draft-ietf-grow-blackholing-01.txt   draft-ietf-grow-blackholing-02.txt 
Network Working Group T. King Network Working Group T. King
Internet-Draft C. Dietzel Internet-Draft C. Dietzel
Intended status: Standards Track DE-CIX Management GmbH Intended status: Informational DE-CIX Management GmbH
Expires: December 31, 2016 J. Snijders Expires: January 2, 2017 J. Snijders
NTT NTT
G. Doering G. Doering
SpaceNet AG SpaceNet AG
G. Hankins G. Hankins
Nokia Nokia
June 29, 2016 July 1, 2016
BLACKHOLE BGP Community for Blackholing BLACKHOLE BGP Community for Blackholing
draft-ietf-grow-blackholing-01 draft-ietf-grow-blackholing-02
Abstract Abstract
This document describes the use of a well-known Border Gateway This document describes the use of a well-known Border Gateway
Protocol (BGP) community for blackholing in IP networks. This well- Protocol (BGP) community for destination based blackholing in IP
known advisory transitive BGP community, namely BLACKHOLE, allows an networks. This well-known advisory transitive BGP community, namely
origin AS to specify that a neighboring network should blackhole a BLACKHOLE, allows an origin AS to specify that a neighboring network
specific IP prefix. should discard any traffic destined towards the tagged IP prefix.
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" are to "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" are to
be interpreted as described in [RFC2119] only when they appear in all be interpreted as described in [RFC2119] only when they appear in all
upper case. They may also appear in lower or mixed case as English upper case. They may also appear in lower or mixed case as English
words, without normative meaning. words, without normative meaning.
Status of This Memo Status of This Memo
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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 December 31, 2016. This Internet-Draft will expire on January 2, 2017.
Copyright Notice Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the Copyright (c) 2016 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
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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. BLACKHOLE Attribute . . . . . . . . . . . . . . . . . . . . . 3 2. BLACKHOLE Attribute . . . . . . . . . . . . . . . . . . . . . 3
3. Operational Recommendations . . . . . . . . . . . . . . . . . 3 3. Operational Recommendations . . . . . . . . . . . . . . . . . 3
3.1. IP Prefix Announcements with BLACKHOLE Community Attached 3 3.1. IP Prefix Announcements with BLACKHOLE Community Attached 3
3.2. Local Scope of Blackholes . . . . . . . . . . . . . . . . 3 3.2. Local Scope of Blackholes . . . . . . . . . . . . . . . . 3
3.3. Accepting Blackholed IP Prefixes . . . . . . . . . . . . 4 3.3. Accepting Blackholed IP Prefixes . . . . . . . . . . . . 4
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 4. Vendor Implementation Recommendations . . . . . . . . . . . . 4
5. Security Considerations . . . . . . . . . . . . . . . . . . . 4 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 6. Security Considerations . . . . . . . . . . . . . . . . . . . 4
6.1. Normative References . . . . . . . . . . . . . . . . . . 5 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
6.2. Informative References . . . . . . . . . . . . . . . . . 5 7.1. Normative References . . . . . . . . . . . . . . . . . . 5
7.2. Informative References . . . . . . . . . . . . . . . . . 5
Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 6 Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction 1. Introduction
Network infrastructures have been increasingly hampered by DDoS Network infrastructures have been increasingly hampered by DDoS
attacks. In order to dampen the effects of these DDoS attacks, IP attacks. In order to dampen the effects of these DDoS attacks, IP
networks have offered BGP blackholing to neighboring networks via networks have offered BGP blackholing to neighboring networks via
various mechanisms such as described in [RFC3882] and [RFC5635]. various mechanisms such as described in [RFC3882] and [RFC5635].
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should be as small as possible in order to limit the impact of should be as small as possible in order to limit the impact of
discarding traffic for adjacent IP space that is not under DDoS discarding traffic for adjacent IP space that is not under DDoS
duress. Typically, the blackhole route's prefix length is as duress. Typically, the blackhole route's prefix length is as
specific as /32 for IPv4 and /128 for IPv6. specific as /32 for IPv4 and /128 for IPv6.
BGP speakers SHOULD only accept and honor BGP announcements carrying BGP speakers SHOULD only accept and honor BGP announcements carrying
the BLACKHOLE community if the announced prefix is covered by a the BLACKHOLE community if the announced prefix is covered by a
shorter prefix for which the neighboring network is authorized to shorter prefix for which the neighboring network is authorized to
advertise. advertise.
4. IANA Considerations 4. Vendor Implementation Recommendations
Without an explicit configuration directive set by the operator,
network elements SHOULD NOT discard traffic destined towards IP
prefixes which are tagged with the BLACKHOLE BGP community. The
operator is expected to explicitly configure the network element to
honor the BLACKHOLE BGP community in a way that is compliant with the
operator's routing policy.
Vendors MAY provide a short-hand keyword in their configuration
language to reference the well-known BLACKHOLE BGP community
attribute value. The suggested string to be used is "blackhole".
5. IANA Considerations
The IANA is requested to register BLACKHOLE as a well-known BGP The IANA is requested to register BLACKHOLE as a well-known BGP
community with global significance: community with global significance:
BLACKHOLE (= 0xFFFF029A) BLACKHOLE (= 0xFFFF029A)
The low-order two octets in decimal are 666, amongst network The low-order two octets in decimal are 666, amongst network
operators a value commonly associated with BGP blackholing. operators a value commonly associated with BGP blackholing.
5. Security Considerations 6. Security Considerations
BGP contains no specific mechanism to prevent the unauthorized BGP contains no specific mechanism to prevent the unauthorized
modification of information by the forwarding agent. This allows modification of information by the forwarding agent. This allows
routing information to be modified, removed, or false information to routing information to be modified, removed, or false information to
be added by forwarding agents. Recipients of routing information are be added by forwarding agents. Recipients of routing information are
not able to detect this modification. Also, RPKI [RFC6810] and not able to detect this modification. Also, RPKI [RFC6810] and
BGPSec [I-D.ietf-sidr-bgpsec-overview] do not fully resolve this BGPSec [I-D.ietf-sidr-bgpsec-overview] do not fully resolve this
situation. For instance, BGP communities can still be added or situation. For instance, BGP communities can still be added or
altered by a forwarding agent even if RPKI and BGPSec are in place. altered by a forwarding agent even if RPKI and BGPSec are in place.
The BLACKHOLE BGP community does not alter this situation.
A new additional attack vector is introduced into BGP by using the
BLACKHOLE BGP community: denial of service attacks for IP prefixes.
The unauthorized addition of the BLACKHOLE BGP community to an IP The unauthorized addition of the BLACKHOLE BGP community to an IP
prefix by a forwarding agent may cause a denial of service attack prefix by an adversery may cause a denial of service attack based on
based on denial of reachability. The denial of service will happen denial of reachability.
if a network offering blackholing is traversed. However, denial of
service attack vectors to BGP are not new as the injection of false
routing information is already possible.
In order to further limit the impact of unauthorized BGP In order to further limit the impact of unauthorized BGP
announcements carrying the BLACKHOLE BGP community, the receiving BGP announcements carrying the BLACKHOLE BGP community, the receiving BGP
speaker SHOULD verify by applying strict filtering (see section speaker SHOULD verify by applying strict filtering (see section
6.2.1.1.2. [RFC7454]) that the peer announcing the prefix is 6.2.1.1.2. [RFC7454]) that the peer announcing the prefix is
authorized to do so. If not, the BGP announcement should be filtered authorized to do so. If not, the BGP announcement should be filtered
out. out.
The presence of this BLACKHOLE BGP community may introduce a resource 7. References
exhaustion attack to BGP speakers. If a BGP speaker receives many IP
prefixes containing the BLACKHOLE BGP community, its internal
resources such as CPU power, memory or FIB capacity might exhaust,
especially if usual prefix sanity checks (e.g. such as IP prefix
length or number of prefixes) are disabled (see Section 3.3).
6. References
6.1. Normative References 7.1. Normative References
[RFC1997] Chandra, R., Traina, P., and T. Li, "BGP Communities [RFC1997] Chandra, R., Traina, P., and T. Li, "BGP Communities
Attribute", RFC 1997, DOI 10.17487/RFC1997, August 1996, Attribute", RFC 1997, DOI 10.17487/RFC1997, August 1996,
<http://www.rfc-editor.org/info/rfc1997>. <http://www.rfc-editor.org/info/rfc1997>.
[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, DOI 10.17487/ Requirement Levels", BCP 14, RFC 2119,
RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
6.2. Informative References 7.2. Informative References
[I-D.ietf-sidr-bgpsec-overview] [I-D.ietf-sidr-bgpsec-overview]
Lepinski, M. and S. Turner, "An Overview of BGPsec", Lepinski, M. and S. Turner, "An Overview of BGPsec",
draft-ietf-sidr-bgpsec-overview-08 (work in progress), draft-ietf-sidr-bgpsec-overview-08 (work in progress),
June 2016. June 2016.
[RFC3882] Turk, D., "Configuring BGP to Block Denial-of-Service [RFC3882] Turk, D., "Configuring BGP to Block Denial-of-Service
Attacks", RFC 3882, DOI 10.17487/RFC3882, September 2004, Attacks", RFC 3882, DOI 10.17487/RFC3882, September 2004,
<http://www.rfc-editor.org/info/rfc3882>. <http://www.rfc-editor.org/info/rfc3882>.
[RFC5635] Kumari, W. and D. McPherson, "Remote Triggered Black Hole [RFC5635] Kumari, W. and D. McPherson, "Remote Triggered Black Hole
Filtering with Unicast Reverse Path Forwarding (uRPF)", Filtering with Unicast Reverse Path Forwarding (uRPF)",
RFC 5635, DOI 10.17487/RFC5635, August 2009, RFC 5635, DOI 10.17487/RFC5635, August 2009,
<http://www.rfc-editor.org/info/rfc5635>. <http://www.rfc-editor.org/info/rfc5635>.
[RFC6810] Bush, R. and R. Austein, "The Resource Public Key [RFC6810] Bush, R. and R. Austein, "The Resource Public Key
Infrastructure (RPKI) to Router Protocol", RFC 6810, DOI Infrastructure (RPKI) to Router Protocol", RFC 6810,
10.17487/RFC6810, January 2013, DOI 10.17487/RFC6810, January 2013,
<http://www.rfc-editor.org/info/rfc6810>. <http://www.rfc-editor.org/info/rfc6810>.
[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>.
Appendix A. Acknowledgements Appendix A. Acknowledgements
The authors would like to gratefully acknowledge many people who have The authors would like to gratefully acknowledge many people who have
contributed discussions and ideas to the making of this proposal. contributed discussions and ideas to the making of this proposal.
They include Petr Jiran, Yordan Kritski, Christian Seitz, Nick They include Petr Jiran, Yordan Kritski, Christian Seitz, Nick
Hilliard, Joel Jaeggli, Christopher Morrow, Thomas Mangin, Will Hilliard, Joel Jaeggli, Christopher Morrow, Thomas Mangin, Will
Hargrave and Niels Bakker. Hargrave, Niels Bakker and David Farmer.
Authors' Addresses Authors' Addresses
Thomas King Thomas King
DE-CIX Management GmbH DE-CIX Management GmbH
Lichtstrasse 43i Lichtstrasse 43i
Cologne 50825 Cologne 50825
Germany Germany
Email: thomas.king@de-cix.net Email: thomas.king@de-cix.net
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