix will be originated by
AS65535 as a result of this transfer.
The following RPKI objects would be created/revoked: TBC
6.3. Transfer of un-used prefix
Organization A holds the resource 10.1.0.0/8 and AS65535 (with RPKI
objects). Organization B has acquired an unused portion
(10.1.4.0/24) of the prefix and desires an RPKI transfer on a
particular date and time. Organization B will originate a route
10.1.4.0/24 from AS64496
The following RPKI objects would be created/revoked: TBC
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7. Relying Party Use Cases
7.1. ROA Expiry or receipt of a CRL covering a ROA
In the cases which follow, the terms "expired ROA" or "revoked ROA"
are shorthand, and describe the appropriate expiry or revocation of
the EE or Resource Certificates that causes a relying party to
consider the corresponding ROA to be viewed as expired or revoked.
7.1.1. ROA of Parent Prefix is Revoked
A certificate revocation list (CRL) is received which reveals that
the ROA containing the prefix 10.1.0.0/16; maxLength 24 with ASN64496
is revoked. Further, a prefix route exists in the Internet routing
system for 10.1.4.0/24 originated from ASN64496.
The Relying Party interpretation would be: TBC
7.1.2. ROA of Prefix Revoked
A CRL is received which reveals that the ROA containing the prefix
10.1.4.0/24; maxLength 24 with ASN64496 is revoked. Further, a
prefix route exists in the Internet routing system for 10.1.4.0/24
originated from ASN64496.
The Relying Party interpretation would be: TBC
A counter example: If there was simultaneously a valid ROA containing
the (less specific) prefix 10.1.0.0/20; maxLength 24 with ASN64496.
(see Section 7.1.4)
The Relying Party interpretation would be: TBC
7.1.3. ROA of Grandparent Prefix Revoked while that of Parent Prefix
Prevails
A CRL is received which reveals that the ROA containing the prefix
10.1.0.0/16; maxLength 24 with ASN64496 is revoked. Further, a
prefix route exists in the Internet routing system for 10.1.4.0/24
originated from ASN64496. Additionally, the current ROA list has a
valid ROA containing the prefix 10.1.0.0/20; maxLength 24 with
ASN64496.
The Relying Party interpretation would be: TBC
(Clarification: ROA for less specific grandparent prefix 10.1.0.0/16
was revoked or withdrawn)
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The Relying Party interpretation would be: TBC
7.1.4. ROA of Prefix Revoked while that of Parent Prefix Prevails
A CRL is received which reveals that the ROA containing the prefix
10.1.4.0/24; maxLength 24 with ASN64496 is revoked. Further, a
prefix route exists in the Internet routing system for 10.1.4.0/24
originated from ASN64496. Additionally, the current ROA list has a
valid ROA containing the prefix 10.1.0.0/20; maxLength 24 with
ASN64496.
The Relying Party interpretation would be: TBC
(Clarification: Perhaps the revocation of ROA for prefix 10.1.4.0/24
was initiated just to eliminate redundancy.)
7.1.5. Expiry of ROA of Parent Prefix
A scan of the ROA list reveals that the ROA containing the prefix
10.1.0.0/16; maxLength 24 with ASN64496 has expired. Further, a
prefix route exists in the Internet routing system for 10.1.4.0/24
originated from ASN64496.
The Relying Party interpretation would be: TBC
7.1.6. Expiry of ROA of Prefix
A scan of the ROA list reveals that the ROA containing the prefix
10.1.4.0/24; maxLength 24 with ASN64496 has expired. Further, a
prefix route exists in the Internet routing system for 10.1.4.0/24
originated from ASN64496.
The Relying Party interpretation would be: TBC
7.1.7. Expiry of ROA of Grandparent Prefix while ROA of Parent Prefix
Prevails
A scan of the ROA list reveals that the ROA containing the prefix
10.1.0.0/16; maxLength 24 with ASN64496 has expired. Further, a
prefix route exists in the Internet routing system for 10.1.4.0/24
originated from ASN64496. Additionally, the current ROA list has a
valid ROA containing the prefix 10.1.0.0/20; maxLength 24 with
ASN64496.
The Relying Party interpretation would be: TBC
(Clarification: ROA for less specific grandparent prefix 10.1.0.0/16
has expired.)
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7.1.8. Expiry of ROA of Prefix while ROA of Parent Prefix Prevails
A scan of the ROA list reveals that the ROA containing the prefix
10.1.4.0/24; maxLength 24 with ASN64496 has expired. Further, a
prefix route exists in the Internet routing system for 10.1.4.0/24
originated from ASN64496. Additionally, the current ROA list has a
valid ROA containing the prefix 10.1.0.0/20; maxLength 24 with
ASN64496.
The Relying Party interpretation would be: TBC
(Clarification: Perhaps the expiry of the ROA for prefix 10.1.4.0/24
was meant to eliminate redundancy.)
7.2. Prefix, Origin Validation use cases
These use cases try to systematically enumerate the situations a
relying party may encounter while receiving a BGP update and making
use of ROA information to interpret the validity of the prefix-origin
information in the update. We enumerate the situations or scenarios
but do not make a final recommendation on any RPKI interpretation.
For work on development of prefix-origin validation algorithms, see
[I-D.ietf-sidr-roa-validation] and [I-D.pmohapat-sidr-pfx-validate].
Also see [I-D.ietf-idr-deprecate-as-sets] for work-in-progress in the
IDR WG to deprecate AS_SETs in BGP updates (especially in the context
of RPKI-based validation).
7.2.1. Covering ROA Prefix, maxLength Satisfied, and AS Match
ROA: {10.1.0.0/16, maxLength = 20, AS64496}
Update has {10.1.0.0/17, Origin = AS64496}
Recommended RPKI prefix-origin validation interpretation: TBC
Comment: This is a straight forward prefix-origin validation use
case; it follows from the primary intention of creation of ROA by a
resource owner.
7.2.2. Covering ROA Prefix, maxLength Exceeded, and AS Match
ROA: {10.1.0.0/16, maxLength = 20, AS64496}
Update has {10.1.0.0/22, Origin = AS64496}
No other relevant ROA
Recommended RPKI prefix-origin validation interpretation: TBC
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Comment: In this case the maxLength specified in the ROA is exceeded
by the update prefix.
7.2.3. Covering ROA Prefix, maxLength Satisfied, and AS Mismatch:
ROA: {10.1.0.0/16, maxLength = 24, AS64496}
Update has {10.1.88.0/24, Origin = AS65535}
No other relevant ROA
Recommended RPKI prefix-origin validation interpretation: TBC
Comment: In this case an AS other than the one specified in the ROA
is originating an update. This may be a prefix or subprefix hijack
situation.
7.2.4. Covering ROA Prefix, maxLength Exceeded, and AS Mismatch
ROA: {10.1.0.0/16, maxLength = 22, AS64496}
Update has {10.1.88.0/24, Origin = AS65535}
No other relevant ROA
Recommended RPKI prefix-origin validation interpretation: TBC
Comment: In this case the maxLength specified in the ROA is exceeded
by the update prefix, and also an AS other than the one specified in
the ROA is originating the update. This may be a subprefix hijack
situation.
7.2.5. Covering ROA Prefix Not Found
Update has {240.1.1.0/24, Origin = AS65535}
No relevant ROA
Recommended RPKI prefix-origin validation interpretation: TBC
Comment: In this case there is no relevant ROA that has a covering
prefix for the update prefix. It could be a case of prefix or
subprefix hijack situation, but this announcement does not contradict
any existing ROA. During partial deployment, there would be some
legitimate prefix-origin announcements for which ROAs may not have
been issued yet.
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7.2.6. Covering ROA Prefix Not Found but ROAs Exist for a Covering Set
of More Specifics
ROA: {10.1.0.0/18, maxLength = 20, AS64496}
ROA: {10.1.64.0/18, maxLength = 20, AS64496}
ROA: {10.1.128.0/18, maxLength = 20, AS64496}
ROA: {10.1.192.0/18, maxLength = 20, AS64496}
Update has {10.1.0.0/16, Origin = AS64496}
No relevant ROA
Recommended RPKI prefix-origin validation interpretation: TBC
Comment: In this case the update prefix is an aggregate, and it turns
out that there exit ROAs for more specifics which, if combined, can
help support validation of the announced prefix-origin pair. But it
is very hard in general to breakup an announced prefix into
constituent more specifics and check for ROA coverage for those more
specifics.
7.2.7. AS_SET in Update and Covering ROA Prefix Not Found
Update has {10.1.0.0/16, Origin = [AS64496, AS64497, AS64498,
AS64497]}
No relevant ROA
Recommended RPKI prefix-origin validation interpretation: TBC
Comment: An extremely small percentage (~0.1%) of eBGP updates are
seen to have an AS_SET in them as origin; this is known as proxy
aggregation. In this case, update with the AS_SET does not conflict
with any ROA.
7.2.8. Singleton AS in AS_SET (in the Update), Covering ROA Prefix, and
AS Match
Update has {10.1.0.0/24, Origin = [AS64496]} (Note: AS_SET with
singleton AS appears in origin AS position.)
ROA: {10.1.0.0/22, maxLength = 24, AS64496}
Recommended RPKI prefix-origin validation interpretation: TBC
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Comment: In the spirit of [I-D.ietf-idr-deprecate-as-sets], possibly
any update with an AS_SET in it should not be considered valid (by
ROA-based validation). But does a scenario as described in the
example here need be treated differently?
7.2.9. Singleton AS in AS_SET (in the Update), Covering ROA Prefix, and
AS Mismatch
Update has {10.1.0.0/24, Origin = [AS64496]}
(Note: AS_SET with singleton AS appears in origin AS position.)
ROA: {10.1.0.0/22, maxLength = 24, AS65535} No other relevant ROA.
Recommended RPKI prefix-origin validation interpretation: TBC
Comment: In this case, update with the AS_SET does conflict with a
ROA and there is no other relevant ROA.
7.2.10. Multiple ASs in AS_SET (in the Update) and Covering ROA Prefix
Update has {10.1.0.0/22, Origin = [AS64496, AS64497, AS64498,
AS64497]}
ROA: {10.1.0.0/22, maxLength = 24, AS65535} No other relevant ROA.
Recommended RPKI prefix-origin validation interpretation: TBC
Comment: In this case, update with the AS_SET conflicts with a ROA
and there is no other relevant ROA.
7.2.11. Update has an AS_SET as Origin and ROAs Exist for a Covering
Set of More Specifics
ROA: {10.1.0.0/18, maxLength = 20, AS64496} ROA: {10.1.64.0/18,
maxLength = 20, AS64497} ROA: {10.1.128.0/18, maxLength = 20,
AS64498} ROA: {10.1.192.0/18, maxLength = 20, AS64499}
Update has {10.1.0.0/16, Origin = [AS64496, AS64497, AS64498,
AS64497]}
No (directly) relevant ROA
Recommended RPKI prefix-origin validation interpretation: TBC
Comment: In this case the aggregate of the prefixes in the ROAs is a
covering prefix for the update prefix. The ASs in each of the
contributing ROAs together form a set that matches the AS_SET in the
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update. But it is very hard in general to breakup an announced
prefix into constituent more specifics and check for ROA coverage for
those more specifics. In any case, it may be noted once again that
in the spirit of [I-D.ietf-idr-deprecate-as-sets], possibly any
update with an AS_SET in it should not be considered valid (by ROA-
based validation).
8. Acknowledgements
The authors are indebted to both Sandy Murphy and Sam Weiler for
their guidance. Further, the authors would like to thank Curtis
Villamizar, Steve Kent, and Danny McPherson for their technical
insight and review.
9. IANA Considerations
This memo includes no request to IANA.
10. Security Considerations
This memo requires no security considerations
11. Normative References
[I-D.ietf-idr-deprecate-as-sets]
Kumari, W., "Deprecation of BGP AS_SET, AS_CONFED_SET.",
draft-ietf-idr-deprecate-as-sets-00 (work in progress),
November 2010.
[I-D.ietf-sidr-arch]
Lepinski, M. and S. Kent, "An Infrastructure to Support
Secure Internet Routing", draft-ietf-sidr-arch-11 (work in
progress), September 2010.
[I-D.ietf-sidr-res-certs]
Huston, G., Michaelson, G., and R. Loomans, "A Profile for
X.509 PKIX Resource Certificates",
draft-ietf-sidr-res-certs-21 (work in progress),
December 2010.
[I-D.ietf-sidr-roa-format]
Lepinski, M., Kent, S., and D. Kong, "A Profile for Route
Origin Authorizations (ROAs)",
draft-ietf-sidr-roa-format-09 (work in progress),
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Internet-Draft RPKI Use Case and interpretations December 2010
November 2010.
[I-D.ietf-sidr-roa-validation]
Huston, G. and G. Michaelson, "Validation of Route
Origination using the Resource Certificate PKI and ROAs",
draft-ietf-sidr-roa-validation-10 (work in progress),
November 2010.
[I-D.pmohapat-sidr-pfx-validate]
Mohapatra, P., Scudder, J., Ward, D., Bush, R., and R.
Austein, "BGP Prefix Origin Validation",
draft-pmohapat-sidr-pfx-validate-07 (work in progress),
April 2010.
[RFC3779] Lynn, C., Kent, S., and K. Seo, "X.509 Extensions for IP
Addresses and AS Identifiers", RFC 3779, June 2004.
[RFC3852] Housley, R., "Cryptographic Message Syntax (CMS)",
RFC 3852, July 2004.
[RFC4055] Schaad, J., Kaliski, B., and R. Housley, "Additional
Algorithms and Identifiers for RSA Cryptography for use in
the Internet X.509 Public Key Infrastructure Certificate
and Certificate Revocation List (CRL) Profile", RFC 4055,
June 2005.
[RFC4271] Rekhter, Y., Li, T., and S. Hares, "A Border Gateway
Protocol 4 (BGP-4)", RFC 4271, January 2006.
[RFC4893] Vohra, Q. and E. Chen, "BGP Support for Four-octet AS
Number Space", RFC 4893, May 2007.
[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.
Authors' Addresses
Terry Manderson
ICANN
Email: terry.manderson@icann.org
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Kotikalapudi Sriram
US NIST
Email: ksriram@nist.gov
Russ White
Cisco
Email: russ@cisco.com
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