draft-ietf-idr-route-leak-detection-mitigation-00.txt   draft-ietf-idr-route-leak-detection-mitigation-01.txt 
IDR and SIDR K. Sriram IDR and SIDR K. Sriram
Internet-Draft D. Montgomery Internet-Draft D. Montgomery
Intended status: Standards Track US NIST Intended status: Standards Track US NIST
Expires: January 23, 2016 B. Dickson Expires: April 21, 2016 B. Dickson
Twitter, Inc.
July 22, 2015 K. Patel
Cisco
A. Robachevsky
Internet Society
October 19, 2015
Methods for Detection and Mitigation of BGP Route Leaks Methods for Detection and Mitigation of BGP Route Leaks
draft-ietf-idr-route-leak-detection-mitigation-00 draft-ietf-idr-route-leak-detection-mitigation-01
Abstract Abstract
In [I-D.ietf-grow-route-leak-problem-definition], the authors have In [I-D.ietf-grow-route-leak-problem-definition], the authors have
provided a definition of the route leak problem, and also enumerated provided a definition of the route leak problem, and also enumerated
several types of route leaks. In this document, we first examine several types of route leaks. In this document, we first examine
which of those route-leak types are detected and mitigated by the which of those route-leak types are detected and mitigated by the
existing origin validation (OV) [RFC 6811] and BGPSEC path validation existing origin validation (OV) [RFC 6811] and BGPSEC path validation
[I-D.ietf-sidr-bgpsec-protocol]. Where the current OV and BGPSEC [I-D.ietf-sidr-bgpsec-protocol]. Where the current OV and BGPSEC
protocols don't offer a solution, this document suggests an protocols don't offer a solution, this document suggests an
skipping to change at page 1, line 48 skipping to change at page 2, line 7
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 23, 2016. This Internet-Draft will expire on April 21, 2016.
Copyright Notice Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the Copyright (c) 2015 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Related Prior Work . . . . . . . . . . . . . . . . . . . . . 3 2. Related Prior Work . . . . . . . . . . . . . . . . . . . . . 3
3. Mechanisms for Detection and Mitigation of Route Leaks . . . 4 3. Mechanisms for Detection and Mitigation of Route Leaks . . . 4
3.1. Route Leak Protection (RLP) Field Encoding by Sending 3.1. Route Leak Protection (RLP) Field Encoding by Sending
Router . . . . . . . . . . . . . . . . . . . . . . . . . 6 Router . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.2. Recommended Actions at a Receiving Router for Detection 3.2. Recommended Actions at a Receiving Router for Detection
of Route Leaks . . . . . . . . . . . . . . . . . . . . . 8 of Route Leaks . . . . . . . . . . . . . . . . . . . . . 8
3.2.1. Recommended Actions at a Receiving Router when the 3.3. Possible Actions at a Receiving Router for Mitigation . . 9
Sender is a Customer . . . . . . . . . . . . . . . . 8 4. Stopgap Solution when Only Origin Validation is Deployed . . 9
3.2.2. Recommended Actions at a Receiving Router when the 5. Design Rationale and Discussion . . . . . . . . . . . . . . . 10
Sender is a Peer . . . . . . . . . . . . . . . . . . 9
3.3. Possible Actions at a Receiving Router for Mitigation . . 10
4. Stopgap Solution when Only Origin Validation is Deployed . . 10
5. Design Rationale and Discussion . . . . . . . . . . . . . . . 11
5.1. Is route-leak solution without BGPSEC a serious attack 5.1. Is route-leak solution without BGPSEC a serious attack
vector? . . . . . . . . . . . . . . . . . . . . . . . . . 11 vector? . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.2. Comparison with other methods, routing security BCP . . . 12 5.2. Are there cases when valley-free violations can be
6. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 considered legitimate? . . . . . . . . . . . . . . . . . 12
5.3. Comparison with other methods, routing security BCP . . . 12
6. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
7. Security Considerations . . . . . . . . . . . . . . . . . . . 13 7. Security Considerations . . . . . . . . . . . . . . . . . . . 13
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 14
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 14
10.1. Normative References . . . . . . . . . . . . . . . . . . 13 10.1. Normative References . . . . . . . . . . . . . . . . . . 14
10.2. Informative References . . . . . . . . . . . . . . . . . 13 10.2. Informative References . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18
1. Introduction 1. Introduction
In [I-D.ietf-grow-route-leak-problem-definition], the authors have In [I-D.ietf-grow-route-leak-problem-definition], the authors have
provided a definition of the route leak problem, and also enumerated provided a definition of the route leak problem, and also enumerated
several types of route leaks. In this document, we first examine several types of route leaks. In this document, we first examine
which of those route-leak types are detected and mitigated by the which of those route-leak types are detected and mitigated by the
existing Origin Validation (OV) [RFC6811] and BGPSEC path validation existing Origin Validation (OV) [RFC6811] and BGPSEC path validation
[I-D.ietf-sidr-bgpsec-protocol]. For the rest of this document, we [I-D.ietf-sidr-bgpsec-protocol]. For the rest of this document, we
use the term BGPSEC as synonymous with path validation. The BGPSEC use the term BGPSEC as synonymous with path validation. The BGPSEC
protocol provides cryptographic protection for some aspects of BGP protocol provides cryptographic protection for some aspects of BGP
update messages. OV and BGPSEC together offer mechanisms to protect update messages. OV and BGPSEC together offer mechanisms to protect
against mis-originations and hijacks of IP prefixes as well as man- against re-originations and hijacks of IP prefixes as well as man-in-
in-the-middle (MITM) AS path modifications. Route leaks (see the-middle (MITM) AS path modifications. Route leaks (see
[I-D.ietf-grow-route-leak-problem-definition] and references cited at [I-D.ietf-grow-route-leak-problem-definition] and references cited at
the back) are another type of vulnerability in the global BGP routing the back) are another type of vulnerability in the global BGP routing
system against which OV and BGPSEC so far offer only partial system against which OV and BGPSEC so far offer only partial
protection. protection.
For the types of route leaks enumerated in For the types of route leaks enumerated in
[I-D.ietf-grow-route-leak-problem-definition], where the current OV [I-D.ietf-grow-route-leak-problem-definition], where the current OV
and BGPSEC protocols don't offer a solution, this document suggests and BGPSEC protocols don't offer a solution, this document suggests
an enhancement that would extend the detection and mitigation an enhancement that would extend the detection and mitigation
capability of BGPSEC. The solution can be implemented in BGP without capability of BGPSEC. The solution can be implemented in BGP without
skipping to change at page 3, line 37 skipping to change at page 3, line 43
in recent years. The document also includes (in Section 4) a stopgap in recent years. The document also includes (in Section 4) a stopgap
method for detection and mitigation of route leaks for the phase when method for detection and mitigation of route leaks for the phase when
BGPSEC (path validation) is not yet deployed but only origin BGPSEC (path validation) is not yet deployed but only origin
validation is deployed. validation is deployed.
2. Related Prior Work 2. Related Prior Work
The basic idea and mechanism embodied in the proposed solution is The basic idea and mechanism embodied in the proposed solution is
based on setting an attribute in BGP route announcement to manage the based on setting an attribute in BGP route announcement to manage the
transmission/receipt of the announcement based on the type of transmission/receipt of the announcement based on the type of
neighbor (e.g. customer, provider, etc.). Documented prior work neighbor (e.g. customer, transit provider, etc.). Documented prior
related to said basic idea and mechanism dates back to at least the work related to said basic idea and mechanism dates back to at least
1980's. Some examples of prior work are: (1) Information flow rules the 1980's. Some examples of prior work are: (1) Information flow
described in [proceedings-sixth-ietf] (see pp. 195-196); (2) Link rules described in [proceedings-sixth-ietf] (see pp. 195-196); (2)
Type described in [RFC1105-obsolete] (see pp. 4-5); (3) Hierarchical Link Type described in [RFC1105-obsolete] (see pp. 4-5); (3)
Recording described in [draft-kunzinger-idrp-ISO10747-01] (see Hierarchical Recording described in
Section 6.3.1.12). The problem of route leaks and possible solution [draft-kunzinger-idrp-ISO10747-01] (see Section 6.3.1.12). The
mechanisms based on encoding peering-link type information (e.g. p2c, problem of route leaks and possible solution mechanisms based on
c2p, p2p, etc.) in BGPSEC updates and protecting the same under encoding peering-link type information, e.g. P2C (i.e. Transit-
BGPSEC path signatures have been discussed in IETF SIDR WG at least Provider to Customer), C2P (i.e. Customer to Transit-Provider), p2p
since 2011. Dickson developed the initial Internet draft of these (i.e. peer to peer) etc., in BGPSEC updates and protecting the same
mechanisms in a BGPSEC context; see under BGPSEC path signatures have been discussed in IETF SIDR WG at
least since 2011. Dickson developed the initial Internet draft of
these mechanisms in a BGPSEC context; see
[draft-dickson-sidr-route-leak-solns]. The draft expired in 2012. [draft-dickson-sidr-route-leak-solns]. The draft expired in 2012.
[draft-dickson-sidr-route-leak-solns] defined neighbor relationships [draft-dickson-sidr-route-leak-solns] defined neighbor relationships
on a per link basis, but in the current draft the relationship in on a per link basis, but in the current draft the relationship in
encoded per prefix, as prefixes with different business models are encoded per prefix, as routes for prefixes with different business
often sent over the same link. Also models are often sent over the same link. Also
[draft-dickson-sidr-route-leak-solns] proposed a second signature [draft-dickson-sidr-route-leak-solns] proposed a second signature
block for the link type encoding, separate from the path signature block for the link type encoding, separate from the path signature
block in BGPSEC. By contrast, in the current draft when BGPSEC-based block in BGPSEC. By contrast, in the current draft when BGPSEC-based
solution is considered, cryptographic protection is provided for solution is considered, cryptographic protection is provided for
Route Leak Protection (RLP) encoding using the same signature block Route Leak Protection (RLP) encoding using the same signature block
as that for path signatures (see Section 3.1). as that for path signatures (see Section 3.1).
3. Mechanisms for Detection and Mitigation of Route Leaks 3. Mechanisms for Detection and Mitigation of Route Leaks
Referring to the enumeration of route leaks discussed in Referring to the enumeration of route leaks discussed in
[I-D.ietf-grow-route-leak-problem-definition], Table 1 summarizes the [I-D.ietf-grow-route-leak-problem-definition], Table 1 summarizes the
route-leak detection capability offered by OV and BGPSEC for route-leak detection capability offered by OV and BGPSEC for
different types of route leaks. (Note: Prefix filtering is not different types of route leaks. (Note: Prefix filtering is not
considered here in this table. Please see Section 4.) considered here in this table. Please see Section 4.)
A detailed explanation of the contents of Table 1 is as follows. It A detailed explanation of the contents of Table 1 is as follows. It
is readily observed that route leaks of Types 1, 5, 6, and 7 are not is readily observed that route leaks of Types 1, 2, 3, and 4 are not
detected by OV or even by BGPSEC. Type 2 route leak involves detected by OV or even by BGPSEC. Type 5 route leak involves
changing a prefix to a subprefix (i.e. more specific); such a changing a prefix to a more specific; such a modified update will
modified update will fail BGPSEC checks. Clearly, Type 3 route leak fail BGPSEC checks. Clearly, Type 6 route leak involves re-
involves mis-origination or hijacking, and hence can be detected by origination or hijacking, and hence can be detected by OV. In the
OV. In the case of Type 3 route leak, there would be no existing case of Type 6 route leak, there would be no existing ROAs to
ROAs to validate a re-originated prefix or subprefix, but instead a validate a re-originated prefix or more specific, but instead a
covering ROA would normally exist with the legitimate AS, and hence covering ROA would normally exist with the legitimate AS, and hence
the update will be considered Invalid by OV. the update will be considered Invalid by OV.
+---------------------------------+---------------------------------+ +---------------------------------+---------------------------------+
| Type of Route Leak | Detection Coverage and Comments | | Type of Route Leak | Detection Coverage and Comments |
+---------------------------------+---------------------------------+ +---------------------------------+---------------------------------+
| Type 1: U-Turn with Full Prefix | Neither OV nor BGPSEC (in its | | Type 1: U-Shaped Turn with Full | Neither OV nor BGPSEC (in its |
| | current form) detects Type 1. | | Prefix | current form) detects Type 1. |
| ------------------------------- | ------------------------------- | | ------------------------------- | ------------------------------- |
| Type 2: U-Turn with More | In OV, the ROA maxLength may | | Type 2: Lateral ISP-ISP-ISP | Neither OV nor BGPSEC (in its |
| Specific Prefix | offer detection of Type 2 in | | Leak | current form) detects Type 2. |
| ------------------------------- | ------------------------------- |
| Type 3: Leak of Transit- | Neither OV nor BGPSEC (in its |
| Provider Prefixes to Peer | current form) detects Type 3. |
| ------------------------------- | ------------------------------- |
| Type 4: Leak of Peer Prefixes | Neither OV nor BGPSEC (in its |
| to Transit Provider | current form) detects Type 4. |
| ------------------------------- | ------------------------------- |
| Type 5: U-Shaped Turn with More | In OV, the ROA maxLength may |
| Specific Prefix | offer detection of Type 5 in |
| | some cases; BGPSEC (in its | | | some cases; BGPSEC (in its |
| | current form) always detects | | | current form) always detects |
| | Type 2. | | | Type 5. |
| ------------------------------- | ------------------------------- | | ------------------------------- | ------------------------------- |
| Type 3: Prefix Mis-Origination | OV by itself detects Type 3; | | Type 6: Prefix Re-Origination | OV by itself detects Type 6; |
| with Data Path to Legitimate | BGPSEC does not detect Type 3. | | with Data Path to Legitimate | BGPSEC does not detect Type 6. |
| Origin | | | Origin | |
| ------------------------------- | ------------------------------- | | ------------------------------- | ------------------------------- |
| Type 4: Leak of Internal | For internal prefixes never | | Type 7: Accidental Leak of | For internal prefixes never |
| Prefixes and Accidental | meant to be seen (i.e. routed) | | Internal Prefixes and More | meant to be seen (i.e. routed) |
| Deaggregation | on the Internet, OV helps | | Specifics | on the Internet, OV helps |
| | detect their leak; they might | | | detect their leak; they might |
| | either have no covering ROA or | | | either have no covering ROA or |
| | have an AS0-ROA to always | | | have an AS0-ROA to always |
| | filter them. In the case of | | | filter them. In the case of |
| | accidental deaggregation, OV | | | accidental leak of more |
| | may offer some detection due to | | | specifics, OV may offer some |
| | ROA maxLength. BGPSEC does not | | | detection due to ROA maxLength. |
| | catch Type 4. | | | BGPSEC does not catch Type 7. |
| ------------------------------- | ------------------------------- |
| Type 5: Lateral ISP-ISP-ISP | Neither OV nor BGPSEC (in its |
| Leak | current form) detects Type 5. |
| ------------------------------- | ------------------------------- |
| Type 6: Leak of Provider | Neither OV nor BGPSEC (in its |
| Prefixes to Peer | current form) detects Type 6. |
| ------------------------------- | ------------------------------- |
| Type 7: Leak of Peer Prefixes | Neither OV nor BGPSEC (in its |
| to Provider | current form) detects Type 7. |
+---------------------------------+---------------------------------+ +---------------------------------+---------------------------------+
Table 1: Examination of Route-Leak Detection Capability of Origin Table 1: Examination of Route-Leak Detection Capability of Origin
Validation and Current BGPSEC Path Validation Validation and Current BGPSEC Path Validation
In the case of Type 4 leaks involving internal prefixes that are not In the case of Type 7 leaks involving internal prefixes that are not
meant to be routed in the Internet, they are likely to be detected by meant to be routed in the Internet, they are likely to be detected by
OV. That is because such prefixes might either have no covering ROA OV. That is because such prefixes might either have no covering ROA
or have an AS0-ROA to always filter them. In the case of Type 4 or have an AS0-ROA to always filter them. In the case of Type 7
leaks that are due to accidental deaggregation, they may be detected leaks that are due to accidental leak of more specifics, they may be
due to violation of ROA maxLength. BGPSEC does not catch Type 4. detected due to violation of ROA maxLength. BGPSEC does not catch
However, route leaks of Type 4 are least problematic due to the Type 7. However, route leaks of Type 7 are least problematic due to
following reasons. In the case of accidental deaggregation, the the following reasons. In the case of leak of more specifics, the
offending AS is itself the legitimate destination of the leaked more- offending AS is itself the legitimate destination of the leaked more-
specific prefixes. Hence, in most cases of this type, the data specific prefixes. Hence, in most cases of this type, the data
traffic is neither misrouted not denied service. Also, leaked traffic is neither misrouted not denied service. Also, leaked
announcements of Type 4 are short-lived and typically withdrawn announcements of Type 7 are short-lived and typically withdrawn
quickly following the announcements. Further, the MaxPrefix limit quickly following the announcements. Further, the MaxPrefix limit
may kick-in in some receiving routers and that helps limit the may kick-in in some receiving routers and that helps limit the
propagation of sometimes large number of leaked routes of Type 4. propagation of sometimes large number of leaked routes of Type 7.
Realistically, BGPSEC may take a much longer time being deployed than Realistically, BGPSEC may take a much longer time being deployed than
OV. Hence solution proposals for route leaks should consider both OV. Hence solution proposals for route leaks should consider both
scenarios: (A) OV only (without BGPSEC) and (B) OV plus BGPSEC. scenarios: (A) OV only (without BGPSEC) and (B) OV plus BGPSEC.
Assuming an initial scenario A, and based on the above discussion and Assuming an initial scenario A, and based on the above discussion and
Table 1, it is evident that in our proposed solution method, we need Table 1, it is evident that in our proposed solution method, we need
to focus primarily on route leaks of Types 1, 2, 5, 6, and 7. In to focus primarily on route leaks of Types 1, 2, 3, 4, and 5. In
Section 3.1 and Section 3.2, we describe a simple addition to BGP Section 3.1 and Section 3.2, we describe a simple addition to BGP
that facilitates detection of route leaks of Types 1, 2, 5, 6, and 7. that facilitates detection of route leaks of Types 1, 2, 3, 4, and 5.
The simple addition involves a Route Leak Protection (RLP) field, The simple addition involves a Route Leak Protection (RLP) field,
which is carried in an optional transitive path attribute in BGP. which is carried in an optional transitive path attribute in BGP.
When BGPSEC is deployed, the RLP field will be accommodated in the When BGPSEC is deployed, the RLP field will be accommodated in the
existing Flags field (see [I-D.ietf-sidr-bgpsec-protocol]) which is existing Flags field (see [I-D.ietf-sidr-bgpsec-protocol]) which is
cryptographically protected under path signatures. cryptographically protected under path signatures.
3.1. Route Leak Protection (RLP) Field Encoding by Sending Router 3.1. Route Leak Protection (RLP) Field Encoding by Sending Router
The key principle is that, in the event of a route leak, a receiving The key principle is that, in the event of a route leak, a receiving
router in a provider AS (e.g. referring to Figure 1, ISP2 (AS2) router in a transit-provider AS (e.g. referring to Figure 1, ISP2
router) should be able to detect from the prefix-update that its (AS2) router) should be able to detect from the update message that
customer AS (e.g. AS3 in Figure 1) SHOULD NOT have forwarded the its customer AS (e.g. AS3 in Figure 1) SHOULD NOT have forwarded the
update (towards the provider AS). This means that at least one of update (towards the transit-provider AS). This means that at least
the ASes in the AS path of the update has indicated that it sent the one of the ASes in the AS path of the update has indicated that it
update to its customer or peer AS, but forbade any subsequent 'Up' sent the update to its customer or lateral (i.e. non-transit) peer,
forwarding (i.e. from a customer AS to its provider AS). For this but forbade any subsequent 'Up' forwarding (i.e. from a customer AS
purpose, a Route Leak Protection (RLP) field to be set by a sending to its transit-provider AS). For this purpose, a Route Leak
router is proposed to be used for each AS hop. Protection (RLP) field to be set by a sending router is proposed to
be used for each AS hop.
/\ /\ /\ /\
\ route-leak(P)/ \ route-leak(P)/
\ propagated / \ propagated /
\ / \ /
+------------+ peer +------------+ +------------+ peer +------------+
______| ISP1 (AS1) |----------->| ISP2 (AS2)|----------> ______| ISP1 (AS1) |----------->| ISP2 (AS2)|---------->
/ ------------+ prefix(P) +------------+ route-leak(P) / ------------+ prefix(P) +------------+ route-leak(P)
| prefix | \ update /\ \ propagated | prefix | \ update /\ \ propagated
\ (P) / \ / \ \ (P) / \ / \
skipping to change at page 7, line 30 skipping to change at page 7, line 30
+---------------+ +---------------+
Figure 1: Illustration of the basic notion of a route leak. Figure 1: Illustration of the basic notion of a route leak.
For the purpose of route leak detection and mitigation proposed in For the purpose of route leak detection and mitigation proposed in
this document, the RLP field value SHOULD be set to one of two values this document, the RLP field value SHOULD be set to one of two values
as follows: as follows:
o 00: This is the default value (i.e. "nothing specified"), o 00: This is the default value (i.e. "nothing specified"),
o 01: This is the 'Do not Propagate Up' indication; sender o 01: This is the 'Do not Propagate Up or Lateral' indication;
indicating that the prefix-update SHOULD NOT be forwarded 'Up' sender indicating that the route SHOULD NOT be forwarded 'Up'
towards a provider AS. towards a transit-provider AS or to a lateral (i.e. non-transit)
peer AS.
There are two different scenarios when a sending AS SHOULD set the The RLP indications SHOULD be set on a per prefix and per neighbor AS
'01' indication in a prefix-update: (1) when sending the prefix- basis. This is because updates for prefixes with different business
update to a customer AS, and (2) to let a peer AS know not to forward models are often sent over the same link between ASes.
the prefix-update 'Up' towards a provide AS. In essence, in both
scenarios, the intent of '01' indication is that any receiving AS
along the subsequent AS path SHOULD NOT forward the prefix-update
'Up' towards its (receiving AS's) provider AS.
One may argue for additional RLP indications: for example, '10' to There are two different scenarios when a sending AS SHOULD set the
specify 'Propagate to Customers Only', and possibly '11' to signal '01' indication in an update: (1) when sending the update to a
'Do Not Propagate' (i.e. NO_EXPORT). But in the interest of keeping customer AS, and (2) when sending the update to a lateral peer (i.e.
the methodology simple, the choice of two RLP field values as defined non-transit) AS. In essence, in both scenarios, the intent of '01'
above (00 - default, and 01 - 'Do not Propagate Up') is all that is indication is that the neighbor AS and any receiving AS along the
needed. This two-state specification in the RLP field can be shown subsequent AS path SHOULD NOT forward the update 'Up' towards its
to work for detection and mitigation of route leaks of Types 1, 2, 5, (receiving AS's) transit-provider AS or laterally towards its peer
6, and 7, which are the focus here (see Section 3.2 and Section 3.3). (i.e. non-transit) AS. When sending an update 'Up' to a transit-
provider AS, the RLP encoding should be set to the default value of
'00'. When a sending AS sets the RLP encoding to '00', it is
indicating to the receiving AS that the update can be propagated in
any direction (i.e. towards transit-provider, customer, or lateral
peer). This two-state specification in the RLP field can be shown to
work for detection and mitigation of route leaks of Types 1, 2, 3, 4,
and 5, which are the focus here (see Section 3.2 and Section 3.3).
The '10' and '11' values in the RLP field (assuming that two bits are
used to encode it) are currently unassigned, and reserved for
possible future use.
The proposed RLP encoding SHOULD be carried in BGP-4 [RFC4271] The proposed RLP encoding SHOULD be carried in BGP-4 [RFC4271]
updates in an optional transitive path attribute. In BGPSEC enabled updates in an optional transitive path attribute. In BGPSEC enabled
routers, the RLP encoding SHOULD be accommodated in the existing routers, the RLP encoding SHOULD be accommodated in the existing
Flags field in BGPSEC updates. The Flags field is part of the Flags field in BGPSEC updates. The Flags field is part of the
Secure_Path Segment in BPGSEC updates Secure_Path Segment in BPGSEC updates
[I-D.ietf-sidr-bgpsec-protocol]. It is one octet long, and one Flags [I-D.ietf-sidr-bgpsec-protocol]. It is one octet long, and one Flags
field is available for each AS hop, and currently only the first bit field is available for each AS hop, and currently only the first bit
is used in BGPSEC. So there are 7 bits that are currently unused in is used in BGPSEC. So there are 7 bits that are currently unused in
the Flags field. Two (or more if needed) of these bits can be the Flags field. Two (or more if needed) of these bits can be
designated for the RLP field. Since the BGPSEC protocol designated for the RLP field. Since the BGPSEC protocol
specification requires a sending AS to include the Flags field in the specification requires a sending AS to include the Flags field in the
data that are signed over, the RLP field for each hop (assuming it data that are signed over, the RLP field for each hop (assuming it
would be part of the Flags field) will be protected under the sending would be part of the Flags field) will be protected under the sending
AS's signature. AS's signature.
3.2. Recommended Actions at a Receiving Router for Detection of Route 3.2. Recommended Actions at a Receiving Router for Detection of Route
Leaks Leaks
The recommended receiver actions differ slightly depending on whether
the update is received from a customer or a peer. When detecting
route leaks of Type 1, 2, and 7, the receiving router is dealing with
a customer as the sender. When detecting route leaks of Type 5 and
6, the receiving router is dealing with a peer as the sender.
3.2.1. Recommended Actions at a Receiving Router when the Sender is a
Customer
We provide here an example set of receiver actions that work to We provide here an example set of receiver actions that work to
detect and mitigate route leaks of Types 1, 2, and 7. This example detect and mitigate route leaks of Types 1, 2, 3, 4, and 5. This
algorithm serves as a proof of concept. However, other receiver example algorithm serves as a proof of concept. However, other
algorithms or procedures can be designed (based on the same sender receiver algorithms or procedures can be designed (based on the same
specification as in Section 3.1) and may perform with greater sender specification as in Section 3.1) and may perform with greater
efficacy, and are by no means excluded. efficacy, and are by no means excluded.
A recommended receiver algorithm for detecting a route leak is as A recommended receiver algorithm for detecting a route leak is as
follows: follows:
A receiving router SHOULD mark an update as a Route-Leak if ALL of A receiving router SHOULD mark an update as a Route-Leak if ALL of
the following conditions hold true: the following conditions hold true:
1. The update is received from a customer AS. 1. The update is received from a customer or lateral peer AS.
2. It is Valid in accordance with the Origin Validation (OV) and 2. It is Valid in accordance with the Origin Validation (OV) and
BGPSEC protocols. (Note: BGPSEC validation is not applicable if BGPSEC protocols. (Note: BGPSEC validation is not applicable if
update is not signed). update is not signed.)
3. The update has the RLP field set to '01' (i.e. 'Do not Propagate 3. The update has the RLP field set to '01' (i.e. 'Do not Propagate
Up') indication for one or more hops (excluding the most recent) Up or Lateral') indication for one or more hops (excluding the
in the AS path. most recent) in the AS path.
The reason for stating "excluding the most recent" in the above The reason for stating "excluding the most recent" in the above
algorithm is as follows. The provider AS already knows that the most algorithm is as follows. An ISP should look at RLP values set by
recent hop in the update is from its customer AS to itself, and it ASes preceding the immediate sending AS in order to ascertain a leak.
does not need to rely on the RLP field value set by the customer for The receiving router already knows that the most recent hop in the
detection of route leaks. update is from its customer or lateral-peer AS to itself, and it does
not need to rely on the RLP field value set by said AS for detection
of route leaks.
A receiving router expects the RLP field value for any hop in the AS A receiving router expects the RLP field value for any hop in the AS
path to be either 00 or 01. However, if a different value (say, 10 path to be either 00 or 01. However, if a different value (say, 10
or 11) is found in the RLP field, then an error condition will get or 11) is found in the RLP field, then an error condition will get
flagged, and any further action is TBD. flagged, and any further action is TBD.
3.2.2. Recommended Actions at a Receiving Router when the Sender is a
Peer
The sender and receiver actions described in Section 3.1 and
Section 3.2.1 clearly help detect and mitigate route leaks of Types
1, 2, and 7. With a slightly modified interpretation of the RLP
encoding on the receiver side, they can be extended to detect lateral
ISP-ISP-ISP route leaks (Type 5) as well as leaks of provider
prefixes to peer (Type 6). (Note: RLP encoding procedure by sending
routers remains the same as described in Section 3.1.)
A recommended receiver algorithm for an ISP to detect a route leak of
either Type 5 or Type 6 is as follows:
A receiving BGPSEC router SHOULD mark an update as a Route-Leak if
ALL of the following conditions hold true:
1. The update is received from a lateral ISP peer.
2. It is Valid in accordance with the Origin Validation (OV) and
BGPSEC protocols. (Note: BGPSEC validation is not applicable if
update is not signed).
3. The update has the RLP field set to '01' indication for one or
more hops (excluding the most recent) in the AS path.
In the above algorithm, the receiving AS interprets the '01'
indication slightly strongly (i.e. stronger than in Section 3.2.1) to
mean "the update SHOULD NOT have been propagated laterally to a peer
ISP like me either". The rationale here is based on the fact that
settlement-free ISP peers accept only customer prefix-routes from
each other. The receiving AS applies the logic that if a preceding
AS (excluding the most recent) set '01' indication, it means that the
update was sent to a peer or a customer by the (preceding) AS, and
the update should not be traversing a lateral peer-to-peer link
subsequently.
3.3. Possible Actions at a Receiving Router for Mitigation 3.3. Possible Actions at a Receiving Router for Mitigation
After applying the above detection algorithm, a receiving router may After applying the above detection algorithm, a receiving router may
use any policy-based algorithm of its own choosing to mitigate any use any policy-based algorithm of its own choosing to mitigate any
detected route leaks. An example receiver algorithm for mitigating a detected route leaks. An example receiver algorithm for mitigating a
route leak is as follows: route leak is as follows:
o If an update from a customer AS is marked as a Route-Leak, then o If an update from a customer or lateral peer AS is marked as a
the receiving router SHOULD prefer a Valid signed update from a 'Route-Leak', then the receiving router SHOULD prefer an alternate
peer or an upstream provider over the customer's update. unmarked route if available.
o If no alternate unmarked route is available, then the route marked
as a 'Route-Leak' MAY be accepted.
A basic principle here is that the presence of '01' value in the RLP A basic principle here is that the presence of '01' value in the RLP
field corresponding to one or more AS hops in the AS path of an field corresponding to one or more AS hops in the AS path of an
update coming from a customer AS informs a receiving router in a update coming from a customer AS informs a receiving router in a
provider AS that a route leak is likely occurring. The provider AS transit-provider AS that a route leak is likely occurring. The
then overrides the "prefer customer route" policy, and instead transit-provider AS then overrides the "prefer customer route"
prefers a route learned from a peer or another upstream provider over policy, and instead prefers an alternate 'clean' route learned from
the customer's route. another customer, a lateral peer, or a transit provider over the
'marked' route from the customer in question.
4. Stopgap Solution when Only Origin Validation is Deployed 4. Stopgap Solution when Only Origin Validation is Deployed
During a phase when BGPSEC path validation has not yet been deployed During a phase when BGPSEC path validation has not yet been deployed
but only origin validation has been deployed, it would be good have a but only origin validation has been deployed, it would be good have a
stopgap solution for route leaks. The stopgap solution can be in the stopgap solution for route leaks. The stopgap solution can be in the
form of construction of a prefix filter list from ROAs. A suggested form of construction of a prefix filter list from ROAs. A suggested
procedure for constructing such a list comprises of the following procedure for constructing such a list comprises of the following
steps: steps:
skipping to change at page 11, line 5 skipping to change at page 10, line 18
(Cust_ROA_List) of valid ROAs that contain any of the ASes in (Cust_ROA_List) of valid ROAs that contain any of the ASes in
Cust_AS_List. Cust_AS_List.
o ISP creates a list of all the prefixes (Cust_Prfx_List) that are o ISP creates a list of all the prefixes (Cust_Prfx_List) that are
contained in any of the ROAs in Cust_ROA_List. contained in any of the ROAs in Cust_ROA_List.
o Cust_Prfx_List is the allowed list of prefixes that is permitted o Cust_Prfx_List is the allowed list of prefixes that is permitted
by the ISP's AS, and will be forwarded by the ISP to upstream by the ISP's AS, and will be forwarded by the ISP to upstream
ISPs, customers, and peers. ISPs, customers, and peers.
o Any prefix not in Cust_Prfx_List but announced by any of the ISP's o A route for a prefix that is not in Cust_Prfx_List but announced
customers is marked as a potential route leak. Then the ISP's by one of ISP's customers is 'marked' as a potential route leak.
router SHOULD prefer a Valid (i.e. valid according to origin Further, the ISP's router SHOULD prefer an alternate route that is
validation) and 'not marked' update from a peer or an upstream Valid (i.e. valid according to origin validation) and 'clean'
provider over the customer's marked update for that prefix. (i.e. not marked) over the 'marked' route. The alternate route
may be from a peer, transit provider, or different customer.
Special considerations with regard to the above procedure may be Special considerations with regard to the above procedure may be
needed for DDoS mitigation service providers. They typically needed for DDoS mitigation service providers. They typically
originate or announce a DDoS victim's prefix to their own ISP on a originate or announce a DDoS victim's prefix to their own ISP on a
short notice during a DDoS emergency. Some provisions would need to short notice during a DDoS emergency. Some provisions would need to
be made for such cases, and they can be determined with the help of be made for such cases, and they can be determined with the help of
inputs from DDoS mitigation service providers. inputs from DDoS mitigation service providers.
For developing a list of all the ASes (Cust_AS_List) that are in the For developing a list of all the ASes (Cust_AS_List) that are in the
customer cone of an ISP, the AS path based Outbound Route Filter customer cone of an ISP, the AS path based Outbound Route Filter
(ORF) technique [draft-ietf-idr-aspath-orf] can be helpful (see (ORF) technique [draft-ietf-idr-aspath-orf] can be helpful (see
discussion in Section 5.2). discussion in Section 5.3).
5. Design Rationale and Discussion 5. Design Rationale and Discussion
In this section, we will try to provide design justifications for the In this section, we will try to provide design justifications for the
methodology specified in Section 3, and also answer some anticipated methodology specified in Section 3, and also answer some questions
questions. that are anticipated or have been raised in IETF IDR/SIDR meetings.
5.1. Is route-leak solution without BGPSEC a serious attack vector? 5.1. Is route-leak solution without BGPSEC a serious attack vector?
It has been asked if a route-leak solution without BGPSEC, i.e. when It has been asked if a route-leak solution without BGPSEC, i.e. when
RLP bits are not protected, can turn into a serious new attack RLP bits are not protected, can turn into a serious new attack
vector. That answer seems to be: not really! Even the NLRI and vector. That answer seems to be: not really! Even the NLRI and
AS_PATH in BGP updates are attack vectors, and RPKI/OV/BGPSEC seek to AS_PATH in BGP updates are attack vectors, and RPKI/OV/BGPSEC seek to
fix that. Consider the following. Say, if 99% of route leaks are fix that. Consider the following. Say, if 99% of route leaks are
accidental and 1% are malicious, and if route-leak solution without accidental and 1% are malicious, and if route-leak solution without
BGPSEC eliminates the 99%, then perhaps it is worth it (step in the BGPSEC eliminates the 99%, then perhaps it is worth it (step in the
right direction). When BGPSEC comes into deployment, the route leak right direction). When BGPSEC comes into deployment, the route leak
protection (RLP) bits can be mapped into BGPSEC (using the Flags protection (RLP) bits can be mapped into BGPSEC (using the Flags
field) and then necessary security will be in place as well (within field) and then necessary security will be in place as well (within
each BGPSEC island as and when they emerge). each BGPSEC island as and when they emerge).
Further, let us consider the worst-case damage that can be caused by Further, let us consider the worst-case damage that can be caused by
maliciously manipulating the RLP bits in an implementation without maliciously manipulating the RLP bits in an implementation without
BGPSEC. An AS that wants to intentionally leak a route would alter BGPSEC. Manipulation of the RLP bits can result in one of two types
the RLP encodings for the preceding hops from '01' (i.e. 'Do not of attacks: (a) Upgrade attack and (b) Downgrade attack.
Propagate Up') to '00' (default) wherever applicable. It is true Descriptions and discussions about these attack follow. In what
that in that case a receiving router would not be able to detect the follows, P2C stands for transit provider to customer (Down); C2P
leak for the specific prefix-route by the RLP mechanism described stands for customer to transit provider (Up), and p2p stands for peer
here. However, the receiving router may still detect and mitigate it to peer (lateral or non-transit relationship).
in some cases by applying other means such as prefix filters
[RFC7454] and AS path filters [draft-ietf-idr-aspath-orf]. If some
malicious leaks go undetected (for RLP without BGPSEC) that is
possibly a small price to pay for the ability to detect the bulk of
route leaks that are accidental.
5.2. Comparison with other methods, routing security BCP (a) Upgrade attack: An AS that wants to intentionally leak a route
would alter the RLP encodings for the preceding hops from '01' (i.e.
'Do not Propagate Up or Lateral') to '00' (default) wherever
applicable. This poses no problem for a route that keeps propagating
in the 'Down' (P2C) direction. However, for a route that propagates
'Up' (C2P) or 'Lateral' (p2p), the worst that can happen is that a
route leak goes undetected. That is, a receiving router would not be
able to detect the leak for the route in question by the RLP
mechanism described here. However, the receiving router may still
detect and mitigate it in some cases by applying other means such as
prefix filters [RFC7454]. If some malicious leaks go undetected
(when RLP is deployed without BGPSEC) that is possibly a small price
to pay for the ability to detect the bulk of route leaks that are
accidental.
(b) Downgrade attack: RLP encoding is set to '01' (i.e. 'Do not
Propagate Up or Lateral') when it should be set to '00' (default).
This would result in a route being mis-detected and marked as a route
leak. By default RLP encoding is set to '00', and that helps reduce
errors of this kind (i.e. accidental downgrade incidents). Every AS
or ISP wants reachability for prefixes it originates and for its
customer prefixes. So an AS or ISP is not likely to change an RLP
value '00' to '01' intentionally. If a route leak is detected (due
to intentional or accidental downgrade) by a receiving router, it
would prefer an alternate 'clean' route from a transit provider or
peer over a 'marked' route from a customer. It may end up with a
suboptimal path. In order to have reachability, the receiving router
would accept a 'marked' route if there is no alternative that is
'clean'. So RLP downgrade attacks (intentional or accidental) would
be quite rare, and the consequences do not appear to be grave.
5.2. Are there cases when valley-free violations can be considered
legitimate?
There are studies in the literature [Anwar] [Giotsas] [Wijchers]
observing and analyzing the behavior of routes announced in BGP
updates using data gathered from the Internet. In particular, the
studies have focused on how often there appear to be valley-free
(e.g. Gao-Rexford [Gao] model) violations, and if they can be
explained [Anwar]. One important consideration for explanation of
violations is per-prefix routing policies, i.e. routes for prefixes
with different business models are often sent over the same link.
One encouraging result reported in [Anwar] is that when per-prefix
routing policies are taken into consideration in the data analysis,
more than 80% of the observed routing decisions fit the valley-free
model (see Section 4.3 and SPA-1 data in Figure 2). The authors in
[Anwar] also observe, "it is well known that this model [the basic
Gao-Rexford model and some variations of it] fails to capture many
aspects of the interdomain routing system. These aspects include AS
relationships that vary based on the geographic region or destination
prefix, and traffic engineering via hot-potato routing or load
balancing." So there may be potential for explaining the remaining
(20% or less) violations of valley-free as well.
One major design factor in the methodology described in this document
is that the Route Leak Protection (RLP) encoding is per prefix. So
the proposed solution is consistent with ISPs' per-prefix routing
policies. Large global and other major ISPs will be the likely early
adopters, and they are expected to have expertise in configuring
policies (including per prefix policies, if applicable), and make
proper use of the RLP indications on a per prefix basis. When said
large ISPs participate in this solution deployment, it is envisioned
that they would form a ring of protection against route leaks, and
co-operatively avoid many of the common types of route leaks that are
observed. Route leaks may still happen occasionally within the
customer cones (if some customer ASes are not participating or not
diligently implementing RLP), but said leaks would be much less
likely to propagate from one large participating ISP to another.
5.3. Comparison with other methods, routing security BCP
It is reasonable to ask if techniques considered in BCPs such It is reasonable to ask if techniques considered in BCPs such
as[RFC7454] (BGP Operations and Security) and [NIST-800-54] may be as[RFC7454] (BGP Operations and Security) and [NIST-800-54] may be
adequate to address route leaks. The prefix filtering adequate to address route leaks. The prefix filtering
recommendations in the BCPs may be complementary but not adequate. recommendations in the BCPs may be complementary but not adequate.
The difficulty is in ISPs' ability to construct prefix filters that The difficulty is in ISPs' ability to construct prefix filters that
represent their customer cones (CC) accurately, especially when there represent their customer cones (CC) accurately, especially when there
are many levels in the hierarchy within the CC. In the RLP-encoding are many levels in the hierarchy within the CC. In the RLP-encoding
based solution described here, AS operators signal for each prefix- based solution described here, AS operators signal for each route
route propagated, if it SHOULD NOT be subsequently propagated to a propagated, if it SHOULD NOT be subsequently propagated to a transit
provider/peer. provider or peer.
AS path based Outbound Route Filter (ORF) described in AS path based Outbound Route Filter (ORF) described in
[draft-ietf-idr-aspath-orf] is also an interesting complementary [draft-ietf-idr-aspath-orf] is also an interesting complementary
technique. It can be used as an automated collaborative messaging technique. It can be used as an automated collaborative messaging
system (implemented in BGP) for ISPs to try to develop a complete system (implemented in BGP) for ISPs to try to develop a complete
view of the ASes and AS paths in their CCs. Once an ISP has that view of the ASes and AS paths in their CCs. Once an ISP has that
view, then AS path filters can be possibly used to detect route view, then AS path filters can be possibly used to detect route
leaks. One limitation of this technique is that it cannot duly take leaks. One limitation of this technique is that it cannot duly take
into account the fact that prefixes with different business models into account the fact that routes for prefixes with different
are often sent over the same link between ASes. Also, the success of business models are often sent over the same link between ASes.
it depends on ASes at all levels of the hierarchy in a CC participate Also, the success of AS path based ORF depends on whether ASes at all
and provide accurate information (in the ORF messages) about the AS levels of the hierarchy in a CC participate and provide accurate
paths they expect to have in their BGP updates to their provider information (in the ORF messages) about the AS paths they expect to
ISP(s). have in their BGP updates.
6. Summary 6. Summary
It should be emphasized once again that the proposed route-leak It should be emphasized once again that the proposed route-leak
detection method using the RLP encoding is not intended to cover all detection method using the RLP encoding is not intended to cover all
forms of route leaks. However, we feel that the solution covers forms of route leaks. However, we feel that the solution covers
several important types of route leaks, especially considering some several important types of route leaks, especially considering some
significant route-leak attacks or occurrences that have been significant route-leak attacks or occurrences that have been
frequently observed in recent years. The solution can be implemented frequently observed in recent years. The solution can be implemented
in BGP without necessarily tying it to BGPSEC. The proposed solution in BGP without necessarily tying it to BGPSEC. The proposed solution
without BGPSEC can detect and mitigate accidental route leaks, and without BGPSEC can detect and mitigate accidental route leaks, and
the same with BGPSEC can detect and mitigate malicious route leaks as the same with BGPSEC can detect and mitigate both accidental and
well. Carrying the proposed RLP encoding in an optional transitive malicious route leaks. Carrying the proposed RLP encoding in an
path attribute in BGP is proposed, but in order to prevent abuse, the optional transitive path attribute in BGP is proposed, but in order
RLP encoding would require cryptographic protection. Incorporating to prevent abuse, the RLP encoding would require cryptographic
the RLP encoding in the BGPSEC Flags field is one way of implementing protection. Incorporating the RLP encoding in the BGPSEC Flags field
it securely using an already existing protection mechanism provided is one way of implementing it securely using an already existing
in BGPSEC path signatures. protection mechanism provided in BGPSEC path signatures.
7. Security Considerations 7. Security Considerations
The proposed Route Leak Protection (RLP) field requires cryptographic The proposed Route Leak Protection (RLP) field requires cryptographic
protection in order to prevent malicious route leaks. Since it is protection in order to prevent malicious route leaks. Since it is
proposed that the RLP field be included in the Flags field in the proposed that the RLP field be included in the Flags field in the
Secure_Path Segment in BPGSEC updates, the cryptographic security Secure_Path Segment in BPGSEC updates, the cryptographic security
mechanisms in BGPSEC are expected to also apply to the RLP field. mechanisms in BGPSEC are expected to also apply to the RLP field.
The reader is therefore directed to the security considerations The reader is therefore directed to the security considerations
provided in [I-D.ietf-sidr-bgpsec-protocol]. provided in [I-D.ietf-sidr-bgpsec-protocol].
8. IANA Considerations 8. IANA Considerations
No updates to the registries are suggested by this document. No updates to the registries are suggested by this document.
9. Acknowledgements 9. Acknowledgements
The authors wish to thank Danny McPherson and Eric Osterweil for The authors wish to thank Danny McPherson and Eric Osterweil for
discussions related to this work. Also, thanks are due to Jared discussions related to this work. Also, thanks are due to Jared
Mauch, Jeff Haas, Warren Kumari, Amogh Dhamdhere, Jakob Heitz, Geoff Mauch, Jeff Haas, Warren Kumari, Amogh Dhamdhere, Jakob Heitz, Geoff
Huston, Randy Bush, Ruediger Volk, Andrei Robachevsky, Sue Hares, Huston, Randy Bush, Ruediger Volk, Sue Hares, Wes George, Chris
Keyur Patel, Wes George, Chris Morrow, and Sandy Murphy for comments, Morrow, and Sandy Murphy for comments, suggestions, and critique.
suggestions, and critique. The authors are also thankful to Padma The authors are also thankful to Padma Krishnaswamy, Oliver Borchert,
Krishnaswamy, Oliver Borchert, and Okhee Kim for their comments and and Okhee Kim for their comments and review.
review.
10. References 10. References
10.1. Normative References 10.1. Normative References
[RFC4271] Rekhter, Y., Li, T., and S. Hares, "A Border Gateway [RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
Protocol 4 (BGP-4)", RFC 4271, January 2006. Border Gateway Protocol 4 (BGP-4)", RFC 4271,
DOI 10.17487/RFC4271, January 2006,
<http://www.rfc-editor.org/info/rfc4271>.
10.2. Informative References 10.2. Informative References
[Anwar] Anwar, R., Niaz, H., Choffnes, D., Cunha, I., Gill, P.,
and N. Katz-Bassett, "Investigating Interdomain Routing
Policies in the Wild", ACM Internet Measurement
Conference (IMC), October 2015,
<http://www.cs.usc.edu/assets/007/94928.pdf>.
[Cowie2010] [Cowie2010]
Cowie, J., "China's 18 Minute Mystery", Dyn Cowie, J., "China's 18 Minute Mystery", Dyn
Research/Renesys Blog, November 2010, Research/Renesys Blog, November 2010,
<http://research.dyn.com/2010/11/ <http://research.dyn.com/2010/11/
chinas-18-minute-mystery/>. chinas-18-minute-mystery/>.
[Cowie2013] [Cowie2013]
Cowie, J., "The New Threat: Targeted Internet Traffic Cowie, J., "The New Threat: Targeted Internet Traffic
Misdirection", Dyn Research/Renesys Blog, November 2013, Misdirection", Dyn Research/Renesys Blog, November 2013,
<http://research.dyn.com/2013/11/ <http://research.dyn.com/2013/11/
skipping to change at page 14, line 36 skipping to change at page 15, line 30
<http://www.cs.princeton.edu/~jrex/papers/ <http://www.cs.princeton.edu/~jrex/papers/
sigmetrics00.long.pdf>. sigmetrics00.long.pdf>.
[Gill] Gill, P., Schapira, M., and S. Goldberg, "A Survey of [Gill] Gill, P., Schapira, M., and S. Goldberg, "A Survey of
Interdomain Routing Policies", ACM SIGCOMM Computer Interdomain Routing Policies", ACM SIGCOMM Computer
Communication Review, January 2014, Communication Review, January 2014,
<https://www.cs.bu.edu/~goldbe/papers/survey.pdf>. <https://www.cs.bu.edu/~goldbe/papers/survey.pdf>.
[Giotsas] Giotsas, V. and S. Zhou, "Valley-free violation in [Giotsas] Giotsas, V. and S. Zhou, "Valley-free violation in
Internet routing - Analysis based on BGP Community data", Internet routing - Analysis based on BGP Community data",
IEEE ICC 2012, June 2012, IEEE ICC 2012, June 2012.
<http://www0.cs.ucl.ac.uk/staff/V.Giotsas/files/
giotsas.icc.2012.pdf>.
[Hiran] Hiran, R., Carlsson, N., and P. Gill, "Characterizing [Hiran] Hiran, R., Carlsson, N., and P. Gill, "Characterizing
Large-scale Routing Anomalies: A Case Study of the China Large-scale Routing Anomalies: A Case Study of the China
Telecom Incident", PAM 2013, March 2013, Telecom Incident", PAM 2013, March 2013,
<http://www3.cs.stonybrook.edu/~phillipa/papers/ <http://www3.cs.stonybrook.edu/~phillipa/papers/
CTelecom.html>. CTelecom.html>.
[Huston2012] [Huston2012]
Huston, G., "Leaking Routes", March 2012, Huston, G., "Leaking Routes", March 2012,
<http://labs.apnic.net/blabs/?p=139/>. <http://labs.apnic.net/blabs/?p=139/>.
[Huston2014] [Huston2014]
Huston, G., "What's so special about 512?", September Huston, G., "What's so special about 512?", September
2014, <http://labs.apnic.net/blabs/?p=520/>. 2014, <http://labs.apnic.net/blabs/?p=520/>.
[I-D.ietf-grow-route-leak-problem-definition] [I-D.ietf-grow-route-leak-problem-definition]
Sriram, K., Montgomery, D., McPherson, D., Osterweil, E., Sriram, K., Montgomery, D., McPherson, D., Osterweil, E.,
and B. Dickson, "Problem Definition and Classification of and B. Dickson, "Problem Definition and Classification of
BGP Route Leaks", draft-ietf-grow-route-leak-problem- BGP Route Leaks", draft-ietf-grow-route-leak-problem-
definition-02 (work in progress), July 2015. definition-03 (work in progress), October 2015.
[I-D.ietf-sidr-bgpsec-protocol] [I-D.ietf-sidr-bgpsec-protocol]
Lepinski, M., "BGPsec Protocol Specification", draft-ietf- Lepinski, M., "BGPsec Protocol Specification", draft-ietf-
sidr-bgpsec-protocol-13 (work in progress), July 2015. sidr-bgpsec-protocol-13 (work in progress), July 2015.
[Kapela-Pilosov] [Kapela-Pilosov]
Pilosov, A. and T. Kapela, "Stealing the Internet: An Pilosov, A. and T. Kapela, "Stealing the Internet: An
Internet-Scale Man in the Middle Attack", DEFCON-16 Las Internet-Scale Man in the Middle Attack", DEFCON-16 Las
Vegas, NV, USA, August 2008, Vegas, NV, USA, August 2008,
<https://www.defcon.org/images/defcon-16/dc16- <https://www.defcon.org/images/defcon-16/dc16-
presentations/defcon-16-pilosov-kapela.pdf/>. presentations/defcon-16-pilosov-kapela.pdf>.
[Khare] Khare, V., Ju, Q., and B. Zhang, "Concurrent Prefix [Khare] Khare, V., Ju, Q., and B. Zhang, "Concurrent Prefix
Hijacks: Occurrence and Impacts", IMC 2012, Boston, MA, Hijacks: Occurrence and Impacts", IMC 2012, Boston, MA,
November 2012, <http://www.cs.arizona.edu/~bzhang/ November 2012, <http://www.cs.arizona.edu/~bzhang/
paper/12-imc-hijack.pdf/>. paper/12-imc-hijack.pdf>.
[Labovitz] [Labovitz]
Labovitz, C., "Additional Discussion of the April China Labovitz, C., "Additional Discussion of the April China
BGP Hijack Incident", Arbor Networks IT Security Blog, BGP Hijack Incident", Arbor Networks IT Security Blog,
November 2010, November 2010,
<http://www.arbornetworks.com/asert/2010/11/additional- <http://www.arbornetworks.com/asert/2010/11/additional-
discussion-of-the-april-china-bgp-hijack-incident/>. discussion-of-the-april-china-bgp-hijack-incident/>.
[LRL] Khare, V., Ju, Q., and B. Zhang, "Large Route Leaks", [LRL] Khare, V., Ju, Q., and B. Zhang, "Large Route Leaks",
Project web page, 2012, Project web page, 2012,
skipping to change at page 16, line 9 skipping to change at page 16, line 51
why-the-internet-broke-today/>. why-the-internet-broke-today/>.
[Mauch] Mauch, J., "BGP Routing Leak Detection System", Project [Mauch] Mauch, J., "BGP Routing Leak Detection System", Project
web page, 2014, web page, 2014,
<http://puck.nether.net/bgp/leakinfo.cgi/>. <http://puck.nether.net/bgp/leakinfo.cgi/>.
[Mauch-nanog] [Mauch-nanog]
Mauch, J., "Detecting Routing Leaks by Counting", Mauch, J., "Detecting Routing Leaks by Counting",
NANOG-41 Albuquerque, NM, USA, October 2007, NANOG-41 Albuquerque, NM, USA, October 2007,
<https://www.nanog.org/meetings/nanog41/presentations/ <https://www.nanog.org/meetings/nanog41/presentations/
mauch-lightning.pdf/>. mauch-lightning.pdf>.
[NIST-800-54] [NIST-800-54]
Kuhn, D., Sriram, K., and D. Montgomery, "Border Gateway Kuhn, D., Sriram, K., and D. Montgomery, "Border Gateway
Protocol Security", NIST Special Publication 800-54, July Protocol Security", NIST Special Publication 800-54, July
2007, <http://csrc.nist.gov/publications/nistpubs/800-54/ 2007, <http://csrc.nist.gov/publications/nistpubs/800-54/
SP800-54.pdf>. SP800-54.pdf>.
[Paseka] Paseka, T., "Why Google Went Offline Today and a Bit about [Paseka] Paseka, T., "Why Google Went Offline Today and a Bit about
How the Internet Works", CloudFare Blog, November 2012, How the Internet Works", CloudFare Blog, November 2012,
<http://blog.cloudflare.com/ <http://blog.cloudflare.com/
skipping to change at page 16, line 45 skipping to change at page 17, line 39
<http://www.rfc-editor.org/info/rfc6811>. <http://www.rfc-editor.org/info/rfc6811>.
[RFC7454] Durand, J., Pepelnjak, I., and G. Doering, "BGP Operations [RFC7454] Durand, J., Pepelnjak, I., and G. Doering, "BGP Operations
and Security", BCP 194, RFC 7454, DOI 10.17487/RFC7454, and Security", BCP 194, RFC 7454, DOI 10.17487/RFC7454,
February 2015, <http://www.rfc-editor.org/info/rfc7454>. February 2015, <http://www.rfc-editor.org/info/rfc7454>.
[Toonk] Toonk, A., "What Caused Today's Internet Hiccup", August [Toonk] Toonk, A., "What Caused Today's Internet Hiccup", August
2014, <http://www.bgpmon.net/ 2014, <http://www.bgpmon.net/
what-caused-todays-internet-hiccup/>. what-caused-todays-internet-hiccup/>.
[Toonk2015-A]
Toonk, A., "What caused the Google service interruption",
March 2015, <http://www.bgpmon.net/
what-caused-the-google-service-interruption/>.
[Toonk2015-B]
Toonk, A., "Massive route leak causes Internet slowdown",
June 2015, <http://www.bgpmon.net/
massive-route-leak-cause-internet-slowdown/>.
[Wijchers] [Wijchers]
Wijchers, B. and B. Overeinder, "Quantitative Analysis of Wijchers, B. and B. Overeinder, "Quantitative Analysis of
BGP Route Leaks", RIPE-69, November 2014, BGP Route Leaks", RIPE-69, November 2014,
<https://ripe69.ripe.net/presentations/157-RIPE-69- <https://ripe69.ripe.net/presentations/157-RIPE-69-
Routing-WG.pdf>. Routing-WG.pdf>.
[Zmijewski] [Zmijewski]
Zmijewski, E., "Indonesia Hijacks the World", Dyn Zmijewski, E., "Indonesia Hijacks the World", Dyn
Research/Renesys Blog, April 2014, Research/Renesys Blog, April 2014,
<http://research.dyn.com/2014/04/ <http://research.dyn.com/2014/04/
skipping to change at page 17, line 24 skipping to change at page 18, line 30
US NIST US NIST
Email: ksriram@nist.gov Email: ksriram@nist.gov
Doug Montgomery Doug Montgomery
US NIST US NIST
Email: dougm@nist.gov Email: dougm@nist.gov
Brian Dickson Brian Dickson
Twitter, Inc.
Email: bdickson@twitter.com Email: brian.peter.dickson@gmail.com
Keyur Patel
Cisco
Email: keyupate@cisco.com
Andrei Robachevsky
Internet Society
Email: robachevsky@isoc.org
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