Network Working Group Gargi Nalawade Internet Draft Arjun Sreekantiah Expires: August 2004 Cisco Systems MDT SAFI draft-nalawade-idr-mdt-safi-00.txt 1. Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. 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 (2001). All Rights Reserved. 3. Abstract There is a need for transporting MDT attributes within and across Autonomous Systems. This draft defines a new Address-Family that can be used to do the distribution. 4. Introduction Two end-points of a Multicast Tunnel need to know the end-point information and its binding to a network address and the MDT used for the respective VRF at the remote PE. Normally, Tunnel endpoint draft-nalawade-mdt-safi-00.txt [Page 1] Internet Draft draft-nalawade-idr-mdt-safi-00.txt August 2004 addresses can be statically configured. But in case of a large network with large number of VPNs where there may be a need for a large number of endpoints and a large number of VRFs, the amount of information that needs to be exchanged and maintained between PEs for Multicast Tunnels for VPNs, is quite large. It therefore needs a mechanism that can maintain and support Multicast Tunnel based VPNs in a flexible, scalable manner. Also, in inter-AS and inter-provider scenarios, this mechanism needs to be supported across autonomous systems and provider domains. 5. The MDT SAFI A new Subsequent-Address Family called the MDT SAFI is being defined. The NLRI for this SAFI, will contain the address of the nexthop which will be used by the multicast source PE to send the PIM Join for the default MDT address to. The NLRI format is 8-byte-RD:IPv4-address followed by the MDT group address. i.e. The MP_REACH attribute for this SAFI will contain one or more tuples of the following form : +------------------------------+ | | | RD:IPv4-address (12 octets) | | | +-------------------------------+ | MDT Group-address (4 octets) | +-------------------------------+ where : Route-Distinguisher : is the RD of the VRF to which this MDT attribute belongs. MDT Group Address : is the Group-address of the MDT-Group that a VRF is associated to. This can be variable length. But for IPV4 addresses - this will be 4 octets. 6. The Connector Attribute An Optional Transitive Connector attribute is being defined to link a draft-nalawade-mdt-safi-00.txt [Page 2] Internet Draft draft-nalawade-idr-mdt-safi-00.txt August 2004 BGP AFI/SAFI with another AFI/SAFI, so that the prefix of one AFI/SAFI could derive an information entity that is dependant on the NLRI advertised through another AFI/SAFI. An example of this is as illustrated in [MT-DISC]. The attribute contains one or more tuples of the form : +------------------------------+ | | | AFI (2 octets) | +------------------------------+ | SAFI (1 octets) | +------------------------------+ | | | Value (Variable) | | | +------------------------------+ where : AFI : is the value of the Address-family which needs the information carried in the value field of this attribute. SAFI : is the value of the Subsequent Address-family which needs the information carried in the value field of this attribute. Value : is a variable length field defined by the AFI/SAFI carried in this tuple, which would be used by the AFI/SAFI in this tuple. When the AFI is IPv4 Address-family and the SAFI is MDT, the value of the tuple will contain the IPv4 address of the PE sourcing the CE- learnt VPNv4 prefixes, and this attribute will accompany the VPNv4 prefix advertisement. The usage of this attribute for this AFI/SAFI is described in [MT-DISC]. 7. Capability Advertisement A BGP speaker that wishes to exchange the MDT SAFI, MUST use the MP_EXT Capability Code as defined in [BGP-MP], to advertise the corresponding (AFI, SAFI) pair. A BGP speaker MAY participate in the distribution of MDT information. draft-nalawade-mdt-safi-00.txt [Page 3] Internet Draft draft-nalawade-idr-mdt-safi-00.txt August 2004 8. Operation A BGP Speaker that receives the Capability for the MDT SAFI, MAY advertise the MDT SAFI prefixes to that peer. The prefixes in the MDT SAFI are populated by the PEs that advertise their CE-learnt prefixes. 9. Security Considerations This extension to BGP does not change the underlying security issues. 10. Acknowledgements The authors would like to thank IJsbrand Wijnands for his contr- ibution towards the Connector Attribute needed for the IPv4-MDT SAFI as described in [MT-DISC]. The authors would also like to thank Shyam Suri, Ruchi Kapoor, Shyam Suri, Yiqun Cai, Dan Tappan, Jennifer Li, Yi Chou, Arjen Boers for their comments and contrib- utions. We would also like to thank Bhavani Parise for his review and comments. 11. Normative References [BGP-4] Rekhter, Y. and T. Li (editors), "A Border Gateway Protocol 4 (BGP-4)", Internet Draft draft-ietf-idr-bgp4-17.txt, January 2002. [BGP-CAP] Chandra, R., Scudder, J., "Capabilities Advertisement with BGP-4", draft-ietf-idr-rfc2842bis-02.txt, April 2002. [BGP-SSA] Kapoor R., Nalawade G., ôBGPv4 SAFI-Specific Attributeö, draft-nalawade-kapoor-bgp-ssa-00.txt, June 2003. [MULTI-BGP] Bates et al, Multiprotocol Extensions for BGP-4, draft- ietf-idr-rfc2858bis-02.txt, work in progress. [MT-DISC] Wijnands, I., Nalawade, G., Multicast Tunnel discovery and RPF connector, wijnands-mt-discovery-00.txt, work in progress. 12. Author's Addresses Gargi Nalawade 170 Tasman Drive San Jose, CA, 95134 E-mail: gargi@cisco.com Arjun Sreekantiah 170 Tasman Drive San Jose, CA, 95134 E-mail: gargi@cisco.com draft-nalawade-mdt-safi-00.txt [Page 4] Internet Draft draft-nalawade-idr-mdt-safi-00.txt August 2004 13. Intellectual Property Statement Cisco Systems may seek patent or other intellectual property protection for some of all of the technologies disclosed in this document. If any standards arising from this document are or become protected by one or more patents assigned to Cisco Systems, Cisco intends to disclose those patents and license them on reasonable and non-discriminatory terms. 14. Full Copyright Statement Copyright (C) The Internet Society (2001). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS 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." 15. Expiration Date This memo is filed as , and expires August, 2004. draft-nalawade-mdt-safi-00.txt [Page 5]