Network Working Group Tissa Senevirathne Internet Draft (Force10) Document: draft-tsenevir-bgp-l2vpn-02.txt Loa Andersson Category: Informational (Utfors AB) May 2002 Auto-Discovery of VPLS Membership and Configuration Using BGP-MP Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026 [1]. 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. For potential updates to the above required-text see: http://www.ietf.org/ietf/1id-guidelines.txt 1. Abstract Membership and configuration discovery is a key component in Layer 2 VPN infrastructure. This document presents use of BGP-MP extensions for VPLS Membership and configuration discovery. More specifically, this document adapts generic VPN discovery methods presented in [2] for VPLS Membership and Configuration discovery. Senevirathne Informational û November 2002 1 draft-tsenevir-bgp-l2vpn-02.txt May 2002 2. Conventions used in this document 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 [3]. Placement of This Memo in Sub-IP Area RELATED DOCUMENTS: WHERE DOES IT FIT IN THE PICTURE OF THE SUB-IP WORK PPVPN WHY IS IT TARGETED AT THIS WG PPVPN WG charter specifies explicitly to consider BGP-VPN services, more specifically based on RFC 2547. In addition WG charter includes Virtual Private LAN Services (VPLS) and VPN auto-discovery. JUSTIFICATION Layer 2 VPN services are gaining popularity in emerging metro services infrastructure. Ability to automatically discover configuration and membership information enables metro service providers to manage large VPLS networks easily. Absence of such auto-discovery leads to manual configuration of VPLS services. Such manual configuration is not only tedious and less flexible, but also increases administrative costs. 3. Introduction Ability to automatically discover configuration and membership information enables metro service providers to manage large VPLS networks easily. Absence of such auto-discovery leads to manual configuration of Layer 2 VPN services. Such manual configuration is not only tedious and less flexible, but also increases administrative costs. The VPN service introduced in [4] is widely used to provide Layer 3 VPN services by service providers. As Layer 2 VPN becomes available, the same providers may be required to provide both Layer 2 and Layer 3 VPN services. Ability to use the same set of control protocols to provide two classes of VPN not only provide flexibility but also allow investment protection and migration from one class to another or co-offering. In this document we define specific details required to implement VPLS membership and configuration discovery using methods out lined Senevirathne Informational û November 2002 2 draft-tsenevir-bgp-l2vpn-02.txt May 2002 in [2]. The architecture and requirements for VPLS can be found in [5] and [6]. In this document we assume readers are familiar with terminology and concepts used in [2] [4] [5] [6]. 4. VPLS Membership and Configuration discovery When providing VPLS services, participating PE devices are required to obtain key parameters such as; end-points or membership information and VLAN(usage) information. End-points or Membership information PE devices that participate in a given VPLS are defined by common membership information. A given PE device MAY support more than one VPLS. VLAN span (usage) VLAN span provides a sub-scope within the VPLS. VLAN may span over a subset of end-points. 5. BGP-MP encoding for VPLS discovery . Encode VPLS-ID (L2-VPN-ID) using VPN-ID extended community [2]. . Use Extended Communities Attributes to specify the VLAN information applicable to given VPLS-ID. 5.1 Encoding of NLRI 5.1.1 Layer 2 VPN AFI [2] specifies a common AFI for auto-discovery of Layer 2 VPN. This AFI is common to all models of Layer 2 VPN. Actual value of the Layer 2 VPN AFI [TBD]. 5.1.2 VPLS SAFI SAFI 0x[TBD] is used to denote that NLRI is related to VPLS auto- discovery. 5.1.3 Encoding NLRI for VPLS NLRI carries IP address of the PE device that is advertising the discovery information. VPLS auto-discovery NLRI is a 8 byte Route Distinguisher (RD). IP address of the PE is encoded as part of the NLRI. Route Distinguisher Senevirathne Informational û November 2002 3 draft-tsenevir-bgp-l2vpn-02.txt May 2002 The Route Distinguisher for VPLS is coded as follows. Type field - 4 bytes Value field û 4 bytes Type field The value of the type field indicates that it carries the IP address of the PE device. Type field = 0x0001 indicates that the RD carries IPV4 address of the PE device. All other values in Type field are reserved. Value field IP address - 4 bytes. 5.2 Encoding VLAN extended communities attribute A new extended community is used to carry the VLAN information. This attribute is transitive across the autonomous system boundary. The value for TYPE field for extended community attribute will be assigned by IANA. Assigned number subfield contain the 12 bit VLAN id pre-pended with required zero (0). Filtering based on VLAN and VPN-ID extended community attributes allow a PE device to accept or reject VLAN based on local policies. 6.0 Further discussion When Layer 2 VPNs PE devices are connected to more than one service provider the AS number in the RD is used to uniquely identify the Layer 2 VPN membership. 7. Security Considerations Security issues relevant to Layer 2 VPN are discussed in [6] and Security issues relevant to use of 2547bis are discussed in [4]. 8. References 1 Bradner, S., "The Internet Standards Process -- Revision 3", BCP 9, RFC 2026, October 1996. 2 Ould-Brahim, H , et. al, Using BGP as an Auto-Discovery Mechanism for Network-based VPNS. Senevirathne Informational û November 2002 4 draft-tsenevir-bgp-l2vpn-02.txt May 2002 3 Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997 4 Rosen, E., et.al., BGP/MPLS VPNs, RFC 2547, March 1999. 5 Senevirathn, T., et.al, Requirements for Network Based Layer 2 VPN, Work in Progress, May 2001. 6 Senevirathne, T., et.al., A Framework for Virtual Metropolitan Internetworks (VMI), Work In Progress, February 2001. 9. Acknowledgments Increasing popularity of Layer 2 VPN services motivated us to publish this work. We wish to acknowledge valuable comments and suggestions provided by Eric Rosen and Yakov Rekhter. 10. Author's Addresses Tissa Senevirathne Force10 Networks 1440, McCarthy Blvd, Milpitas, CA Phone: 408-965-5103 Email: tsenevir@hotmail.com m Loa Andersson Utfors AB Senevirathne Informational û November 2002 5 draft-tsenevir-bgp-l2vpn-02.txt May 2002 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 implmentation 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 Senevirathne Informational û November 2002 6