Network Working Group M. Chen Internet-Draft Huawei Intended status: Standards Track G. Mirsky Expires: April 16, 2015 Ericsson October 13, 2014 Extensions to OSPF for Source Identifier Distribution draft-chen-ospf-source-identifier-distribution-00 Abstract A Source Identifier (SI) is carried in an MPLS Source Label and used to identify (one of) the ingress LSR(s) to a specific LSP. This document defines extensions to OSPF protocol for distribution of the correlation of a SI to an specific LSR. Therefore, the egress and intermediate LSRs can determine from which LSR an MPLS packet is sent. This document also defines OSPF extensions to advertise the Source Label Capability (SLC) of each LSR that indicates whether an LSR can properly process the Source Label Indicator (SLI) special purpose label and Source Label (SL). With the SLC, an ingress LSR can determine whether it is allowed to insert a SL into the label stack for a specific LSP. 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 RFC 2119 [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 http://datatracker.ietf.org/drafts/current/. 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." This Internet-Draft will expire on April 16, 2015. Chen & Mirsky Expires April 16, 2015 [Page 1] Internet-Draft OSPF Source Identifier Distribution October 2014 Copyright Notice Copyright (c) 2014 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must 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. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Extensions to OSPF . . . . . . . . . . . . . . . . . . . . . 3 3. Elements of Procedure . . . . . . . . . . . . . . . . . . . . 3 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . 4 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 4 7.1. Normative References . . . . . . . . . . . . . . . . . . 4 7.2. Informative References . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction As defined in [I-D.chen-mpls-source-label], a Source Identifier (SI) is a number in the range of [16, 65535]. Each node in a domain will be allocated one or more unique SIs. A SI is carried in an MultiProtocol Label Switching (MPLS) Source Label (SL) and used to identify (one of) the ingress Label Switching Router (LSR) to a specific Label Switched Path (LSP). To identify from where an MPLS packet is sent, the egress/ intermediate LSRs need to know to which ingress LSR a SI is correlated. Therefore, a mechanism to distribute the correlation of a SI to its correlated LSR is required. In addition, for an ingress LSR, before inserting a SL in the label stack of an LSP, it needs to know whether the egress LSR has the capability to process the SLI and SL, otherwise the packet will be dropped at the egress LSR. The capability is called Source Label Capability (SLC). Chen & Mirsky Expires April 16, 2015 [Page 2] Internet-Draft OSPF Source Identifier Distribution October 2014 This document defines extensions to OSPF protocol to distribute SI to LSR mapping and advertise the SLC of each LSR. 2. Extensions to OSPF The Source Identifier TLV is defined to distribute the SI(s) to ingress LSR mapping information and the SLC. No sub-TLV is currently defined for the Source Identifier TLV. The Source Identifier TLV is advertised in an OSPF Router Information (RI) [RFC4790] Link State Advertisement (LSA), it has the following format: 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Router ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved | Source Identifier 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ ... ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved | Source Identifier n | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1 - OSPF Source Identifier TLV format The value of "Type" field is TBD1. The "Length" field defines the length of the Reserved and Source Identifier fields in octets, which excludes the Router ID field. Each "Source Identifier" field (20 bits) contains a SI that identifies the advertising LSR. The "Reserved" field MUST be set to zero when sending and MUST be ignored when received. 3. Elements of Procedure The Source Identifier TLV is carried in the OSPF Router Information (RI) LSA that is defined in [RFC4790]. All the procedures that defined in [RFC4790] are inherited here. The flooding scope of the Source Identifier TLV can be either area local or entire OSPF domain. The flooding scope is controlled by the Chen & Mirsky Expires April 16, 2015 [Page 3] Internet-Draft OSPF Source Identifier Distribution October 2014 Opaque LSA type in OSPFv2 [RFC2370] and by the S1 and S2 bits in OSPFv3 [RFC2740]. If the flooding scope is area local, the Source Identifier TLV MUST be carried within an OSPFv2 Type 10 RI LSA or within an OSPFv3 RI LSA with the S1 bit set and the S2 bit clear. If the flooding scope is the entire IGP domain, the Source Identifier TLV MUST be carried within an OSPFv2 Type 11 RI LSA or within an OSPFv3 RI LSA with the S1 bit clear and the S2 bit set. The Source Identifier TLV is an optional TLV. Upon receipt the TLV, a router will silently ignore the TLV as defined in [RFC4790] if it does not support it. If Source Identifier TLV is not present that MUST be interpreted as signaling of non-support of SLC by the LSR. Presence of a Source Identifier TLV MUST be interpreted as support of SLC by the LSR. A Source Identifier TLV MUST appear only one time in an LSA. When received, only first Source Identifier TLV is valid, subsequent Source Identifier TLVs MUST be ignored. 4. IANA Considerations IANA is requested to assign a new TLV code point for the Source Identifier TLV carried within the Router Information LSA. Type Value TLV Name Reference ---------- ------------------ -------------- TBD1 Source Identifier (this document) 5. Security Considerations TBD. 6. Acknowledgements 7. References 7.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2370] Coltun, R., "The OSPF Opaque LSA Option", RFC 2370, July 1998. [RFC2740] Coltun, R., Ferguson, D., and J. Moy, "OSPF for IPv6", RFC 2740, December 1999. [RFC4790] Newman, C., Duerst, M., and A. Gulbrandsen, "Internet Application Protocol Collation Registry", RFC 4790, March 2007. Chen & Mirsky Expires April 16, 2015 [Page 4] Internet-Draft OSPF Source Identifier Distribution October 2014 7.2. Informative References [I-D.chen-mpls-source-label] Chen, M., Xu, X., Li, Z., Fang, L., and G. Mirsky, "MultiProtocol Label Switching (MPLS) Source Label", draft-chen-mpls-source-label-05 (work in progress), July 2014. Authors' Addresses Mach(Guoyi) Chen Huawei Email: mach.chen@huawei.com Greg Mirsky Ericsson Email: Gregory.mirsky@ericsson.com Chen & Mirsky Expires April 16, 2015 [Page 5]