draft-ietf-grow-route-leak-detection-mitigation-03.txt   draft-ietf-grow-route-leak-detection-mitigation-04.txt 
IDR and SIDR K. Sriram, Ed. IDR and SIDR K. Sriram, Ed.
Internet-Draft USA NIST Internet-Draft USA NIST
Intended status: Standards Track A. Azimov, Ed. Intended status: Standards Track A. Azimov, Ed.
Expires: January 28, 2021 Yandex Expires: April 29, 2021 Yandex
July 27, 2020 October 26, 2020
Methods for Detection and Mitigation of BGP Route Leaks Methods for Detection and Mitigation of BGP Route Leaks
draft-ietf-grow-route-leak-detection-mitigation-03 draft-ietf-grow-route-leak-detection-mitigation-04
Abstract Abstract
Problem definition for route leaks and enumeration of types of route Problem definition for route leaks and enumeration of types of route
leaks are provided in RFC 7908. This document describes a new well- leaks are provided in RFC 7908. This document describes a new well-
known Large Community that provides a way for route-leak prevention, known Large Community that provides a way for route-leak prevention,
detection, and mitigation. The configuration process for this detection, and mitigation. The configuration process for this
Community can be automated with the methodology for setting BGP roles Community can be automated with the methodology for setting BGP roles
that is described in ietf-idr-bgp-open-policy draft. that is described in ietf-idr-bgp-open-policy draft.
skipping to change at page 1, line 36 skipping to change at page 1, line 36
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This Internet-Draft will expire on January 28, 2021. This Internet-Draft will expire on April 29, 2021.
Copyright Notice Copyright Notice
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. Peering Relationships . . . . . . . . . . . . . . . . . . . . 3 2. Peering Relationships . . . . . . . . . . . . . . . . . . . . 3
3. Community vs Attribute . . . . . . . . . . . . . . . . . . . 3 3. Community vs Attribute . . . . . . . . . . . . . . . . . . . 3
4. Down Only Community . . . . . . . . . . . . . . . . . . . . . 4 4. Down Only Community . . . . . . . . . . . . . . . . . . . . . 4
4.1. Route-Leak Mitigation . . . . . . . . . . . . . . . . . . 5 4.1. Route-Leak Mitigation . . . . . . . . . . . . . . . . . . 5
4.2. Only Marking . . . . . . . . . . . . . . . . . . . . . . 6 4.2. Only Marking . . . . . . . . . . . . . . . . . . . . . . 6
5. Implementation Considerations . . . . . . . . . . . . . . . . 7 5. Implementation Considerations . . . . . . . . . . . . . . . . 7
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
7. Security Considerations . . . . . . . . . . . . . . . . . . . 7 7. Security Considerations . . . . . . . . . . . . . . . . . . . 8
8. Informative References . . . . . . . . . . . . . . . . . . . 7 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 8 8.1. Normative References . . . . . . . . . . . . . . . . . . 8
Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 8 8.2. Informative References . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 9
Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction 1. Introduction
RFC 7908 [RFC7908] provides a definition of the route-leak problem RFC 7908 [RFC7908] provides a definition of the route-leak problem
and enumerates several types of route leaks. For this document, the and enumerates several types of route leaks. For this document, the
definition that is applied is that a route leak occurs when a route definition that is applied is that a route leak occurs when a route
received from a transit provider or a lateral peer is forwarded received from a transit provider or a lateral peer is forwarded
(against commonly used policy) to another transit provider or a (against commonly used policy) to another transit provider or a
lateral peer. The commonly used policy is that a route received from lateral peer. The commonly used policy is that a route received from
a transit provider or a lateral peer MAY be forwarded only to a transit provider or a lateral peer MAY be forwarded only to
customers. customers.
This document describes a solution for prevention, detection and This document describes a solution for prevention, detection and
mitigation route leaks which is based on conveying route-leak mitigation of route leaks which is based on conveying route-leak
detection information in a transitive well-known BGP Large Community. detection information in a transitive well-known BGP Large Community
The configuration process for the Large Community MUST be defined [RFC8092]. The configuration process for the Large Community MUST be
according to peering relations between ISPs. This process can be defined according to peering relations between ISPs. This process
automated with the methodology for setting BGP roles that is can be automated with the methodology for setting BGP roles that is
described in [I-D.ietf-idr-bgp-open-policy]. described in [I-D.ietf-idr-bgp-open-policy].
The techniques described in this document can be incrementally The techniques described in this document can be incrementally
deployed. If a pair of ISPs and/or Internet Exchanges (IXes) deploy deployed. If a pair of ISPs and/or Internet Exchanges (IXes) deploy
the proposed techniques, then they would detect and mitigate any the proposed techniques, then they would detect and mitigate any
route leaks that occur in an AS path between them even when other route leaks that occur in an AS path between them even when other
ASes in the path are not upgraded. ASes in the path are not upgraded.
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. Peering Relationships 2. Peering Relationships
As described in [I-D.ietf-idr-bgp-open-policy] there are several As described in [I-D.ietf-idr-bgp-open-policy] there are several
common peering relations between eBGP neighbors: common peering relations between eBGP neighbors:
o Provider - sender is a transit provider of the neighbor; o Provider - sender is a transit provider of the neighbor;
o Customer - sender is a customer of the neighbor; o Customer - sender is a customer of the neighbor;
o Route Server (RS) - sender is route server at an internet exchange o Route Server (RS) - sender is route server at an internet exchange
(IX) (IX)
o RS-client - sender is client of an RS at an IX o RS-client - sender is client of an RS at an IX
o Peer - sender and neighbor are lateral (non-transit) peers; o Peer - sender and neighbor are lateral (non-transit) peers;
If a route is received from a provider, peer or RS-client, it MUST If a route is received from a provider, peer, or RS-client, it MUST
follow the 'down only' rule, i.e., it MAY be advertised only to follow the 'down only' rule, i.e., it MAY be advertised only to
customers. If a route is sent to a customer, peer or RS-client, it customers. If a route is sent to a customer, peer, or RS-client, it
also MUST follow the 'down only' rule at each subsequent AS in the AS also MUST follow the 'down only' rule at each subsequent AS in the AS
path. path.
A standardized transitive route-leak detection signal is needed that A standardized transitive route-leak detection signal is needed that
will prevent Autonomous Systems (ASes) from leaking and also inform a will prevent Autonomous Systems (ASes) from leaking and also inform a
remote ISP (or AS) in the AS path that a received route violates remote ISP (or AS) in the AS path that a received route violates the
'down only' policy. This signal would facilitate a way to stop the 'down only' policy. This signal would facilitate a way to stop the
propagation of leaked prefixes. propagation of leaked prefixes.
To improve reliability and cover for non-participating preceding To improve reliability and cover for non-participating preceding
neighbor, the signal should be set on both receiver and sender sides. neighbor, the signal should be set on both receiver and sender sides.
3. Community vs Attribute 3. Community vs Attribute
This section presents a brief discussion of the advantages and This section presents a brief discussion of the advantages and
disadvantages of communities and BGP path attributes for the purpose disadvantages of communities and BGP path attributes for the purpose
of route-leak detection. of route-leak detection.
A transitive path attribute is a native way to implement the route- A transitive path attribute is a native way to implement the route-
leak detection signal. Based on the way BGP protocol works, the use leak detection signal. Based on the way BGP protocol works, the use
of a transitive attribute makes it more certain that the route-leak of a transitive attribute makes it more certain that the route-leak
detection signal would pass unaltered through non-participating detection signal would pass unaltered through non-participating
(i.e., not upgraded) BGP routers. The main disadvantage of this (i.e., not upgraded) BGP routers. The main disadvantage of this
approach is that the deployment of a new BGP attribute requires a approach is that the deployment of a new BGP attribute requires a
software upgrade in router OS which may delay wide adoption for software upgrade in the router OS which may delay wide adoption for
years. years.
On the other hand, BGP Communities do not require a router OS update. On the other hand, BGP Communities do not require a router OS update.
The potential disadvantage of using a Community for the route-leak The potential disadvantage of using a Community for the route-leak
detection signal is that it is more likely to be dropped somewhere detection signal is that it is more likely to be dropped somewhere
along the way in the AS path. Currently, the use of BGP Communities along the way in the AS path. Currently, the use of BGP Communities
is somewhat overloaded. BGP Communities are already used for is somewhat overloaded. BGP Communities are already used for
numerous applications: different types of route marking, route policy numerous applications: different types of route marking, route policy
control, blackholing, etc. It is observed that some ASes seem to control, blackholing, etc. It is observed that some ASes seem to
purposefully or accidentally remove transitive communities on purposefully or accidentally remove BGP Communities on receipt,
receipt, sometimes well-known ones. Perhaps this issue may be sometimes well-known ones. Perhaps this issue may be mitigated with
mitigated with strong policy guidance related to the handling of strong policy guidance related to the handling of Communities.
Communities.
Due to frequently occurring regional and global disruptions in
Internet connectivity, it is critical to move forward with a solution
that is viable in the near term. That solution would be route-leak
detection using BGP Community.
Large Communities have much higher capacity, and therefore they are Large Communities have much higher capacity, and therefore they are
likely to be less overloaded. Hence, Large Community is proposed to likely to be less overloaded. Hence, Large Community is proposed to
be used for route-leak detection. This document suggests reserving be used for route-leak detection. This document suggests reserving
<TBD1> class for the purpose of transitive well-known Large <TBD1> class for the purpose of transitive well-known Large
Communities that MUST NOT be stripped on ingress or egress. Communities that MUST NOT be stripped on ingress or egress.
While it is not a part of this document, the route-leak detection While it is not a part of this document, the route-leak detection
signal described here can also be carried in a transitive BGP Path signal described here can also be carried in a transitive BGP Path
Attribute, and similar prevention and mitigation techniques as Attribute, and similar prevention and mitigation techniques as
described here would apply (see [I-D.ietf-idr-bgp-open-policy]). described here would apply (see [I-D.ietf-idr-bgp-open-policy]).
Due to frequently occurring regional and global disruptions in
Internet connectivity, it is critical to move forward with a solution
that is viable in the near term. That solution would be route-leak
detection using a well-known Large Community.
4. Down Only Community 4. Down Only Community
This section specifies the semantics of route-leak detection This section specifies the semantics of route-leak detection
Community and its usage. This Community is given the specific name Community and its usage. This Community is given the specific name
Down Only (DO) Community. The DO Community is carried in a BGP Large Down Only (DO) Community. The DO Community is carried in a BGP Large
Community with a format as shown in Figure 1. Community with a format as shown in Figure 1.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TBD1 (class for transitive well-known Large Communities) | | TBD1 (class for transitive well-known Large Communities) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TBD2 (subclass for DO) | | TBD2 (subclass for DO) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ASN | | ASN |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: Format of the DO Community using a Large Community Figure 1: Format of the DO Community using a BGP Large Community.
[RFC8092].
The authors studied different options for route-leak mitigation. The The authors studied different options for route-leak mitigation. The
main options considered are (1) drop detected route leaks and (2) main options considered are (1) drop detected route leaks and (2)
deprioritize detected route leaks. It can be demonstrated that the deprioritize detected route leaks. It can be demonstrated that the
loose mode that uses deprioritization is not safe. Traffic loose mode that uses deprioritization is not safe. Traffic
Engineering (TE) techniques which limit prefix visibility are quite Engineering (TE) techniques which limit prefix visibility are quite
common. It may happen that a more specific TE prefix is sent only to common. It may happen that a more specific TE prefix is sent only to
downstream ASes or to IX(es)/selected peers, and a control Community downstream ASes or to IX(es)/selected peers, and a control Community
is used to restrict its propagation. If such a more specific prefix is used to restrict its propagation. If such a more specific prefix
is leaked, deprioritization will not stop such a route leak from is leaked, deprioritization will not stop such a route leak from
skipping to change at page 5, line 32 skipping to change at page 5, line 44
Nevertheless, early adopters might want to deploy only the signaling Nevertheless, early adopters might want to deploy only the signaling
and perhaps use it only for diagnostics before applying any route- and perhaps use it only for diagnostics before applying any route-
leak mitigation policy. They are also encouraged to use slightly leak mitigation policy. They are also encouraged to use slightly
limited marking, which is described in Section 4.2. limited marking, which is described in Section 4.2.
4.1. Route-Leak Mitigation 4.1. Route-Leak Mitigation
This section describes the eBGP ingress and egress policies that MUST This section describes the eBGP ingress and egress policies that MUST
be used to perform route-leak prevention, detection and mitigation be used to perform route-leak prevention, detection and mitigation
using the DO Community. using the DO Community. It should be noted that a route may carry
more than one DO Communities. Hence, in the rest of this document,
"a route with DO Community" means "a route with one or more DO
Communities".
The ingress policy MUST use the following procedure: The ingress policy MUST use the following procedure:
1. If a route with DO Community set (i.e., DO is attached) is 1. If a route with DO Community is received from a Customer or RS-
received from a Customer or RS-client, then it is a route leak client, then it is a route leak and MUST be dropped. The
and MUST be rejected. The procedure halts. procedure halts.
2. If a route with DO Community set is received from Peer (non- 2. If a route with DO Community is received from a Peer (non-
transit) and DO value is not equal to the sending neighbor's ASN, transit) and at least one DO value is not equal to the sending
then it is a route leak and MUST be rejected. The procedure neighbor's ASN, then it is a route leak and MUST be dropped. The
halts. procedure halts.
3. If a route is received from a Provider, Peer or RS, then the DO 3. If a route is received from a Provider, Peer, or RS, then a DO
Community MUST be added with a value equal to the sending Community MUST be added with a value equal to the sending
neighbor's ASN. neighbor's ASN.
The egress policy MUST use the following procedure: The egress policy MUST use the following procedure:
1. A route with DO Community set MUST NOT be sent to Providers, 1. A route with DO Community (i.e., DO Community was present or
Peers, and RS. added at ingress) MUST NOT be sent to a Provider, Peer, or RS.
2. If a route is sent to a Customer or Peer, then the DO Community 2. If a route is sent to a Customer or Peer, then a DO Community
MUST be added with a value equal to the ASN of the sender. MUST be added with value equal to the ASN of the sender.
The above procedures comprehensively provide route-leak prevention, The above procedures comprehensively provide route-leak prevention,
detection and mitigation. Policy consisting of these procedures detection and mitigation. Policy consisting of these procedures
SHOULD be used as a default behavior. SHOULD be used as a default behavior.
4.2. Only Marking 4.2. Only Marking
This section describes eBGP ingress and egress marking policies that This section describes eBGP ingress and egress marking policies that
MUST be used if an AS is not performing route-leak mitigation (i.e., MUST be used if an AS is not performing route-leak mitigation (i.e.,
dropping detected route leaks) as described in Section 4.1, but wants not dropping detected route leaks) as described in Section 4.1, but
to use only marking with DO Community. The slightly limited DO wants to use the DO Community only for marking. The slightly limited
marking (compared to that in Section 4.1) described below guarantees DO marking (compared to that in Section 4.1) described below
that this DO marking will not limit the leak detection opportunities guarantees that this DO marking will not limit the leak detection
for subsequent ASes in the AS path. opportunities for subsequent ASes in the AS path.
The ingress policy MUST use the following procedure: The ingress policy MUST use the following procedure:
1. If a route with DO Community set is received from a Customer or 1. If a route with DO Community is received from a Customer or RS-
RS-client, then it is a route leak. The procedure halts. client, then it is a route leak. The procedure halts.
2. If a route with DO Community set is received from a Peer and DO 2. If a route with DO Community is received from a Peer (non-
value is not equal to the sending neighbor's ASN, then it is a transit) and at least one DO value is not equal to the sending
route leak. The procedure halts. neighbor's ASN, then it is a route leak. The procedure halts.
3. If a route is received from a Provider, Peer or RS, then the DO 3. If a route is received from a Provider, Peer, or RS, then a DO
Community MUST be added with value equal to the sending Community MUST be added with value equal to the sending
neighbor's ASN. neighbor's ASN.
The egress policy MUST use the following procedure: The egress policy MUST use the following procedure:
1. If a route is sent to a Customer or RS-client, then the DO 1. If a route is sent to a Customer or RS-client, then a DO
Community MUST be added with value equal to the ASN of the Community MUST be added with value equal to the ASN of the
sender. sender.
2. If DO Community is not set and the route is sent to a Peer, then 2. If a route without DO Community is sent to a Peer, then a DO
the DO Community MUST be added with value equal to the ASN of the Community MUST be added with value equal to the ASN of the
sender. sender. Conversely, if a route with DO Community (i.e., DO
Community was present or added at ingress) is sent to a Peer,
then an additional DO Community MUST NOT be added.)
These above procedures specify setting DO signal in a way that can be These above procedures specify setting the DO signals in a way that
used to evaluate the potential impact of route-leak mitigation policy can be used to evaluate the potential impact of route-leak mitigation
before deploying strict dropping of detected route leaks. policy before deploying strict dropping of detected route leaks.
5. Implementation Considerations 5. Implementation Considerations
It was observed that the majority of BGP implementations do not It was observed that the majority of BGP implementations do not
support negative match for communities like a:b:!c. Considering that support negative match for communities like a:b:!c. Further, it is
it is suggested to replace the second rule from ingress policy with observed that a route received from a compliant Peer (non-transit)
the following: adhering to procedures from either Section 4.1 or Section 4.2 will
always have a single DO Community with value equal to the peer's ASN.
Hence, it is suggested to replace the second rule from the ingress
policies (in Section 4.1 and Section 4.2) with the following:
If a route with DO Community set is received from a Peer and DO value In Section 4.1: If a route with DO Community is received from a
is equal to the sending neighbor's ASN, then it is a valid route, Peer and a DO value is equal to the sending neighbor's ASN, then
otherwise it is a route leak. The procedure halts. it is a valid route, otherwise it is a route leak and MUST be
dropped. The procedure halts.
In Section 4.2: If a route with DO Community is received from a
Peer and a DO value is equal to the sending neighbor's ASN, then
it is a valid route, otherwise it is a route leak. The procedure
halts.
This rule is based on a weaker assumption that a peer that is doing This rule is based on a weaker assumption that a peer that is doing
marking is also doing filtering (dropping detected leaks). That is marking is also doing filtering (i.e., dropping detected leaks).
why networks that do not follow the route-leak mitigation policy in That is why networks that do not follow the route-leak mitigation
Section 4.1 MUST carefully follow marking rules described in policy in Section 4.1 MUST carefully follow marking rules described
Section 4.2. in Section 4.2.
6. IANA Considerations 6. IANA Considerations
The draft suggests to reserve a Global Administrator ID <TBD1> for IANA is requested to reserve a Global Administrator ID <TBD1> for
transitive well-known Large Community registry. IANA is requested to transitive well-known Large Community registry. IANA is also
register a subclass <TBD2> for DO Community in this registry. requested to register a subclass <TBD2> for DO Community in this
registry.
7. Security Considerations 7. Security Considerations
In specific circumstances in a state of partial adoption, route-leak In specific circumstances in a state of partial adoption, route-leak
mitigation mechanism can result in Denial of Service (DoS) for the mitigation mechanism can result in Denial of Service (DoS) for the
victim prefix. Such a scenario may happen only for a prefix that has victim prefix. Such a scenario may happen only for a prefix that has
a single path from the originator to a Tier-1 ISP and only when the a single path from the originator to a Tier-1 ISP and only when the
prefix is not covered with a less specific prefix with multiple paths prefix is not covered with a less specific prefix with multiple paths
to the Tier-1 ISP. If, in such unreliable topology, route leak is to the Tier-1 ISP. If, in such unreliable topology, a route leak is
injected somewhere inside this single path, then it may be rejected injected somewhere inside this single path, then it may be dropped by
by upper layer providers in the path, thus limiting prefix upper tier providers in the path, thus limiting prefix visibility.
visibility. While such anomaly is unlikely to happen, such an issue While such anomaly is unlikely to happen, such an issue should be
should be easy to debug, since it directly affects the sequence of easy to debug, since it directly affects the sequence of originator's
originator's providers. providers.
With the use of BGP Community, there is often a concern that the With the use of BGP Community, there is often a concern that the
Community propagates beyond its intended perimeter and causes harm Community propagates beyond its intended perimeter and causes harm
[streibelt]. However, that concern does not apply to the DO [streibelt]. However, that concern does not apply to the DO
Community because it is a transitive Community that must propagate as Community because it is a transitive Community that must propagate as
far as the update goes. far as the update goes.
8. Informative References 8. References
8.1. 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>.
[RFC8092] Heitz, J., Ed., Snijders, J., Ed., Patel, K., Bagdonas,
I., and N. Hilliard, "BGP Large Communities Attribute",
RFC 8092, DOI 10.17487/RFC8092, February 2017,
<https://www.rfc-editor.org/info/rfc8092>.
[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>.
8.2. Informative References
[I-D.ietf-idr-bgp-open-policy] [I-D.ietf-idr-bgp-open-policy]
Azimov, A., Bogomazov, E., Bush, R., Patel, K., and K. Azimov, A., Bogomazov, E., Bush, R., Patel, K., and K.
Sriram, "Route Leak Prevention using Roles in Update and Sriram, "Route Leak Prevention using Roles in Update and
Open messages", draft-ietf-idr-bgp-open-policy-13 (work in Open messages", draft-ietf-idr-bgp-open-policy-13 (work in
progress), July 2020. progress), July 2020.
[RFC4264] Griffin, T. and G. Huston, "BGP Wedgies", RFC 4264, [RFC4264] Griffin, T. and G. Huston, "BGP Wedgies", RFC 4264,
DOI 10.17487/RFC4264, November 2005, DOI 10.17487/RFC4264, November 2005,
<https://www.rfc-editor.org/info/rfc4264>. <https://www.rfc-editor.org/info/rfc4264>.
[RFC7908] Sriram, K., Montgomery, D., McPherson, D., Osterweil, E., [RFC7908] 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", RFC 7908, DOI 10.17487/RFC7908, June BGP Route Leaks", RFC 7908, DOI 10.17487/RFC7908, June
2016, <https://www.rfc-editor.org/info/rfc7908>. 2016, <https://www.rfc-editor.org/info/rfc7908>.
[RFC8092] Heitz, J., Ed., Snijders, J., Ed., Patel, K., Bagdonas,
I., and N. Hilliard, "BGP Large Communities Attribute",
RFC 8092, DOI 10.17487/RFC8092, February 2017,
<https://www.rfc-editor.org/info/rfc8092>.
[streibelt] [streibelt]
Streibelt et al., F., "BGP Communities: Even more Worms in Streibelt et al., F., "BGP Communities: Even more Worms in
the Routing Can", ACM IMC, October 2018, the Routing Can", ACM IMC, October 2018,
<https://archive.psg.com//181101.imc-communities.pdf>. <https://archive.psg.com//181101.imc-communities.pdf>.
Acknowledgements Acknowledgements
The authors wish to thank John Scudder, Susan Hares, Ruediger Volk, The authors wish to thank John Scudder, Susan Hares, Ruediger Volk,
Jeffrey Haas, Mat Ford, Greg Skinner for their review and comments. Jeffrey Haas, Mat Ford, Greg Skinner for their review and comments.
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