Network Working Group R. White Internet-Draft Cisco Systems Expires: August 1, 2008 J. Burns Wachovia January 29, 2008 Common Practices in Routing Protocols Deployment draft-white-rppract-00 Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of 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. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on August 1, 2008. Copyright Notice Copyright (C) The IETF Trust (2008). Abstract This document discusses common practices used in deploying routing protocols in both public and private networks. The focus is not to describe how routing protocols should be deployed, but rather how they are generally deployed, to provide those working on specifications which impact the operation of routing protocols with guidance in what will likely be deployed, or what will likely not be deployed. The focus in thie document will be ionterdomain routing, White & Burns Expires August 1, 2008 [Page 1] Internet-Draft RP Common Practices January 2008 but it will cover aspects of intradomain routing, as well. 1. Background When considering new extensions to existing routing protocols, it's useful to consider them in the context of existing usage of these protocols. Various questions come to mind, such as: o The way in which routing information is originated into the routing protocol. o The way in which routing information is aggregated within the network. o The way in which routing protocol peering sessions are configured o The types of security which are enabled at different places within the network. o .... Each of these topics will be covered in a separate section below. 10.1.1.0/24--(AS65000)---(AS65001)--(AS65002) 2. Originating Routing Information Interior and exterior gateway protocols have a number of ways in which they classify routing information, the primary of which is the way in which destinations have been injected into the protocol. 2.1. Interior Gateway Protocols For interior gateway protocols, routing information is normally classified as originating either from within the protocol, or from a source which is external to the protocol. Destinations which are learned of through a direct connection, such as a connection to a subnet on a router running the protocol, are called internal routes. Destinations which are learned of through some other means, outside the protocol, are called external routes. Virtually all routing information is injected into interior gateway protocols as internal routing information, unless there is a specific reason for injecting external information into the IGP routing domain. Some specific reasons might include: When multiple routing protocols are being used in the same network. Generally, this occurs when two networks are merged, or when a part of the network runs a different routing protocol for policy or design reasons. White & Burns Expires August 1, 2008 [Page 2] Internet-Draft RP Common Practices January 2008 When interaction is occuring with a network not under the local administrator's control. Generally, injecting external live routing information between interior gateway protocols between routing domains is not encouraged, but there are instances when this occurs. To inject manually configured reachability information into the protocol. This generally occurs along the edges of a network, to provide reachability to destinations not within the network itself. To provide reachability across some form of layer 3 virtual private network, when no mechanism is deployed or supported to provide the transport of native routing information across the VPN. Generally, injectiong of external routing information is avoided where possible in network designs, unless there is a specific policy or design related reason to do so. 2.2. Exterior Gateway Protocols For exterior gateway protocols, the distinction between internal and external routing information is blurred, as all information is considered to be external. There is an indicator of where a specific piece of routing information originated, but this information is used very low on the decision process. 3. Aggregating Routing Information 4. Common Practices In Peering 5. Common Practices in Security 6. Summary .... 7. Acknowledgements .... White & Burns Expires August 1, 2008 [Page 3] Internet-Draft RP Common Practices January 2008 8. Informative References [BGP-MD5] Heffernan, A., "Protection of BGP Sessions via the TCP MD5 Signature Option", RFC 2385, August 1998. [RFC4271] Rekhter, Y., Li, T., and S. Hares, "A Border Gateway Protocol 4 (BGP-4)", RFC 4271, January 2006. Authors' Addresses Russ White Cisco Systems Phone: Fax: Email: riw@cisco.com URI: John Burns Wachovia Phone: Fax: Email: john.burns1@wachovia.com URI: White & Burns Expires August 1, 2008 [Page 4] Internet-Draft RP Common Practices January 2008 Full Copyright Statement Copyright (C) The IETF Trust (2008). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 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The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Acknowledgment Funding for the RFC Editor function is provided by the IETF Administrative Support Activity (IASA). White & Burns Expires August 1, 2008 [Page 5]