BIER Shaofu. Peng Internet-Draft Zheng. Zhang Intended status: Standards Track ZTE Corporation Expires: December 30, 2018 June 28, 2018 Global vpnid advertisement in BIER overlay draft-pengzhang-bier-global-vpnid-00 Abstract This document specifies a method to achieve multipoint VPN interconnection through a BIER domain. Requirements Language 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 RFC2119. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. 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Code Components extracted from this document must Peng & Zhang Expires December 30, 2018 [Page 1] Internet-Draft BIER GLOBAL VPNID June 2018 include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Problem statement . . . . . . . . . . . . . . . . . . . . . . 2 3. Solution . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3.1. Advertisement . . . . . . . . . . . . . . . . . . . . . . 3 3.2. Encapsulation . . . . . . . . . . . . . . . . . . . . . . 4 3.3. Decapsulation . . . . . . . . . . . . . . . . . . . . . . 4 3.4. Formats . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 5. Security Considerations . . . . . . . . . . . . . . . . . . . 5 6. Normative References . . . . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 1. Terminology This document uses terminologies defined in [RFC8279], [RFC6513], [RFC6514], [I-D.ietf-bier-mld]. 2. Problem statement BIER (Bit Indexed Explicit Replication) [RFC8279] introduces an architecture for the forwarding of multicast data packet. It provides optimal forwarding of multicast packet through a 'multicast domain'. It does not require explicitly building multicast distribution trees, nor does require intermediate nodes to maintain any per-flow state. BIER MVPN [I-D.ietf-bier-mvpn] introduces a method which using BIER as multicast tunnels (P-tunnels) to carry multicast traffic across the BIER domain. The advertising method from [RFC6513] and [RFC6514] is general and flexible, but it is complicated in some situations at the same time because of the program of many parameters, like RD, RT, etc. In many situations which only interconnect different sites across a domain, the comprehensive MVPN configuration increases the network administrative complication. In the other hand, BIER MVPN using upstream assigned label to indicate the corresponding multicast flow in a MVPN. The pair of ingress PE and upsteam assigned labels increases label administration and flow forwarding complication. [I-D.zzhang-bess-mvpn-evpn-aggregation-label] arises a discussion about using common label assigned by controller in MVPN. But in a Peng & Zhang Expires December 30, 2018 [Page 2] Internet-Draft BIER GLOBAL VPNID June 2018 network without a controller, it is still a problem to achieve the multipoint interconnection without MVPN configuration. So for the networks that need flow isolation across domain but do not need complicated configuration, this document specifies a method to achieve multipoint VPN interconnection across a BIER domain by advertising global vpn-id in BIER forwarding overlay, and defines encapsulation and forwarding functions to carry and execute the global vpn-id. It is similar as the usage of VNI-VSID in case of EVPN VXLAN/ NVGRE described in [I-D.ietf-bier-evpn]. 3. Solution The multipoint VPN here means some flows should be forwarded to multiple edge routers across a domain. In the simple multipoint interconnection situations that does not deploy MVPN configuration like RD, RT, etc., a global vpn-id is used to indicate the corresponding VPN. This global vpn-id is encapsulated between BIER header and actual data packet. The BIER forwarding function is also modified to execute this kind of packet. 3.1. Advertisement BIER overlay protocols include BMLD [I-D.ietf-bier-mld], MVPN [I-D.ietf-bier-mvpn], and PIM [I-D.ietf-bier-pim-signaling], EVPN [I-D.ietf-bier-evpn]. Global vpn-id extension should be added in these BIER overlay protocols by a TLV format. When using BGP as BIER overlay protocol to advertise global vpn-id, specific VPN parameters like RD, RT defined in [RFC6513] and [RFC6514] need not be used. A BIER domain edge router can belong to several VPNs. A unique global vpn-id is assigned to a particular VPN. An edge router belongs to several VPNs is assigned several global vpn-ids. Edge routers belong to a same VPN should be assigned a same global vpn-id. The two edge routers which have same global vpn-id indicates that the two routers belong to a same particular VPN. When BIER domain edge routers exchange BIER overlay information, the edge routers belong to one or more VPNs should advertise the corresponding global vpn-ids extension. After a router receives global vpn-id extensions from the other edge routers, the router MUST store the edge routers which have same global vpn-ids with local VPNs. Peng & Zhang Expires December 30, 2018 [Page 3] Internet-Draft BIER GLOBAL VPNID June 2018 The router SHOULD store the edge routers which have different global vpn-ids with local VPNs in order to increase converged efficiency that caused by configuration modification. 3.2. Encapsulation After ingress router gathers the information of edge routers which have same global vpn-ids, ingress router generates forwarding items which include global vpn-id and BFR-ids of egress routers. When ingress router encapsulates the data packet which should be sent to the egress routers according to a global vpn-id, the value of global vpn-id MUST be added between BIER header and actual data packet. The encapsulation function is the same as [RFC8296], the 'Proto' field in BIER header should be set to the value for a new type of global vpn-id. The forwarding of intermediate routers is unchanged according to the forwarding function defined in [RFC8279]. 3.3. Decapsulation Finally the packet reaches egress routers. Egress router looks for the forwarding items indexed by the global vpn-id according to the 'Proto' field in BIER header. After decapsulation, egress router forwards data packet to corresponding local receivers. 3.4. Formats [RFC2685] defines a globally unique VPN identifier to connect same VPN in different sites. The format of global vpn-id defined in [RFC2685] is 7 octets. But in actually deployment, a global vpn-id with 20 bits is enough to indicate the corresponding VPN. So the global vpn-id can be used as BIFT-ID defined in [RFC8296]directly. When MLD protocol is used as BIER overlay, a new type of TLV is added in BMLD report messages. When BGP protocol is used as BIER overlay, a new type of TLV is added in BGP update message. When PIM protocol is used as BIER overlay, a new type of TLV is added in PIM join/ prune messages. For the edge routers which act as ingress routers or egress routers, the corresponding global vpn-ids are carried in the new TLV. And the BFR-id of the router itself is also included in the TLV. Peng & Zhang Expires December 30, 2018 [Page 4] Internet-Draft BIER GLOBAL VPNID June 2018 4. IANA Considerations A new type which indicates the global vpn-id should be added in BIER 'Proto' assignment. A new type of global vpn-id extension should be added in each BIER overlay protocols, includes MLD, PIM, BGP. 5. Security Considerations There is no further security requirements in this document. 6. Normative References [I-D.ietf-bier-evpn] Zhang, Z., Przygienda, T., Sajassi, A., and J. Rabadan, "EVPN BUM Using BIER", draft-ietf-bier-evpn-01 (work in progress), April 2018. [I-D.ietf-bier-mld] Pfister, P., Wijnands, I., Venaas, S., Wang, C., Zhang, Z., and M. Stenberg, "BIER Ingress Multicast Flow Overlay using Multicast Listener Discovery Protocols", draft-ietf- bier-mld-00 (work in progress), June 2017. [I-D.ietf-bier-mvpn] Rosen, E., Sivakumar, M., Aldrin, S., Dolganow, A., and T. Przygienda, "Multicast VPN Using BIER", draft-ietf-bier- mvpn-11 (work in progress), March 2018. [I-D.ietf-bier-pim-signaling] Bidgoli, H., Dolganow, A., Kotalwar, J., Xu, F., mishra, m., and Z. Zhang, "PIM Signaling Through BIER Core", draft-ietf-bier-pim-signaling-03 (work in progress), June 2018. [I-D.zzhang-bess-mvpn-evpn-aggregation-label] Zhang, Z., Rosen, E., Lin, W., Li, Z., and I. Wijnands, "MVPN/EVPN Tunnel Aggregation with Common Labels", draft- zzhang-bess-mvpn-evpn-aggregation-label-01 (work in progress), April 2018. [RFC2685] Fox, B. and B. Gleeson, "Virtual Private Networks Identifier", RFC 2685, DOI 10.17487/RFC2685, September 1999, . [RFC6513] Rosen, E., Ed. and R. Aggarwal, Ed., "Multicast in MPLS/ BGP IP VPNs", RFC 6513, DOI 10.17487/RFC6513, February 2012, . Peng & Zhang Expires December 30, 2018 [Page 5] Internet-Draft BIER GLOBAL VPNID June 2018 [RFC6514] Aggarwal, R., Rosen, E., Morin, T., and Y. Rekhter, "BGP Encodings and Procedures for Multicast in MPLS/BGP IP VPNs", RFC 6514, DOI 10.17487/RFC6514, February 2012, . [RFC8279] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A., Przygienda, T., and S. Aldrin, "Multicast Using Bit Index Explicit Replication (BIER)", RFC 8279, DOI 10.17487/RFC8279, November 2017, . [RFC8296] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A., Tantsura, J., Aldrin, S., and I. Meilik, "Encapsulation for Bit Index Explicit Replication (BIER) in MPLS and Non- MPLS Networks", RFC 8296, DOI 10.17487/RFC8296, January 2018, . Authors' Addresses Shaofu Peng ZTE Corporation EMail: peng.shaofu@zte.com.cn Zheng(Sandy) Zhang ZTE Corporation EMail: zzhang_ietf@hotmail.com Peng & Zhang Expires December 30, 2018 [Page 6]