Source Address Validation Using BGP UPDATEs, ASPA, and ROA (BAR-SAV)
draft-ietf-sidrops-bar-sav-03
| Document | Type | Active Internet-Draft (sidrops WG) | |
|---|---|---|---|
| Authors | Kotikalapudi Sriram , Igor Lubashev , Doug Montgomery | ||
| Last updated | 2024-03-04 | ||
| Replaces | draft-sriram-sidrops-bar-sav | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Intended RFC status | (None) | ||
| Formats | |||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | WG Document | |
| Document shepherd | Keyur Patel | ||
| IESG | IESG state | I-D Exists | |
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | keyur@arrcus.com |
draft-ietf-sidrops-bar-sav-03
Internet Engineering Task Force (IETF) K. Sriram
Internet-Draft USA NIST
Updates: 8704 (if approved) I. Lubashev
Intended status: Best Current Practice Akamai
Expires: 5 September 2024 D. Montgomery
USA NIST
4 March 2024
Source Address Validation Using BGP UPDATEs, ASPA, and ROA (BAR-SAV)
draft-ietf-sidrops-bar-sav-03
Abstract
Designing an efficient source address validation (SAV) filter
requires minimizing false positives (i.e., avoiding blocking
legitimate traffic) while maintaining directionality (see RFC8704).
This document advances the technology for SAV filter design through a
method that makes use of BGP UPDATE messages, Autonomous System
Provider Authorization (ASPA), and Route Origin Authorization (ROA).
The proposed method's name is abbreviated as BAR-SAV. BAR-SAV can be
used by network operators to derive more robust SAV filters and thus
improve network resilience. This document updates RFC8704.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
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Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 5 September 2024.
Copyright Notice
Copyright (c) 2024 IETF Trust and the persons identified as the
document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 4
2. Same Procedure Applies to Customers and Lateral Peers . . . . 4
3. SAV Using ASPA and ROA (Procedure X) . . . . . . . . . . . . 4
4. SAV using BGP UPDATE Messages, ASPA, and ROA (BAR-SAV) . . . 5
5. Operational Recommendations . . . . . . . . . . . . . . . . . 7
5.1. Considerations for the CDN and DSR Scenario . . . . . . . 7
6. Operations and Management Considerations . . . . . . . . . . 9
6.1. Applicability of ASPA and ROA . . . . . . . . . . . . . . 9
6.2. BAR-SAV and Routing Policy . . . . . . . . . . . . . . . 10
6.3. Where to Deploy BAR-SAV . . . . . . . . . . . . . . . . . 10
6.4. Automation is the Key . . . . . . . . . . . . . . . . . . 10
6.5. Implementation Guidelines . . . . . . . . . . . . . . . . 11
6.5.1. Management of Local RPKI Repository Caches . . . . . 11
7. Provider Interfaces . . . . . . . . . . . . . . . . . . . . . 11
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
9. Security Considerations . . . . . . . . . . . . . . . . . . . 12
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 12
10.1. Normative References . . . . . . . . . . . . . . . . . . 12
10.2. Informative References . . . . . . . . . . . . . . . . . 13
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15
1. Introduction
Spoofed source addresses are often used in Denial of Service (DoS)
and Distributed DoS (DDoS) attacks. Source address validation (SAV)
filtering is used to drop packets with spoofed source addresses (see
BCP 84 [RFC3704] [RFC8704]). A detailed review of unicast Reverse
Path Forwarding (uRPF) techniques for SAV is provided in [RFC8704]).
Also, [RFC8704] describes enhanced feasible-path uRPF (EFP-uRPF)
methods that aim to minimize false positives (i.e., avoid blocking
legitimate traffic) while maintaining directionality (see definitions
in [RFC3704]).
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New technology for securing the Border Gateway Protocol (BGP)
[RFC4271] using Resource Public Key Infrastructure (RPKI) [RFC6480]
is seeing increasing adoption. Two of the currently existing or
proposed types of signed objects in the RPKI can be leveraged for a
more accurate SAV filter design as well. These are the Route Origin
Authorization (ROA) and the Autonomous System Provider Authorizations
(ASPA) objects. A ROA is a cryptographically signed attestation by
an IP address-resource holder listing their prefixes that are
authorized to be originated in BGP by a specific autonomous system
(AS) [RFC6482]. ROAs are currently used for RPKI-based Route Origin
Validation (RPKI-ROV) [RFC6811] [RFC9319]. An ASPA is a
cryptographically signed attestation by an AS listing its transit
provider AS numbers (ASNs) [I-D.ietf-sidrops-aspa-profile]. The ASPA
data is designed to be used for a form of AS path validation that can
detect and mitigate route leaks [I-D.ietf-sidrops-aspa-verification]
[sriram1]. See [RFC7908] for the definition of route leaks.
This document advances the technology for SAV filter design using
methods that make use of ASPA, ROA, and/or BGP UPDATE data. A method
is presented in Section 3 that makes use of only ASPA and ROA data to
design the SAV filter. This method is for use in the future when the
adoption of ROA and ASPA is considered to be ubiquitous. However,
for use in the period before that, another method for SAV is
presented in Section 4 that makes complementary use of BGP UPDATE
messages along with ASPA and ROA data. Accordingly, the latter
method's name is abbreviated as BAR-SAV. It is hoped that just as
the adoption of ROAs is growing at present [Monitor], the adoption of
ASPA will also gain momentum in the near future. The BAR-SAV method
additionally incorporates a refined version of Algorithm A of the
EFP-uRPF technique (Section 3.1 of [RFC8704]). BAR-SAV can be used
by network operators to derive more robust SAV filters and thus
improve network resilience.
The focus of this document is on the design of ingress SAV allowlist
filters for an interface facing a customer or lateral peer AS. The
same procedure applies in both cases (Section 2).
Throughout this document, ROA and ASPA data mean the payload data in
cryptographically valid ROA and ASPA objects (see Section 4 in
[RFC6482] and Section 4 in [I-D.ietf-sidrops-aspa-profile]).
The reader is encouraged to be familiar with [RFC8704], [RFC6482],
[RFC6811], [I-D.ietf-sidrops-aspa-profile], and
[I-D.ietf-sidrops-aspa-verification].
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1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2. Same Procedure Applies to Customers and Lateral Peers
The same procedure applies for the construction of a permissible
ingress SAV filter for a customer or lateral peer interface, because
the data packets received from a customer or lateral peer should have
source addresses belonging only to the prefixes in the customer cone
(CC) of said customer or lateral peer. The focus, therefore, is only
on the CC of the neighbor in each case. Note that the CC includes
the AS belonging to the customer or lateral peer.
3. SAV Using ASPA and ROA (Procedure X)
The procedure (called Procedure X) described in this section is for
future scenarios when ASPA and ROA adoption is ubiquitous. In that
scenario, robust SAV filters can be generated from the RPKI
information (ASPA and ROA data) alone. The procedure is applicable
for ingress SAV filter design for customer and lateral peer
interfaces. An ISP may use Procedure X on a customer (or lateral
peer) interface if it expects full adoption of ROAs and ASPAs in the
CC of the neighbor.
A description of Procedure X (one that makes use of only ASPA and ROA
data):
* Step A: Compute the set of ASNs in the Customer's or Lateral
Peer's customer cone using ASPA data.
* Step B: Compute from ROA data the set of prefixes authorized to be
announced by the ASNs found in Step A. Keep only the unique
prefixes. This set is the permissible prefix list for SAV for the
interface in consideration.
A detailed description of Procedure X is as follows:
1. Let the Customer or Lateral Peer ASN be denoted as AS-k.
2. Let i = 1. Initialize: AS-set S(1) = {AS-k}.
3. Increment i to i+1.
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4. Create AS-set S(i) of all ASNs whose ASPA data declares at least
one ASN in AS-set S(i-1) as a Provider.
5. If AS-set S(i) is null, then set i_max = i - 1 and go to Step 6.
Else, go to Step 3.
6. Form the union of the sets, S(i), i = 1, 2, ..., i_max, and name
this union as AS-set A.
7. Select all ROAs in which the authorized origin ASN is equal to
any ASN in AS-set A. Form the union of the sets of prefixes
listed in the selected ROAs. Name this union set of prefixes as
P-set.
8. Apply P-set as the list of permissible prefixes for SAV.
4. SAV using BGP UPDATE Messages, ASPA, and ROA (BAR-SAV)
SAV using BGP UPDATE Messages, ASPA, ROA (BAR-SAV) as well as ACLs is
described in this section and is meant for the period when there is a
partial deployment of ROAs and ASPAs. To compensate for incomplete
RPKI information, BAR-SAV augments ASPA data with BGP UPDATE AS_PATH
data (and ASN ACLs) for discovering CC ASes, and it augments ROA data
with BGP UPDATE data (and Prefix ACLs) for discovering all prefixes
associated with ASes in the CC. The details of this procedure are
described below.
BAR-SAV additionally incorporates a refined version of Algorithm A of
EFP-uRPF (Section 3.1 of [RFC8704]). Algorithm A in [RFC8704] picked
only the originating ASes from AS_PATHs received on the customer or
lateral peer interface in consideration and included them for SAV
filter computation. The variant of Algorithm A in [RFC8704] used
here includes all ASes in the AS_PATHs for the SAV filter
computation. Unless there is a route leak [RFC7908], each AS is a
customer of the AS added next in AS_PATHs of BGP UPDATE messages
received from a customer or lateral peer. Further customer-provider
AS relations within the CC are discovered by examining all unique
ASes in the AS_PATHs in BGP UPDATEs received on all interfaces (from
transit providers, customers, lateral peers, and IBGP peers). This
is described in the step-by-step procedure later in this section.
Note that if a multi-homed AS is present in an above-mentioned
AS_PATH and did not originate any prefix in the CC in consideration
but originated a prefix into an overlapping neighboring CC, then the
AS and prefix will still be detected and included in the design of
the SAV filter. This improves the accuracy of the SAV filter in the
BAR-SAV method in comparison to Algorithm A in [RFC8704].
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One should not compute a customer cone by separately processing ASPA
data and AS_PATH data and then merging the two sets of ASes at the
end. Doing so is likely to miss ASes from the customer cone.
Instead, both ASPAs and AS_PATHs should be used to iteratively expand
the discovered customer cone. When new ASes are discovered, both
ASPA and AS_PATH data should be used to discover customers of those
ASes. This process is repeated for newly discovered customer ASes
until there are no new ASes to be found.
As a measure of security, validation of the AS_PATH data in Adj-RIBs-
In [RFC4271] SHOULD be performed using the procedures in
[I-D.ietf-sidrops-aspa-verification] and any Invalid AS_PATHs must be
excluded from inputs to the BAR-SAV procedure. This ensures that BGP
UPDATEs containing route leaks are not considered for BAR-SAV filter
design. Please see additional discussion about route leaks in
Section 9.
As a further measure of security, validation of BGP routes in Adj-
RIBs-In MUST be performed by applying RPKI-ROV [RFC6811] and any
Invalid routes must be excluded from inputs to the BAR-SAV procedure.
Please see additional discussion about prefix/route filtering in
Section 9.
A detailed description of the BAR-SAV procedure is as follows:
1. Let the Customer or Lateral Peer ASN be denoted as AS-k.
2. Let i = 1. Initialize: AS-set Z(1) = {AS-k}.
3. Extend AS-set Z(1) to include ASNs from any ASN ACL configured
for this interface.
4. Increment i to i+1.
5. Create AS-set A(i) of all ASNs whose ASPA data declares at least
one ASN in AS-set Z(i-1) as a Provider.
6. Create AS-set B(i) of all customer ASNs each of which is a
customer of at least one ASN in AS-set Z(i-1) according to
unique AS_PATHs in Adj-RIBs-In of all interfaces at the BGP
speaker computing the SAV filter.
7. Form the union of AS-sets A(i) and B(i) and call it AS-set C.
From AS-set C, remove any ASNs that are present in Z(j), for j=1
to j=(i-1). Call the resulting set Z(i).
8. If AS-set Z(i) is null, then set i_max = i - 1 and go to Step 9.
Else, go to Step 4.
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9. Form the union of the AS-sets, Z(i), i = 1, 2, ..., i_max, and
name this union as AS-set D.
10. Select all ROAs in which the authorized origin ASN is in AS-set
D. Form the union of the sets of prefixes listed in the
selected ROAs. Name this union set of prefixes as Prefix-set
P1.
11. Using the routes in Adj-RIBs-In of all interfaces, create a list
of all prefixes originated by any ASN in AS-set D. Name this
set of prefixes as Prefix-set P2.
12. Form the union of Prefix-set P1, Prefix-set P2, and any Prefix
ACL configured for this interface. Apply this union set as the
list of permissible prefixes for SAV.
5. Operational Recommendations
Network operators SHOULD implement the BAR-SAV method (Section 4) for
computing the permissible ingress prefix list for SAV on interfaces
facing customers and lateral peers. BAR-SAV offers immediate
incremental benefits to early adopters.
The operational recommendations provided in Section 3.2 of [RFC8704]
are applicable and helpful for BAR-SAV (Section 4). Since Procedure
X (Section 3) and the BAR-SAV procedure (Section 4) benefit from the
registration of ROAs, network operators are RECOMMENDED to register
ROAs and enable RPKI-ROV in their ASes. When ASPA registration
becomes available, network operators are also RECOMMENDED to register
ASPAs at that time.
The registration of ROAs and ASPAs helps with the detection and
inclusion of otherwise hidden prefixes in the permissible list for
SAV. As mentioned earlier, prefixes hidden in other SAV techniques
often arise from the use of multi-homing in conjunction with limited
propagation of prefixes in a given CC (for example, by attaching
NO_EXPORT to all prefixes announced from a customer AS to a transit
provider AS). In these situations, the registration of ASPAs and
ROAs helps improve the accuracy of SAV.
5.1. Considerations for the CDN and DSR Scenario
Direct Server Return (DSR) is a common asymmetric routing scenario
that is not supported by existing BCP-84 uRPF [RFC3704] and EFP-uRPF
[RFC8704] SAV methods. DSR is commonly used by Content Delivery
Networks (CDNs) that wish to use anycast service addresses but
deliver data from edge locations that do not announce anycast
addresses.
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For example, in Figure 1, the CDN announces an anycast prefix P3
(from AS3) from a well-connected location with CDN control
infrastructure. When a User from prefix P1 (AS1) establishes a
connection to the anycast address and requests an object, an Anycast
Server at the CDN may determine that the best location to serve the
object is an Edge Server in a location close to the User. The Edge
Server is reachable only via prefix P2 (AS2). The Anycast Server can
forward packets arriving from the User to the Edge Server (via IP-IP
tunneling or similar means), but the bulk data transmission would
need to happen directly from the Edge Server to the User with an
anycast source address (a P3 address).
+----------+ P3{AS5 AS3} +------------+
| AS4 |<---------------| AS5 |
+----------+ (P2P) +------------+
/\ /\ /\
/ \ \
P1{AS1}/ \P2{AS2} \P3{AS3}
(C2P)/ \(C2P) \(C2P)
/ \ \
+----------+ +----------+ +----------+
| AS1 (P1)| | AS2 (P2) | | AS3 (P3) |
+-----+----+ +----+-----+ +-----+----+
+ + +
User Edge Server (DSR) Anycast Server
Consider AS4 generating SAV list for interface to AS2:
CDN's ROAs: {P3, AS3}, {P3, AS2}, {P2, AS2}
AS2 should not/does not announce P3
With the SAV methods in this document,
AS4 correctly includes P2 and P3 in the SAV list
Figure 1: Illustration of how the solution functions for the CDN/
DSR scenario.
Existing SAV methods of [RFC3704] and EFP-uRPF [RFC8704] would not
allow AS4 to include P3 as a legitimate SA prefix on the interface to
AS2. However, if the CDN (owner of prefix P3) registers a ROA object
authorizing AS2 to originate P3, and AS4 uses an SAV procedure
specified in this document (Section 4), then AS4 will use that ROA
object to include P3 as a valid source prefix for the AS2 customer
interface. The CDN may never want to announce a route to P3 from
AS2, but the existence of this ROA would result in the construction
of an SAV filter that would permit AS2 to send data packets with
source addresses belonging to P3.
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The CDN example above is just one DSR scenario. There are other
cloud-based DSR scenarios that include low-latency gaming, mobile
roaming, corporate networks of global enterprises, and others.
Recommendation: In a DSR scenario, a network operator MUST register
ROAs that bind the edge server ASes with the anycast service prefix.
This is in addition to registering a ROA authorizing the anycast
server AS to announce the anycast prefix.
6. Operations and Management Considerations
This section highlights some important operations and management
considerations and was motivated in part to address the comments
received from the SIDROPS working group members.
6.1. Applicability of ASPA and ROA
A transit provider is a network that (a) offers its customers
outbound (customer to Internet) data traffic connectivity and/or (b)
further propagates in all directions (towards providers, lateral
peers, and other customers) any BGP Updates that the customer may
send [I-D.ietf-sidrops-aspa-profile]. In the latter case, it also
provides transport for inbound data traffic. In all cases, the
customer AS SHOULD follow the specification in
[I-D.ietf-sidrops-aspa-profile] and include the transit provider AS
in its ASPA. Registering an ASPA prevents forged-origin hijacks for
the customer AS and its prefixes, prevents route leaks involving the
customer AS, and facilitates BAR-SAV.
If a prefix is used for source addresses for hosts attached at an AS
but not announced in BGP from that AS (e.g., the DSR scenario in
Section 5.1), a ROA MUST be registered binding the prefix and the AS.
This ROA registration assists in preventing hijacking of the prefix
and helps facilitate BAR-SAV. The risk of this ROA registration
enabling a forged-origin prefix hijack for the prefix is minimal
since the ASPA-based path verification
[I-D.ietf-sidrops-aspa-verification] prevents forged-origin attacks.
It may be noted that a similar usage of ROA is made in the context of
DDoS mitigation (see Section 5.1 in [RFC9319]), where hypothetically
the prefix may never need to be originated by the AS of the DDoS
mitigation provider.
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6.2. BAR-SAV and Routing Policy
BAR-SAV identifies all ASes in a customer's (or lateral peer's)
customer cone (CC), and then it discovers all prefixes that could
plausibly be used as source addresses in data traffic originated from
the ASes in the CC. If ASPA and ROA have been adopted by all ASes
and prefix owners, respectively, in the CC of interest, then the list
of plausible source address prefixes will be complete with no
improper block (i.e., traffic with legitimate source addresses is not
blocked). Further, deploying BAR-SAV by all ASes within the CC
ensures no improper permit (i.e., traffic with spoofed source address
is not admitted). Note that routing policies of ASes may be such
that some of the discovered prefixes may never be used as source
addresses on a given customer interface of interest, but this does
not impact BAR-SAV's accuracy.
6.3. Where to Deploy BAR-SAV
The discussion in Section 3.6.1 of [RFC8704] of the Forwarding
Information Base (FIB) size estimates and the networks where SAV
would be most effective are applicable to BAR-SAV as well. Smaller
ISPs (and possibly some midsize and regional ISPs) are expected to
implement the BAR-SAV method, since SAV in general is most effective
closer to the edges of the Internet. For such networks, the
conservatively estimated SAV filter list size is only a small
fraction of the anticipated FIB memory size (see details in
Section 3.6.1 of [RFC8704]).
6.4. Automation is the Key
SAV done manually, e.g., using ACLs, usually does not get much
adoption because of operational costs, susceptibility to human
errors, and tendency of SAV filters to get out of date due to the
need for any changes by customers or peers to be coordinated with
multiple parties (providers and peers). Automated uRPF technique,
such as BAR-SAV, however, allow for easy, accurate, and cost
effective deployments. The BAR-SAV method makes it possible to
automate the construction of SAV filter lists aiming for no improper
block and a minimal probability of improper permit of data traffic.
As ASPA adoption picks up alongside the ongoing ROA adoption, BAR-
SAV's accuracy of discovering all possible source addresses
(prefixes) for the customer cone of interest improves even further in
complex scenarios.
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6.5. Implementation Guidelines
When a SAV filter is used to police data traffic, and an incomplete
SAV filter list could cause legitimate traffic to be blocked, the use
of robust implementation practices for RPKI data retrieval and cache
management practices become paramount. Some of such recommended
practices are discussed in this section.
6.5.1. Management of Local RPKI Repository Caches
RPKI infrastructure does not guarantee continuous availability of
RPKI repositories. Local caches of RPKI signed objects, manifest
files (MFTs), and certificate revocation lists (CRLs) are already
maintained for managing ROA objects and router certificates
[RFC8210]. That is being extended to ASPA objects as well
[I-D.ietf-sidrops-8210bis]. The cache refresh frequency currently
used for RPKI data should be sufficient for BAR-SAV purposes as well.
If an RPKI repository publication point is unavailable, or there is
any other failure in fetching its objects, the latest cached version
of the objects associated with the repository MUST continue to be
used, as described in [RFC9286].
If the local cache of some repository objects required for BAR-SAV
computation is unavailable (for example, due to a filesystem failure)
and/or the RPKI data cannot be fetched from the repository
publication point, the SAV system SHOULD "fail open" and downgrade
the SAV function on a given interface to "loose uRPF" described in
[RFC3704] and [RFC8704]. This downgrade is better than suspending
SAV entirely since at least source addresses in unallocated and bogon
space are rejected.
7. Provider Interfaces
For most networks, "loose uRPF" SAV mode described in [RFC3704] and
[RFC8704] is the current best practice for provider interfaces to
ensure no improper block. It may be possible to use BGP UPDATE as
well as RPKI ROA and ASPA data to compute a list of prefixes that
originate exclusively within the customer cone and should only be
received by the AS on customer interfaces. A set of such prefixes
can be used in conjuction with "loose uRPF" SAV mode as a blocklist
on provider interfaces.
8. IANA Considerations
This document includes no request to IANA.
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9. Security Considerations
The security considerations described in [RFC8704], [RFC6811],
[I-D.ietf-sidrops-aspa-profile], and
[I-D.ietf-sidrops-aspa-verification] also apply to this document.
The security and robustness of BAR-SAV are strengthened by supporting
mechanisms for detecting and dropping BGP routes that are
misoriginations or leaks. Section 4 stated the requirement of
validating BGP route origins using RPKI-ROV [RFC6811]. It further
helps if route origin validation using trusted IRR route objects and
prefix filtering are also deployed (see [RFC7454] [NIST-800-189]).
It is also advised that one or more of the available methods to
prevent, detect, and mitigate route leaks are deployed (e.g.,
[RFC9234] [I-D.ietf-grow-route-leak-detection-mitigation]
[I-D.ietf-sidrops-aspa-verification] [sriram1]).
10. References
10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC3704] Baker, F. and P. Savola, "Ingress Filtering for Multihomed
Networks", BCP 84, RFC 3704, DOI 10.17487/RFC3704, March
2004, <https://www.rfc-editor.org/info/rfc3704>.
[RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
Border Gateway Protocol 4 (BGP-4)", RFC 4271,
DOI 10.17487/RFC4271, January 2006,
<https://www.rfc-editor.org/info/rfc4271>.
[RFC6482] Lepinski, M., Kent, S., and D. Kong, "A Profile for Route
Origin Authorizations (ROAs)", RFC 6482,
DOI 10.17487/RFC6482, February 2012,
<https://www.rfc-editor.org/info/rfc6482>.
[RFC6811] Mohapatra, P., Scudder, J., Ward, D., Bush, R., and R.
Austein, "BGP Prefix Origin Validation", RFC 6811,
DOI 10.17487/RFC6811, January 2013,
<https://www.rfc-editor.org/info/rfc6811>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
Sriram, et al. Expires 5 September 2024 [Page 12]
Internet-Draft BAR-SAV March 2024
[RFC8704] Sriram, K., Montgomery, D., and J. Haas, "Enhanced
Feasible-Path Unicast Reverse Path Forwarding", BCP 84,
RFC 8704, DOI 10.17487/RFC8704, February 2020,
<https://www.rfc-editor.org/info/rfc8704>.
10.2. Informative References
[RFC6480] Lepinski, M. and S. Kent, "An Infrastructure to Support
Secure Internet Routing", RFC 6480, DOI 10.17487/RFC6480,
February 2012, <https://www.rfc-editor.org/info/rfc6480>.
[RFC7454] Durand, J., Pepelnjak, I., and G. Doering, "BGP Operations
and Security", BCP 194, RFC 7454, DOI 10.17487/RFC7454,
February 2015, <https://www.rfc-editor.org/info/rfc7454>.
[RFC7908] Sriram, K., Montgomery, D., McPherson, D., Osterweil, E.,
and B. Dickson, "Problem Definition and Classification of
BGP Route Leaks", RFC 7908, DOI 10.17487/RFC7908, June
2016, <https://www.rfc-editor.org/info/rfc7908>.
[RFC8210] Bush, R. and R. Austein, "The Resource Public Key
Infrastructure (RPKI) to Router Protocol, Version 1",
RFC 8210, DOI 10.17487/RFC8210, September 2017,
<https://www.rfc-editor.org/info/rfc8210>.
[RFC9234] Azimov, A., Bogomazov, E., Bush, R., Patel, K., and K.
Sriram, "Route Leak Prevention and Detection Using Roles
in UPDATE and OPEN Messages", RFC 9234,
DOI 10.17487/RFC9234, May 2022,
<https://www.rfc-editor.org/info/rfc9234>.
[RFC9286] Austein, R., Huston, G., Kent, S., and M. Lepinski,
"Manifests for the Resource Public Key Infrastructure
(RPKI)", RFC 9286, DOI 10.17487/RFC9286, June 2022,
<https://www.rfc-editor.org/info/rfc9286>.
[RFC9319] Gilad, Y., Goldberg, S., Sriram, K., Snijders, J., and B.
Maddison, "The Use of maxLength in the Resource Public Key
Infrastructure (RPKI)", BCP 185, RFC 9319,
DOI 10.17487/RFC9319, October 2022,
<https://www.rfc-editor.org/info/rfc9319>.
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[I-D.ietf-sidrops-aspa-profile]
Azimov, A., Uskov, E., Bush, R., Snijders, J., Housley,
R., and B. Maddison, "A Profile for Autonomous System
Provider Authorization", Work in Progress, Internet-Draft,
draft-ietf-sidrops-aspa-profile-17, 7 November 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-sidrops-
aspa-profile-17>.
[I-D.ietf-sidrops-aspa-verification]
Azimov, A., Bogomazov, E., Bush, R., Patel, K., Snijders,
J., and K. Sriram, "BGP AS_PATH Verification Based on
Autonomous System Provider Authorization (ASPA) Objects",
Work in Progress, Internet-Draft, draft-ietf-sidrops-aspa-
verification-17, 29 February 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-sidrops-
aspa-verification-17>.
[I-D.ietf-grow-route-leak-detection-mitigation]
Sriram, K. and A. Azimov, "Methods for Detection and
Mitigation of BGP Route Leaks", Work in Progress,
Internet-Draft, draft-ietf-grow-route-leak-detection-
mitigation-10, 8 January 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-grow-
route-leak-detection-mitigation-10>.
[I-D.ietf-sidrops-8210bis]
Bush, R. and R. Austein, "The Resource Public Key
Infrastructure (RPKI) to Router Protocol, Version 2", Work
in Progress, Internet-Draft, draft-ietf-sidrops-8210bis-
11, 21 September 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-sidrops-
8210bis-11>.
[sriram1] Sriram, K. and J. Heitz, "On the Accuracy of Algorithms
for ASPA Based Route Leak Detection", IETF SIDROPS
Meeting, Proceedings of the IETF 110, March 2021,
<https://datatracker.ietf.org/meeting/110/materials/
slides-110-sidrops-sriram-aspa-alg-accuracy-01>.
[Monitor] "NIST RPKI Monitor", National Institute of Standards and
Technology, accessed June 2022,
<https://rpki-monitor.antd.nist.gov/>.
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[NIST-800-189]
Sriram, K. and D. Montgomery, "Resilient Interdomain
Traffic Exchange: BGP Security and DDoS Mitigation", NIST
Special Publication, NIST SP 800-189, December 2019,
<https://nvlpubs.nist.gov/nistpubs/SpecialPublications/
NIST.SP.800-189.pdf>.
Acknowledgements
The authors would like to thank Oliver Borchert, Job Snijders, Ben
Maddison, Geoff Huston, Dan Li, and many other members of the SIDROPS
and SAVNET working groups for comments and discussion.
Authors' Addresses
Kotikalapudi Sriram
USA National Institute of Standards and Technology
100 Bureau Drive
Gaithersburg, MD 20899
United States of America
Email: ksriram@nist.gov
Igor Lubashev
Akamai Technologies
145 Broadway
Cambridge, MA 02142
United States of America
Email: ilubashe@akamai.com
Doug Montgomery
USA National Institute of Standards and Technology
100 Bureau Drive
Gaithersburg, MD 20899
United States of America
Email: dougm@nist.gov
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