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
	skipping to change at page 1, line 48 ¶		skipping to change at page 1, line 48 ¶
	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
	skipping to change at page 2, line 28 ¶		skipping to change at page 2, line 28 ¶
	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].
	skipping to change at page 4, line 20 ¶		skipping to change at page 4, line 20 ¶
	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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