draft-ietf-grow-bgp-reject-08.txt   rfc8212.txt 
Global Routing Operations J. Mauch Internet Engineering Task Force (IETF) J. Mauch
Internet-Draft Akamai Request for Comments: 8212 Akamai
Updates: 4271 (if approved) J. Snijders Updates: 4271 J. Snijders
Intended status: Standards Track NTT Category: Standards Track NTT
Expires: November 25, 2017 G. Hankins ISSN: 2070-1721 G. Hankins
Nokia Nokia
May 24, 2017 July 2017
Default EBGP Route Propagation Behavior Without Policies Default External BGP (EBGP) Route Propagation Behavior without Policies
draft-ietf-grow-bgp-reject-08
Abstract Abstract
This document updates RFC4271 by defining the default behavior of a This document updates RFC 4271 by defining the default behavior of a
BGP speaker when there is no Import or Export Policy associated with BGP speaker when there is no Import or Export Policy associated with
an External BGP session. an External BGP session.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This is an Internet Standards Track document.
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
This Internet-Draft will expire on November 25, 2017. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc8212.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
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the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Changes to RFC4271 . . . . . . . . . . . . . . . . . . . . . 3 2.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
4. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 4 3. Changes to RFC 4271 . . . . . . . . . . . . . . . . . . . . . 3
5. Security Considerations . . . . . . . . . . . . . . . . . . . 4 4. Security Considerations . . . . . . . . . . . . . . . . . . . 4
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 4 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 4
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 6.1. Normative References . . . . . . . . . . . . . . . . . . 4
8.1. Normative References . . . . . . . . . . . . . . . . . . 5 6.2. Informative References . . . . . . . . . . . . . . . . . 5
8.2. Informative References . . . . . . . . . . . . . . . . . 5 Appendix A. Transition Considerations for BGP Implementers . . . 6
Appendix A. Transition Considerations for BGP Implementers . . . 5 A.1. "N+1 N+2" Release Strategy . . . . . . . . . . . . . . . 6
A.1. "N+1 N+2" Release Strategy . . . . . . . . . . . . . . . 5 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction 1. Introduction
BGP routing security issues need to be addressed in order to make the BGP routing security issues need to be addressed in order to make the
Internet more stable. Route leaks [RFC7908] are part of the problem, Internet more stable. Route leaks [RFC7908] are part of the problem,
but software defects or operator misconfiguration can contribute too. but software defects or operator misconfiguration can also
This document updates [RFC4271] so that routes are neither imported contribute. This document updates [RFC4271] so that routes are
nor exported unless specifically enabled by configuration. This neither imported nor exported unless specifically enabled by
change reduces the consequences of these problems, and improves the configuration. This change reduces the consequences of these
default level of Internet routing security. problems and improves the default level of Internet routing security.
Many deployed BGP speakers send and accept any and all route Many deployed BGP speakers send and accept any and all route
announcements between their BGP neighbors by default. This practice announcements between their BGP neighbors by default. This practice
dates back to the early days of the Internet, where operators were dates back to the early days of the Internet, where operators were
permissive in sending routing information to allow all networks to permissive in sending routing information to allow all networks to
reach each other. As the Internet has become more densely reach each other. As the Internet has become more densely
interconnected, the risk of a misbehaving BGP speaker poses interconnected, the risk of a misbehaving BGP speaker poses
significant risks to Internet routing. significant risks to Internet routing.
This specification intends to improve this situation by requiring the This specification intends to improve this situation by requiring the
explicit configuration of both BGP Import and Export Policies for any explicit configuration of both BGP Import and Export Policies for any
External BGP (EBGP) session such as customers, peers, or External BGP (EBGP) session such as customers, peers, or
confederation boundaries for all enabled address families. Through confederation boundaries for all enabled address families. Through
codification of the aforementioned requirement, operators will codification of the aforementioned requirement, operators will
benefit from consistent behaviour across different BGP benefit from consistent behavior across different BGP
implementations. implementations.
BGP speakers following this specification do not use or send routes BGP speakers following this specification do not use or send routes
on EBGP sessions, unless specifically configured to do so. on EBGP sessions, unless specifically configured to do so.
2. Terminology 2. Terminology
[RFC4271] describes a Policy Information Base (PIB) which contains [RFC4271] describes a Policy Information Base (PIB) that contains
local policies that can be applied to the information in the Routing local policies that can be applied to the information in the Routing
Information Base (RIB). This document distinguishes the type of a Information Base (RIB). This document distinguishes the type of a
policy based on its application. policy based on its application.
Import Policy: a local policy to be applied to the information Import Policy: a local policy to be applied to the information
contained in the Adj-RIBs-In. As described in Section 3.2 [RFC4271], contained in the Adj-RIBs-In. As described in Section 3.2 [RFC4271],
the Adj-RIBs-In contain information learned from other BGP speakers, the Adj-RIBs-In contain information learned from other BGP speakers,
and the application of the Import Policy results in the routes that and the application of the Import Policy results in the routes that
will be considered in the Decision Process by the local BGP speaker. will be considered in the Decision Process by the local BGP speaker.
Export Policy: a local policy to be applied in selecting the Export Policy: a local policy to be applied in selecting the
information contained in the Adj-RIBs-Out. As described in information contained in the Adj-RIBs-Out. As described in
Section 3.2 [RFC4271], the Adj-RIBs-Out contain information that has Section 3.2 [RFC4271], the Adj-RIBs-Out contain information that has
been selected for advertisement to other BGP speakers. been selected for advertisement to other BGP speakers.
3. Changes to RFC4271 2.1. 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.
3. Changes to RFC 4271
This section updates [RFC4271] to specify the default behavior of a This section updates [RFC4271] to specify the default behavior of a
BGP speaker when there are no Import or Export Policies associated BGP speaker when there are no Import or Export Policies associated
with a particular EBGP session. A BGP speaker MAY provide a with a particular EBGP session. A BGP speaker MAY provide a
configuration option to deviate from the following updated behaviors. configuration option to deviate from the following updated behaviors.
The following paragraph is added to Section 9.1 (Decision Process) The following paragraph is added to Section 9.1 (Decision Process)
after the fifth paragraph, which ends in "route aggregation and route after the fifth paragraph, which ends in "route aggregation and route
information reduction": information reduction":
skipping to change at page 4, line 5 skipping to change at page 4, line 5
SHALL NOT be considered eligible in the Decision Process if no SHALL NOT be considered eligible in the Decision Process if no
explicit Import Policy has been applied. explicit Import Policy has been applied.
The following paragraph is added to Section 9.1.3 (Phase 3: Route The following paragraph is added to Section 9.1.3 (Phase 3: Route
Dissemination) after the third paragraph, which ends in "by means of Dissemination) after the third paragraph, which ends in "by means of
an UPDATE message (see 9.2).": an UPDATE message (see 9.2).":
Routes SHALL NOT be added to an Adj-RIB-Out associated with an Routes SHALL NOT be added to an Adj-RIB-Out associated with an
EBGP peer if no explicit Export Policy has been applied. EBGP peer if no explicit Export Policy has been applied.
4. Acknowledgments 4. Security Considerations
The authors would like to thank the following people for their
comments, support and review: Shane Amante, Christopher Morrow,
Robert Raszuk, Greg Skinner, Adam Chappell, Sriram Kotikalapudi,
Brian Dickson, Jeffrey Haas, John Heasley, Ignas Bagdonas, Donald
Smith, Dale Worley, Alvaro Retana, John Scudder, and Dale Worley.
5. Security Considerations
Permissive default routing policies can result in inadvertent effects Permissive default routing policies can result in inadvertent effects
such as route leaks [RFC7908], in general resulting in routing of such as route leaks [RFC7908], in general resulting in routing of
traffic through an unexpected path. While it is possible for an traffic through an unexpected path. While it is possible for an
operator to use monitoring to detect unexpected flows, there is no operator to use monitoring to detect unexpected flows, there is no
general framework that can be applied. These policies also have the general framework that can be applied. These policies also have the
potential to expose software defects or misconfiguration that could potential to expose software defects or misconfiguration that could
have unforeseen technical and business impacting effects. have unforeseen technical and business impacting effects.
The update to [RFC4271] specified in this document is intended to The update to [RFC4271] specified in this document is intended to
eliminate those inadvertent effects. Operators must explicitly eliminate those inadvertent effects. Operators must explicitly
configure Import and Export Policies to achieve their expected goals. configure Import and Export Policies to achieve their expected goals.
There is of course no protection against a malicious or incorrect There is of course no protection against a malicious or incorrect
explicit configuration. explicit configuration.
The security considerations described in [RFC4271] and the The security considerations described in [RFC4271] and the
vulnerability analysis discussed in [RFC4272] also apply to this vulnerability analysis discussed in [RFC4272] also apply to this
document. document.
6. IANA Considerations 5. IANA Considerations
This document has no actions for IANA.
7. Contributors
The following people contributed to successful deployment of solution
described in this document:
Jakob Heitz
Cisco
Email: jheitz@cisco.com
Ondrej Filip
CZ.NIC
Email: ondrej.filip@nic.cz This document does not require any IANA actions.
8. References 6. References
8.1. Normative References 6.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
[RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A [RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
Border Gateway Protocol 4 (BGP-4)", RFC 4271, Border Gateway Protocol 4 (BGP-4)", RFC 4271,
DOI 10.17487/RFC4271, January 2006, DOI 10.17487/RFC4271, January 2006,
<http://www.rfc-editor.org/info/rfc4271>. <http://www.rfc-editor.org/info/rfc4271>.
8.2. Informative References [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <http://www.rfc-editor.org/info/rfc8174>.
6.2. Informative References
[RFC4272] Murphy, S., "BGP Security Vulnerabilities Analysis", [RFC4272] Murphy, S., "BGP Security Vulnerabilities Analysis",
RFC 4272, DOI 10.17487/RFC4272, January 2006, RFC 4272, DOI 10.17487/RFC4272, January 2006,
<http://www.rfc-editor.org/info/rfc4272>. <http://www.rfc-editor.org/info/rfc4272>.
[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, <http://www.rfc-editor.org/info/rfc7908>. 2016, <http://www.rfc-editor.org/info/rfc7908>.
Appendix A. Transition Considerations for BGP Implementers Appendix A. Transition Considerations for BGP Implementers
This appendix is non-normative. This appendix is not normative.
For an implementer, transitioning to a compliant BGP implementation For an implementer, transitioning to a compliant BGP implementation
may require a process that can take several years. may require a process that can take several years.
It is understood and acknowledged that operators who are taking It is understood and acknowledged that operators who are taking
advantage of an undefined behavior will always be surprised by advantage of an undefined behavior will always be surprised by
changes to said behavior. changes to said behavior.
A.1. "N+1 N+2" Release Strategy A.1. "N+1 N+2" Release Strategy
skipping to change at page 6, line 12 skipping to change at page 6, line 35
BGP implementation become aware that a configurable default exists in BGP implementation become aware that a configurable default exists in
the implementation, and can prepare accordingly. In release N+2 or the implementation, and can prepare accordingly. In release N+2 or
later, the inverse of the previous default configuration parameter later, the inverse of the previous default configuration parameter
that was introduced in release N+1 becomes the new default. that was introduced in release N+1 becomes the new default.
As a result, any new installation of release N+2 will adhere to this As a result, any new installation of release N+2 will adhere to this
document. Installations upgraded from version release N+1 will document. Installations upgraded from version release N+1 will
adhere to the previous insecure behavior, if no modification was made adhere to the previous insecure behavior, if no modification was made
to the "ebgp insecure-mode" configuration parameter. to the "ebgp insecure-mode" configuration parameter.
Acknowledgments
The authors would like to thank the following people for their
comments, support and review: Shane Amante, Christopher Morrow,
Robert Raszuk, Greg Skinner, Adam Chappell, Sriram Kotikalapudi,
Brian Dickson, Jeffrey Haas, John Heasley, Ignas Bagdonas, Donald
Smith, Alvaro Retana, John Scudder, and Dale Worley.
Contributors
The following people contributed to successful deployment of the
solution described in this document:
Jakob Heitz
Cisco
Email: jheitz@cisco.com
Ondrej Filip
CZ.NIC
Email: ondrej.filip@nic.cz
Authors' Addresses Authors' Addresses
Jared Mauch Jared Mauch
Akamai Technologies Akamai Technologies
8285 Reese Lane 8285 Reese Lane
Ann Arbor Michigan 48103 Ann Arbor Michigan 48103
US United States of America
Email: jared@akamai.com Email: jared@akamai.com
Job Snijders Job Snijders
NTT Communications NTT Communications
Theodorus Majofskistraat 100 Theodorus Majofskistraat 100
Amsterdam 1065 SZ Amsterdam 1065 SZ
NL The Netherlands
Email: job@ntt.net Email: job@ntt.net
Greg Hankins Greg Hankins
Nokia Nokia
777 E. Middlefield Road 777 E. Middlefield Road
Mountain View, CA 94043 Mountain View, CA 94043
USA United States of America
Email: greg.hankins@nokia.com Email: greg.hankins@nokia.com
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