--- 1/draft-ietf-opsec-blackhole-urpf-01.txt 2009-03-08 12:12:04.000000000 +0100 +++ 2/draft-ietf-opsec-blackhole-urpf-02.txt 2009-03-08 12:12:04.000000000 +0100 @@ -1,20 +1,20 @@ Opsec Working Group W. Kumari Internet Draft Google - D. McPherson + D. McPherson Category: Informational Arbor Networks -Expires: September 5, 2009 - March 5, 2009 +Expires: September 7, 2009 + March 7, 2009 Remote Triggered Black Hole filtering with uRPF - + Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. @@ -31,25 +31,24 @@ http://www.ietf.org/shadow.html. This Internet-Draft will expire on September 5, 2009. Copyright Notice Copyright (c) 2009 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal - Provisions Relating to IETF Documents - (http://trustee.ietf.org/license-info) in effect on the date of - publication of this document. Please review these documents - carefully, as they describe your rights and restrictions with respect - to this document. + Provisions Relating to IETF Documents in effect on the date of + publication of this document (http://trustee.ietf.org/license-info). + Please review these documents carefully, as they describe your rights + and restrictions with respect to this document. Abstract Remote Triggered Black Hole (RTBH) filtering is a popular and effective technique for the mitigation of denial-of-service attacks. This document expands upon destination-based RTBH filtering by outlining a method to enable filtering by source address as well. Table of Contents @@ -68,23 +67,23 @@ C. A brief history of RTBH.........................................12 1. Introduction This document expands upon the technique outlined in "Configuring BGP to Block Denial-of-Service Attacks" [RFC3882] to demonstrate a method that allows for filtering by source address(es). 1.2 Terminology - The key words "MUST", "MUST NOT", "SHOULD", "SHOULD NOT", and "MAY" - in this document are to be interpreted as described in BCP 14, RFC - 2119 [RFC2119]. + 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]. 2. Background Network operators have developed a variety of techniques for mitigating denial of service attacks. While different techniques have varying strengths and weaknesses, from an implementation perspective the selection of which method to use for each type of attack involves evaluating the tradeoffs associated with each method. A common DoS attack directed against a customer of a service provider @@ -370,35 +369,28 @@ [RFC1918] Rekhter, Y., Moskowitz, B., Karrenberg, D., de Groot, G., and E. Lear, "Address Allocation for Private Internets", BCP 5, RFC 1918, February 1996. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3330] IANA, "Special-Use IPv4 Addresses", RFC 3330, September 2002. - [RFC4360] Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended - Communities Attribute", RFC 4360, February 2006. - [RFC3704] Baker, F. and P. Savola, "Ingress Filtering for Multihomed Networks", BCP 84, RFC 3704, March 2004. [RFC3882] Turk, D., "Configuring BGP to Block Denial-of-Service Attacks", RFC 3882, September 2004. 8.2. Informative References - [2223BIS] Reynolds, J. and R. Braden, "Instructions to Request for - Comments (RFC) Authors", draft-rfc-editor- - rfc2223bis-08.txt, August 2004. - [Greene2001] Greene Barry Raveendran and Jarvis Neil "Unicast Reverse Path Forwarding (uRPF) Enhancements for the ISP-ISP Edge", [ftp://ftp- eng.cisco.com/cons/isp/documents/uRPF_Enhancement.pdf], 2001. Appendix A: Cisco Router Configuration Sample This section provides a partial configuration for configuring RTBH on a Cisco router. This is not a complete configuration and should be @@ -589,25 +581,23 @@ To clarify and restate, uRPF Loose Check was created as one part of a rapid reaction tool to DDOS attacks that "drop packets based on source IP address that can be pushed out to over 60 routers with in 60 seconds, be longer than a thousand lines, be modified on the fly, and work in all your platforms filtering at line rate." The secondary benefits of using uRPF Loose Check for other functions is a secondary benefit - not the primary goal for its creation. To facilitate the adoption to the industry, uRPF Loose Check was not - patent. It was publicly published and disclosed in "Unicast Reverse - Path Forwarding (uRPF) Enhancements for the ISP-ISP Edge "Remote - Triggering Black Hole Filtering," by Barry Raveendran Greene and Neil - Jarvis [ftp://ftp- - eng.cisco.com/cons/isp/documents/uRPF_Enhancement.pdf]. + patented. It was publicly published and disclosed in "Unicast Reverse + Path Forwarding (uRPF) Enhancements for the ISP-ISP Edge" + [Greene2001]. Authors' Addresses Warren Kumari Google 1600 Amphitheatre Parkway Mountain View, CA 94043 Email: warren@kumari.net Danny McPherson