draft-ietf-grow-bgp-reject-05.txt   draft-ietf-grow-bgp-reject-06.txt 
Global Routing Operations J. Mauch Global Routing Operations J. Mauch
Internet-Draft Akamai Internet-Draft Akamai
Intended status: Standards Track J. Snijders Updates: 4271 (if approved) J. Snijders
Expires: October 12, 2017 NTT Intended status: Standards Track NTT
G. Hankins Expires: November 1, 2017 G. Hankins
Nokia Nokia
April 10, 2017 April 30, 2017
Default EBGP Route Propagation Behavior Without Policies Default EBGP Route Propagation Behavior Without Policies
draft-ietf-grow-bgp-reject-05 draft-ietf-grow-bgp-reject-06
Abstract Abstract
This document defines the default behavior of a BGP speaker when This document updates RFC4271 by defining the default behavior of a
there is no import or export policy associated with an External BGP BGP speaker when there is no Import or Export Policy associated with
session. an External BGP session.
Requirements Language Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. 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 Internet-Draft is submitted in full conformance with the
skipping to change at page 1, line 41 skipping to change at page 1, line 41
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 October 12, 2017. This Internet-Draft will expire on November 1, 2017.
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
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
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. Solution . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 3 3. Solution Specification . . . . . . . . . . . . . . . . . . . 3
4. Security Considerations . . . . . . . . . . . . . . . . . . . 3 4. Changes to RFC4271 . . . . . . . . . . . . . . . . . . . . . 3
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3 5. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 4
6. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 3 6. Security Considerations . . . . . . . . . . . . . . . . . . . 4
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 4 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
7.1. Normative References . . . . . . . . . . . . . . . . . . 4 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 4
7.2. Informative References . . . . . . . . . . . . . . . . . 4 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 4 9.1. Normative References . . . . . . . . . . . . . . . . . . 5
9.2. Informative References . . . . . . . . . . . . . . . . . 5
Appendix A. Transition Considerations . . . . . . . . . . . . . 5
A.1. N+1 N+2 Release Strategy . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction 1. Introduction
There are BGP routing security issues that need to be addressed to BGP routing security issues need to be addressed in order to make the
make the Internet more stable. Route leaks [RFC7908] are part of the Internet more stable. Route leaks [RFC7908] are part of the problem,
problem, but software defects or operator misconfigurations can but software defects or operator misconfiguration can contribute too.
contribute too. This document provides guidance to BGP [RFC4271] This document updates [RFC4271] in order to improve the default level
implementers to improve the default level of Internet routing of Internet routing security.
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 a BGP import and export policy for any explicit configuration of a BGP Import and Export Policy 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. When this confederation boundaries for all enabled address families. When this
solution is implemented, BGP speakers do not accept or send routes solution is implemented, BGP speakers do not use or send routes
without policies configured on EBGP sessions. without policies configured on EBGP sessions.
2. Solution 2. Terminology
The following requirements apply to all BGP speakers: [RFC4271] describes a Policy Information Base (PIB) which contains
local policies that can be applied to the information in the Routing
Information Base (RIB). This document distinguishes the type of
policy based on its application.
Import Policy: a local policy to be applied to the information
contained in the Adj-RIBs-In. As described in Section 3.2 [RFC4271],
the Adj-RIBs-In contain information learned from other BGP speakers,
and the application of the Import Policy results in the routes that
will be considered in the Decision Process by the local BGP speaker.
Export Policy: a local policy to be applied in selecting the
information contained in the Adj-RIBs-Out. As described in
Section 3.2 [RFC4271], the Adj-RIBs-Out contain information that has
been selected for advertisement to other BGP speakers.
3. Solution Specification
o A BGP speaker MUST consider any routes advertised by an EBGP peer o A BGP speaker MUST consider any routes advertised by an EBGP peer
ineligible for route selection (section 9.1.1 [RFC4271]), if no ineligible for route selection (section 9.1.1 [RFC4271]), if no
import policy was configured for the peer. Import Policy was configured for the peer.
o A BGP speaker MUST NOT advertise any routes to an EBGP peer, if no o A BGP speaker MUST NOT advertise any routes to an EBGP peer, if no
export policy was configured for the peer. Export Policy was configured for the peer.
o A BGP speaker SHOULD fall back to an "import nothing" and "export
nothing" mode following failure of internal components, such as a
policy engine.
o A BGP speaker MAY provide a configuration option to disable the o A BGP speaker MAY provide a configuration option to disable the
preceding behaviors, but it MUST implement them by default. preceding behaviors.
3. Acknowledgments 4. Changes to RFC4271
This section describes the Updates to [RFC4271] that define the
default behavior of a BGP speaker when there are no Import or Export
Policies associated with a particular EBGP session.
The following paragraph is added to Section 9.1 (Decision Process)
after the fifth paragraph ending in "route aggregation and route
information reduction":
Routes contained in an Adj-RIB-In associated with an EBGP peer
SHALL NOT be considered eligible in the Decision Process if no
explicit Import Policy has been applied.
The following paragraph is added to Section 9.1.3 (Phase 3: Route
Dissemination) after the third paragraph ending in "by means of an
UPDATE message (see 9.2).":
Routes SHALL NOT be added to an Adj-RIB-Out associated with an
EBGP peer if no explicit Export Policy has been applied.
5. Acknowledgments
The authors would like to thank the following people for their The authors would like to thank the following people for their
comments, support and review: Shane Amante, Christopher Morrow, comments, support and review: Shane Amante, Christopher Morrow,
Robert Raszuk, Greg Skinner, Adam Chappell, Sriram Kotikalapudi, Robert Raszuk, Greg Skinner, Adam Chappell, Sriram Kotikalapudi,
Brian Dickson, Jeffrey Haas, John Heasley, Ignas Bagdonas, Donald Brian Dickson, Jeffrey Haas, John Heasley, Ignas Bagdonas, Donald
Smith, and Dale Worley. Smith, Dale Worley, and Alvaro Retana.
4. Security Considerations 6. Security Considerations
This document addresses a basic routing security issue caused by Permissive default routing policies can result in inadvertent effects
permissive default routing policy configurations. Operators need such as route leaks [RFC7908], in general resulting in rerouting of
implementers to address this problem with more secure defaults to traffic through an unexpected path. While it is possible for an
mitigate collateral damage on Internet routing. Inadvertent or operator to use monitoring to detect unexpected flows, there is no
adversarial advertisements cause business impact that can be general framework that can be applied. These policies also have the
mitigated by a secure default behavior. potential to expose software defects or misconfiguration that could
have unforeseen technical and business impacting effects.
5. IANA Considerations The update to [RFC4271] specified in this document is intended to
eliminate those inadvertent effects. Operators must explicitly
configure Import and Export Policies to achieve their expected goals.
There is of course no protection against a malicious or incorrect
explicit configuration.
The security considerations described in [RFC4271] and the
vulnerability analysis discussed in [RFC4272] also apply to this
document.
7. IANA Considerations
This document has no actions for IANA. This document has no actions for IANA.
6. Contributors 8. Contributors
The following people contributed to successful deployment of solution The following people contributed to successful deployment of solution
described in this document: described in this document:
Jakob Heitz Jakob Heitz
Cisco Cisco
Email: jheitz@cisco.com Email: jheitz@cisco.com
Ondrej Filip Ondrej Filip
CZ.NIC CZ.NIC
Email: ondrej.filip@nic.cz Email: ondrej.filip@nic.cz
7. References 9. References
7.1. Normative References 9.1. 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>.
7.2. Informative References 9.2. Informative References
[RFC4272] Murphy, S., "BGP Security Vulnerabilities Analysis",
RFC 4272, DOI 10.17487/RFC4272, January 2006,
<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
This appendix is non-normative.
It is anticipated that transitioning from an acquiescent BGP
implementation to a compliant BGP implementation will require a
process thay may take several years.
It is understood and acknowledged that operators who are taking
advantage of an undefined behavior will always be surprised by
changes to said behavior.
A.1. N+1 N+2 Release Strategy
An implementer could leverage an approach described as "the N+1 and
N+2 release strategy". In release N+1, the implementer introduces a
new default configuration parameter to indicate that the BGP speaker
is operating in "ebgp insecure-mode". In addition to the
introduction of the new parameter, an implementer could begin to
display informational warnings to the operator that certain parts of
the configuration are incomplete. In release N+1, operators of the
BGP implementation become aware that a configurable default exists in
the implementation, and can prepare accordingly. In release N+2 or
later, the inverse of the previous default configuration parameter
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
document. Installations upgraded from version release N+1 will
adhere to the previous insecure behavior, if no modification was made
to the "ebgp insecure-mode" configuration parameter.
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 US
Email: jared@akamai.com Email: jared@akamai.com
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