Internet Draft Ruchi Kapoor Expires: January 2006 Gargi Nalawade Chandra Appanna Cisco Systems BGPv4 SAFI-Specific Attribute draft-kapoor-nalawade-idr-bgp-ssa-01.txt 1. 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. 2. Copyright Notice Copyright (C) The Internet Society (2005). 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 AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR draft-kapoor-nalawade-idr-bgp-ssa-01.txt [Page 1] Internet Draft - 2 - July 2005 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. 3. Abstract This document defines a new BGP attribute called the SAFI-Specific Attribute. The document also makes the attribute specific to be used by the Tunnel SAFI. The Tunnel-SAFI Specific attribute (also know as the Tunnel Attribute) is used to send out attributes of a Tunnel used by routing for different routing applications. This Tunnel attribute can contain various 'Types', where the Type identifies what kind of Tunnel the TLV describes. 4. Introduction This document defines a new BGP attribute called the Tunnel Attribute. The value part of the Tunnel Attribute can contain one or more an attribute, which can carry Tunnel Attributes for one or more Tunnel types originating on a given router. Also, unlike the fixed length (8 octets) extended community types, the SAFI-Specific Attribute TLV is a variable length entity, so it can carry data of any length, as required by the specific type of a SAFI-Specific Attribute TLV. 5. Format of the SAFI-Specific Attribute The format of the BGP SAFI-Specific attribute will be as follows: | Attr. Flags | Attr.Type Code| 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |1|1|0|?|UNUSED | Type = TBD | Length (2 Octets) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | Attribute Value | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ draft-kapoor-nalawade-idr-bgp-ssa-01.txt [Page 2] Internet Draft - 3 - July 2005 The BGP Tunnel is a variable length, optional transitive attribute. The Value field of the attribute may contain one or more SAFI- Speceific Attribute TLVs. The Value field of the Tunnel Attribute is encoded as follows and may contain one or more tuples of the following: - Type Field : 2 octets - Length Field: 2 octets - Value Field : Variable 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Value | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type Field: The format of the Type Field is as shown below: 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |T| | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ T - Transitive bit Value 1: The Tunnel type is transitive across ASes Value 0: The Tunnel type is non-transitive across ASes Remaining 15 bits: Indicate the type of the TLV. Length Field: The Length is 2 octets long and indicates the length of the Value field. The value contained in this Length field MUST not exceed the total length of the BGP Tunnel Attribute minus the total length of any prior TLVs. Value Field: The Value Field contains a TLV where the Types of the TLV are defined by the respective SAFIs. The TLV in the Value field of this Attribute will be of the form : draft-kapoor-nalawade-idr-bgp-ssa-01.txt [Page 3] Internet Draft - 4 - July 2005 - Type Field : 2 octets - Length Field: 2 octets - Value Field : Variable The Value field will have a fixed part as specified by the respective Tunnel Types and may have a variable part in the form of Sub-TLVs encoded as follows : - Sub-Type Field : 1 octets - Length Field: 1 octets - Value Field : Variable 6. Operation A BGP speaker that supports a SAFI, MUST accept any SAFI-Specific Attribute TLVs that are part of the SAFI. If the SAFI-Specific Attribute TLV is transitive, the BGP speaker MUST forward it even if it does not understand it. Operation rules are governed by those for the SAFI. This attribute only requires that it be forwarded even when it is not understood. When sending an UPDATE message for this SAFI to a peer, a BGP speaker MUST only advertise the SAFI-Specific Attribute TLVs that are defined and are valid for that SAFI. A Capability has not been defined for this attribute intentionally. For newer SAFIs, it is concieved that presence of the SAFI could imply understanding the SAFI-Specific Attribute and the SAFI- Specific Attribute TLVs. For existing SAFIs, a capbility may be required. 7. Security Considerations This extension to BGP does not change the underlying security issues. 8. Acknowledgements We would like to thank Dan Tappan and Jim Guichard for their significant contributions. We would also like to thank Francois LeFaucher, Arjun Sreekantiah, Shyam Suri and John Scudder for their comments and suggestions. 9. Normative References draft-kapoor-nalawade-idr-bgp-ssa-01.txt [Page 4] Internet Draft - 5 - July 2005 [BGP-4] Rekhter, Y. and T. Li (editors), "A Border Gateway Protocol 4 (BGP-4)", Internet Draft draft-ietf-idr-bgp4-26.txt, April 2005. [BGP-CAP] Chandra, R., Scudder, J., "Capabilities Advertisement with BGP-4", draft-ietf-idr-rfc2842bis-02.txt, April 2002. [IANA-AFI] http://www.iana.org/assignments/address-family-numbers. [IANA-SAFI] http://www.iana.org/assignments/safi-namespace. 10. Author's Addresses Ruchi Kapoor mailto:ruchi@cisco.com Gargi Nalawade mailto:gargi@cisco.com Chandra Appanna mailto: achandra@cisco.com Cisco Systems, Inc 170 West Tasman Drive San Jose, CA 95134 11. Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementors or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights which may cover technology that may be required to practice this standard. Please address the information to the IETF Executive Director. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary draft-kapoor-nalawade-idr-bgp-ssa-01.txt [Page 5] Internet Draft - 6 - July 2005 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. 12. Full Copyright Statement Copyright (C) The Internet Society (2005). All Rights Reserved. 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 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. 13. Expiration Date This memo is filed as expires January, 2006. draft-kapoor-nalawade-idr-bgp-ssa-01.txt [Page 6]