draft-ietf-grow-no-more-unallocated-slash8s-04.txt		rfc6441.txt
	Network Working Group L. Vegoda		Internet Engineering Task Force (IETF) L. Vegoda
	Internet-Draft ICANN		Request for Comments: 6441 ICANN
	Intended status: BCP October 12, 2011		BCP: 171 November 2011
	Expires: April 14, 2012		Category: Best Current Practice
			ISSN: 2070-1721
	Time to Remove Filters for Previously Unallocated IPv4 /8s		Time to Remove Filters for Previously Unallocated IPv4 /8s
	draft-ietf-grow-no-more-unallocated-slash8s-04
	Abstract		Abstract
	It has been common for network administrators to filter IP traffic		It has been common for network administrators to filter IP traffic
	from and BGP prefixes of unallocated IPv4 address space. Now that		from and BGP prefixes of unallocated IPv4 address space. Now that
	there are no longer any unallocated IPv4 /8s, this practise is more		there are no longer any unallocated IPv4 /8s, this practise is more
	complicated, fragile and expensive. Network administrators are		complicated, fragile, and expensive. Network administrators are
	advised to remove filters based on the registration status of the		advised to remove filters based on the registration status of the
	address space.		address space.
	This document explains why any remaining packet and BGP prefix		This document explains why any remaining packet and BGP prefix
	filters for unallocated IPv4 /8s should now be removed on border		filters for unallocated IPv4 /8s should now be removed on border
	routers and documents those IPv4 unicast prefixes that should not be		routers and documents those IPv4 unicast prefixes that should not be
	routed across the public Internet.		routed across the public Internet.
	Status of this Memo		Status of This Memo
	This Internet-Draft is submitted in full conformance with the
	provisions of BCP 78 and BCP 79.
	Internet-Drafts are working documents of the Internet Engineering		This memo documents an Internet Best Current Practice.
	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
			BCPs is available in Section 2 of RFC 5741.
	This Internet-Draft will expire on April 14, 2012.		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/rfc6441.
	Copyright Notice		Copyright Notice
	Copyright (c) 2011 IETF Trust and the persons identified as the		Copyright (c) 2011 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 . . . . . . . . . . . . . . . . . . . . . . . . . 3		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
	2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3		2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 2
	3. Traffic Filtering Options . . . . . . . . . . . . . . . . . . . 3		3. Traffic Filtering Options . . . . . . . . . . . . . . . . . . . 3
	3.1. No Longer Filtering Based on Address Registration		3.1. No Longer Filtering Based on Address Registration
	Status . . . . . . . . . . . . . . . . . . . . . . . . . . 3		Status . . . . . . . . . . . . . . . . . . . . . . . . . . 3
	3.2. Continuing to Filter Traffic from Unallocated IPv4		3.2. Continuing to Filter Traffic from Unallocated IPv4
	Space . . . . . . . . . . . . . . . . . . . . . . . . . . . 4		Space . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
	4. Prefixes That Should Not be Routed Across the Internet . . . . 4		4. Prefixes That Should Not be Routed across the Internet . . . . 3
	5. Security Considerations . . . . . . . . . . . . . . . . . . . . 5		5. Security Considerations . . . . . . . . . . . . . . . . . . . . 3
	6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5		6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 4
	7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5		6.1. Normative References . . . . . . . . . . . . . . . . . . . 4
	7.1. Normative References . . . . . . . . . . . . . . . . . . . 5		6.2. Informative References . . . . . . . . . . . . . . . . . . 4
	7.2. Informative References . . . . . . . . . . . . . . . . . . 5		Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . . 5
	Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . . 6
	Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 6
	1. Introduction		1. Introduction
	It has been common for network administrators to filter IP traffic		It has been common for network administrators to filter IP traffic
	from and BGP prefixes of unallocated IPv4 address space. Now that		from and BGP prefixes of unallocated IPv4 address space. Now that
	there are no longer any unallocated IPv4 /8s, this practise is more		there are no longer any unallocated IPv4 /8s, this practise is more
	complicated, fragile and expensive. Network administrators are		complicated, fragile, and expensive. Network administrators are
	advised to remove filters based on the registration status of the		advised to remove filters based on the registration status of the
	address space.		address space.
	This document explains why any remaining packet and BGP prefix		This document explains why any remaining packet and BGP prefix
	filters for unallocated IPv4 /8s should now be removed on border		filters for unallocated IPv4 /8s should now be removed on border
	routers and documents those IPv4 unicast prefixes that should not be		routers and documents those IPv4 unicast prefixes that should not be
	routed across the public Internet.		routed across the public Internet.
	2. Terminology		2. Terminology
	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 BCP 14, RFC 2119		document are to be interpreted as described in BCP 14, RFC 2119
	[RFC2119].		[RFC2119].
	Martians [RFC1208] is a humorous term applied to packets that turn up		Martians [RFC1208] is a humorous term applied to packets that turn up
	unexpectedly on the wrong network because of bogus routing entries.		unexpectedly on the wrong network because of bogus routing entries.
	It is also used as a name for a packet which has an altogether bogus		It is also used as a name for a packet that has an altogether bogus
	(non-registered or ill-formed) Internet address. Bogons [RFC3871]		(non-registered or ill-formed) Internet address. Bogons [RFC3871]
	are packets sourced from addresses that have not yet been allocated		are packets sourced from addresses that have not yet been allocated
	by IANA or the Regional Internet Registries (RIRs), or addresses		by IANA or the Regional Internet Registries (RIRs), or addresses
	reserved for private or special use by RFCs [RFC5735].Bogons are		reserved for private or special use by RFCs [RFC5735]. Bogons are
	referred to as "Dark IP" in some circles. .		referred to as "Dark IP" in some circles.
	3. Traffic Filtering Options		3. Traffic Filtering Options
	3.1. No Longer Filtering Based on Address Registration Status		3.1. No Longer Filtering Based on Address Registration Status
	Network administrators who implemented filters for unallocated IPv4		Network administrators who implemented filters for unallocated IPv4
	/8s did so in the knowledge that those /8s were not a legitimate		/8s did so in the knowledge that those /8s were not a legitimate
	source of traffic on the Internet and that there was a small number		source of traffic on the Internet and that there was a small number
	of bogon filters to implement. Now that there are no longer any		of bogon filters to implement. Now that there are no longer any
	unallocated unicast IPv4 /8s, there will be legitimate Internet		unallocated unicast IPv4 /8s, there will be legitimate Internet
	skipping to change at page 4, line 15		skipping to change at page 3, line 35
	3.2. Continuing to Filter Traffic from Unallocated IPv4 Space		3.2. Continuing to Filter Traffic from Unallocated IPv4 Space
	Some network administrators might want to continue filtering		Some network administrators might want to continue filtering
	unallocated IPv4 addresses managed by the RIRs. This requires		unallocated IPv4 addresses managed by the RIRs. This requires
	significantly more granular ingress filters and the highly dynamic		significantly more granular ingress filters and the highly dynamic
	nature of the RIRs' address pools means that filters need to be		nature of the RIRs' address pools means that filters need to be
	updated on a daily basis to avoid blocking legitimate incoming		updated on a daily basis to avoid blocking legitimate incoming
	traffic.		traffic.
	4. Prefixes That Should Not be Routed Across the Internet		4. Prefixes That Should Not be Routed across the Internet
	Network operators who only wish to filter traffic originating from
	addresses that should never be routed across the Internet, Martians,
	can deploy a set of packet and prefix filters designed to block
	traffic from address blocks reserved for special purposes. These
	are:
	- 0.0.0.0/8 (Local identification) [RFC1122];
	- 10.0.0.0/8 (Private use) [RFC1918];
	- 127.0.0.0/8 (Loopback) [RFC1122];
	- 169.254.0.0/16 (Link local) [RFC3927];
	- 172.16.0.0/12 (Private use) [RFC1918];
	- 192.0.2.0/24 (TEST-NET-1) [RFC5737];
	- 192.168.0.0/16 (Private use) [RFC1918];
	- 198.18.0.0/15 (Benchmark testing) [RFC2544];
	- 198.51.100.0/24 (TEST-NET-2) [RFC5737];
	- 203.0.113.0/24 (TEST-NET-3) [RFC5737];
	- 224.0.0.0/4 (Multicast) [RFC5771]; and
	- 240.0.0.0/4 (Future use) [RFC1112].
	A full set of special use IPv4 addresses can be found in [RFC5735].		Network operators may deploy filters that block traffic destined for
	It includes prefixes that are intended for Internet use.		Martian prefixes. Currently, the Martian prefix table is defined by
			[RFC5735] which reserves each Martian prefix for some specific,
			special use. If the Martian prefix table ever changes, that change
			will be documented in an RFC that either updates or obsoletes
			[RFC5735].
	5. Security Considerations		5. Security Considerations
	The cessation of filters based on unallocated IPv4 /8 allocations is		The cessation of filters based on unallocated IPv4 /8 allocations is
	an evolutionary step towards reasonable security filters. While		an evolutionary step towards reasonable security filters. While
	these filters are no longer necessary, and in fact harmful, this does		these filters are no longer necessary, and in fact harmful, this does
	not obviate the need to continue other security solutions. These		not obviate the need to continue other security solutions. These
	other solutions are as necessary today as they ever were.		other solutions are as necessary today as they ever were.
	6. IANA Considerations		6. References
	This document makes no request of IANA.
	7. References
	7.1. Normative References
	[RFC1112] Deering, S., "Host extensions for IP multicasting", STD 5,
	RFC 1112, August 1989.
	[RFC1122] Braden, R., "Requirements for Internet Hosts -
	Communication Layers", STD 3, RFC 1122, October 1989.
	[RFC1918] Rekhter, Y., Moskowitz, R., Karrenberg, D., Groot, G., and		6.1. Normative References
	E. Lear, "Address Allocation for Private Internets",
	BCP 5, RFC 1918, February 1996.
	[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, March 1997.		Requirement Levels", BCP 14, RFC 2119, March 1997.
	[RFC3927] Cheshire, S., Aboba, B., and E. Guttman, "Dynamic
	Configuration of IPv4 Link-Local Addresses", RFC 3927,
	May 2005.
	[RFC5735] Cotton, M. and L. Vegoda, "Special Use IPv4 Addresses",		[RFC5735] Cotton, M. and L. Vegoda, "Special Use IPv4 Addresses",
	BCP 153, RFC 5735, January 2010.		BCP 153, RFC 5735, January 2010.
	[RFC5771] Cotton, M., Vegoda, L., and D. Meyer, "IANA Guidelines for		6.2. Informative References
	IPv4 Multicast Address Assignments", BCP 51, RFC 5771,
	March 2010.
	7.2. Informative References
	[RFC1208] Jacobsen, O. and D. Lynch, "Glossary of networking terms",		[RFC1208] Jacobsen, O. and D. Lynch, "Glossary of networking terms",
	RFC 1208, March 1991.		RFC 1208, March 1991.
	[RFC2544] Bradner, S. and J. McQuaid, "Benchmarking Methodology for
	Network Interconnect Devices", RFC 2544, March 1999.
	[RFC3871] Jones, G., "Operational Security Requirements for Large		[RFC3871] Jones, G., "Operational Security Requirements for Large
	Internet Service Provider (ISP) IP Network		Internet Service Provider (ISP) IP Network
	Infrastructure", RFC 3871, September 2004.		Infrastructure", RFC 3871, September 2004.
	[RFC5737] Arkko, J., Cotton, M., and L. Vegoda, "IPv4 Address Blocks
	Reserved for Documentation", RFC 5737, January 2010.
	Appendix A. Acknowledgments		Appendix A. Acknowledgments
	Thanks are owed to Kim Davies, Terry Manderson, Dave Piscitello and		Thanks are owed to Kim Davies, Terry Manderson, Dave Piscitello, and
	Joe Abley for helpful advice on how to focus this document. Thanks		Joe Abley for helpful advice on how to focus this document. Thanks
	also go to Andy Davidson, Philip Smith and Rob Thomas for early		also go to Andy Davidson, Philip Smith, and Rob Thomas for early
	reviews and suggestions for improvements to the text and Carlos		reviews and suggestions for improvements to the text, and to Carlos
	Pignataro for his support and comments.		Pignataro for his support and comments.
	Author's Address		Author's Address
	Leo Vegoda		Leo Vegoda
	Internet Corporation for Assigned Names and Numbers		Internet Corporation for Assigned Names and Numbers
	4676 Admiralty Way, Suite 330		4676 Admiralty Way, Suite 330
	Marina del Rey, CA 90292		Marina del Rey, CA 90292
	United States of America		United States of America
	Phone: +1-310-823-9358		Phone: +1-310-823-9358
	Email: leo.vegoda@icann.org		EMail: leo.vegoda@icann.org
	URI: http://www.iana.org/		URI: http://www.iana.org/
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