IDR Working Group Weiguo Hao Donald Eastlake Internet Draft Huawei Intended status: Standard Track Susan Hares Hickory Hill Consulting Expires: November 2015 July 28, 2015 Distribution of TRILL Link-State using BGP draft-hao-idr-ls-trill-02.txt Abstract This draft describes a TRILL link state and MAC address reachability information distribution mechanism using a BGP LS extension. External components such as an SDN Controller can use the information for topology visibility, troubleshooting, network automation, etc. Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and 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. Copyright Notice Copyright (c) 2015 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 Hao & et,al Expires January 28, 2016 [Page 1]
Internet-Draft BGP LS For TRILL July 2015 publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Table of Contents 1. Introduction ................................................ 2 2. Conventions used in this document............................ 3 3. Carrying TRILL Link-State Information in BGP................. 4 3.1. Node Descriptors........................................ 5 3.1.1. IGP Router-ID...................................... 6 3.2. MAC Address Descriptors................................. 6 3.2.1. MAC-Reachability TLV............................... 7 3.3. The BGP-LS Attribute.................................... 7 3.3.1. Node Attribute TLVs................................ 7 3.3.1.1. Node Flag Bits TLV............................ 7 3.3.1.2. Opaque Node Attribute TLV..................... 8 3.3.2. Link Attribute TLVs................................ 9 4. Operational Considerations................................... 9 5. Security Considerations..................................... 10 6. IANA Considerations ........................................ 11 7. References ................................................. 11 7.1. Normative References................................... 11 7.2. Informative References................................. 12 8. Acknowledgments ............................................ 12 1. Introduction BGP has been extended to distribute IGP link-state and traffic engineering information to some external components [I-D.ietf-idr- ls-distribution], such as the PCE and ALTO servers. The information can be used by these external components to compute a MPLS-TE path across IGP areas, visualize and abstract network topology, and the like. TRILL (Transparent Interconnection of Lots of Links) protocol [RFC6325] provides a solution for least cost transparent routing in multi-hop networks with arbitrary topologies and link technologies, using [IS-IS] [RFC7176] link-state routing and a hop count. TRILL switches are sometimes called RBridges (Routing Bridges). The TRILL protocol has been deployed in many data center networks. Data center automation is a vital step to increase the speed and agility of business. An SDN controller as an external component normally can be used to provide centralized control and automation for the data center network. Making a holistic view of whole network Hao & et,al Expires January 28, 2016 [Page 2]
Internet-Draft BGP LS For TRILL July 2015 topology available to the SDN controller is an important part for data center network automation and troubleshooting. +-------------+ | SDN | --------| Controller |-------- | +-------------+ | | | + + + + + +-----------+ + | | +--------+ |IP Network | +--------+ | | +----+ +----+ | | +---+ +---+ | | | | | | | | +---+ +---+ |ES1|-|RB1|-| Area 1 |-|BRB1| |BRB2|-| Area 2 |-|RB2|-|ES2| +---+ +---+ | | +----+ +----+ | | +---+ +---+ | | | | | | +--------+ +-----------+ +--------+ |<----TRILL ------>|<IP tunnel>|<-----TRILL ----->| Figure 1: TRILL interconnection In Data Center interconnection scenario illustrated in figure 1, a single SDN Controller or network management system (NMS) can be used for end-to-end network management. End-to-end topology visibility on the SDN controller or NMS is very useful for whole network automation and troubleshooting. BGP LS can be used by the external SDN controller to collect multiple TRILL domain's link-state. If ESADI (End Station Address Distribution Information) protocol [RFC7357] is used for control plane MAC learning in each data center, BGP LS also can be used for MAC address reachability information synchronization across multiple TRILL domains. End-to-end unicast forwarding paths can be calculated based on the synchronized information. This document describes the detailed BGP LS extension mechanisms for TRILL link state and MAC address reachability information distribution. 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 [RFC2119]. Hao & et,al Expires January 28, 2016 [Page 3]
Internet-Draft BGP LS For TRILL July 2015 BGP - Border Gateway Protocol BGP-LS - BGP Link-State Data label - VLAN or FGL (Fine Grained Label [RFC7172]) IS - Intermediate System (for this document, all relevant intermediate systems are RBridges) NLRI - Network Layer Reachability Information SDN - Software Defined Networking RBridge - A device implementing the TRILL protocol TRILL - Transparent Interconnection of Lots of Links 3. Carrying TRILL Link-State Information in BGP In [I-D.ietf-idr-ls-distribution], four NLRI types are defined as follows: Node NLRI, Link NLRI, IPv4 Topology Prefix NLRI and IPv6 Topology Prefix NLRI. For TRILL link-state distribution, the Node NLRI and Link NLRI are extended to carry layer 3 gateway role and link MTU information. TRILL specific attributes are carried using opaque Node Attribute TLVs, such as nickname, distribution tree number and identifiers, interested VLANs/Fine Grained Label, and multicast group address, and etc. To differentiate TRILL protocol from layer 3 IGP protocol, a new TRILL Protocol-ID is defined. +-------------+----------------------------------+ | Protocol-ID | NLRI information source protocol | +-------------+----------------------------------+ | 1 | IS-IS Level 1 | | 2 | IS-IS Level 2 | | 3 | OSPFv2 | | 4 | Direct | | 5 | Static configuration | | 6 | OSPFv3 | | TBD | TRILL | +-------------+----------------------------------+ Table 1: Protocol Identifiers ESADI (End Station Address Distribution Information) protocol [RFC7357] is a per data label control plane MAC learning solution. MAC address reachability information is carried in ESADI packets. Hao & et,al Expires January 28, 2016 [Page 4]
Internet-Draft BGP LS For TRILL July 2015 Compared with data plane MAC learning solution, ESADI protocol has security and fast update advantage that are pointed out in [RFC7357]. For an RBridge that is announcing participation in ESADI, the RBridge can distribute MAC address reachability information to external components using BGP. A new NLRI type of ''MAC Reachability NLRI'' is requested for the MAC address reachability distribution. +------+---------------------------+ | Type | NLRI Type | +------+---------------------------+ | 1 | Node NLRI | | 2 | Link NLRI | | 3 | IPv4 Topology Prefix NLRI | | 4 | IPv6 Topology Prefix NLRI | | TBD | MAC Reachability NLRI | +------+---------------------------+ Table 2: NLRI Types The MAC Reachability NLRI uses the format as shown in the following figure. 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 +-+-+-+-+-+-+-+-+ | Protocol-ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Identifier | | (64 bits) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ // Local Node Descriptor (variable) // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ // MAC Address Descriptors (variable) // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2: The MAC Reachability NLRI format 3.1. Node Descriptors The Node Descriptor Sub-TLV types include Autonomous System and BGP- LS Identifier, iS-IS Area-ID and IGP Router-ID. TRILL uses a fixed zero Area Address as specified in [RFC6325], Section 4.2.3. This is encoded in a 4-byte Area Address TLV (TLV #1) as follows: Hao & et,al Expires January 28, 2016 [Page 5]
Internet-Draft BGP LS For TRILL July 2015 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 0x01, Area Address Type | (1 byte) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 0x02, Length of Value | (1 byte) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 0x01, Length of Address | (1 byte) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 0x00, zero Area Address | (1 byte) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3: Area Address TLV 3.1.1. IGP Router-ID Similar to layer 3 IS-IS, TRILL protocol uses 7-octet "IS-IS ID" as the identity of an RBridge or a pseudonode, IGP Router ID sub-TLV in Node Descriptor TLVs contains the 7-octet "IS-IS ID". In TRILL network, each RBridge has a unique 48-bit (6-octet) IS-IS System ID. This ID may be derived from any of the RBridge's unique MAC addresses or configured. A pseudonode is assigned a 7-octet ID by the DRB (Designated RBridge) that created it, the DRB is similar to the "Designated Intermediate System" (DIS) corresponding to a LAN. 3.2. MAC Address Descriptors The ''MAC Address Descriptor'' field is a set of Type/Length/Value (TLV) triplets. ''MAC Address Descriptor'' TLVs uniquely identify an MAC address reachable by a Node. The following attributes TLVs are defined: +--------------+-----------------------+----------+-----------------+ | TLV Code | Description | Length | Value defined | | Point | | | in: | +--------------+-----------------------+----------+-----------------+ | 1 | MAC-Reachability | variable | section 3.2.1 | +--------------+-----------------------+----------+-----------------+ Table 3: MAC Address Descriptor TLVs Hao & et,al Expires January 28, 2016 [Page 6]
Internet-Draft BGP LS For TRILL July 2015 3.2.1. MAC-Reachability TLV +-+-+-+-+-+-+-+-+ | Type= MAC-RI | (1 byte) +-+-+-+-+-+-+-+-+ | Length | (1 byte) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...+-+-+-+-+-+-+-+ |V|F| RESV | Data Label | (4 bytes) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MAC (1) (6 bytes) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ................. | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MAC (N) (6 bytes) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 4: MAC-Reachability TLV format Length is 4 plus a multiple of 6. The bits of 'V' and 'F' are used to identify Data Label type and are defined as follows: +----------+-------------------------+ | Bit | Description | +----------+-------------------------+ | 'V' | VLAN | | 'F' | Fine Grained Label | +----------+-------------------------+ Table 4: Data Label Type Bits Definitions Notes: If BGP LS is used for NVO3 network MAC address distribution between external SDN Controller and NVE, Data Label can be used to represent 24 bits VN ID. 3.3. The BGP-LS Attribute 3.3.1. Node Attribute TLVs 3.3.1.1. Node Flag Bits TLV A new Node Flag bit is added as follows: Hao & et,al Expires January 28, 2016 [Page 7]
Internet-Draft BGP LS For TRILL July 2015 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |O|T|E|B|G| Reserved | +-+-+-+-+-+-+-+-+-+-+-+ Figure 5: Node Flag Bits TLV format The new bit and remaining reserved bits are defined as follows: +----------+----------------------------+-----------+ | Bit | Description | Reference | +----------+----------------------------+-----------+ | 'G' | Layer 3 Gateway Bit | [RFC7176] | | Reserved | Reserved for future use | | +----------+----------------------------+-----------+ Table 5: Node Flag Bits Definitions 3.3.1.2. Opaque Node Attribute TLV The Opaque Node Attribute TLV is used as the envelope to transparently carry TRILL specific information. In [RFC7176], there are the following Sub-TLVs in the Router Capability and MT- Capability TLVs and the Group Address (GADDR) TLV that need to be carried. Future possible TRILL TLVs/Sub-TLVs extension also can be carried using the Opaque Node Attribute TLV. Hao & et,al Expires January 28, 2016 [Page 8]
Internet-Draft BGP LS For TRILL July 2015 Descriptions IS-IS TLV/Sub-TLV ------------------------------------ TRILL-VER 22/13 NICKNAME 22/6 TREES 22/7 TREE-RT-IDs 22/8 TREE-USE-IDs 22/9 INT-VLAN 22/10 VLAN-GROUP 22/14 INT-LABEL 22/15 RBCHANNELS 22/16 AFFINITY 22/17 LABEL-GROUP 22/18 GMAC-ADDR 142/1 GIP-ADDR 142/2 GIPV6-ADDR 142/3 GLMAC-ADDR 142/4 GLIP-ADDR 142/5 GLIPV6-ADDR 142/6 Table 6: TRILL TLVs/Sub-TLVs 3.3.2. Link Attribute TLVs Link attribute TLVs are TLVs that may be encoded in the BGP-LS attribute with a link NLRI. Besides the TLVs that has been defined in [I-D.ietf-idr-ls-distribution] section 3.3.2 table 9, the following 'Link Attribute' TLV is provided for TRILL. +-----------+----------------+--------------+------------------+ | TLV Code | Description | IS-IS TLV | Defined in: | | Point | | /Sub-TLV | | +-----------+----------------+--------------+------------------+ | TBD | Link MTU | 22/28 | [RFC7176]/2.4 | +-----------+----------------+--------------+------------------+ Table 7: Link Attribute TLVs 4. Operational Considerations This document does not require any MIB or Yang model to configure operational parameters. An implementation of this specification[idr-ls-trill], MUST do the malformed attribute checks below, and if it detects a malformed Hao & et,al Expires January 28, 2016 [Page 9]
Internet-Draft BGP LS For TRILL July 2015 attribute, it should use the 'Attribute Discard' action per [I- D.ietf.idr-error-handling] section 2. An implementation MUST perform the following expanded [BGP-LS] syntactic check for determining if the message is malformed: o Does the sum of all TLVs found in the BGP LS attribute correspond to the BGP LS path attribute length ? o Does the sum of all TLVs found in the BGP MP_REACH_NLRI attribute correspond to the BGP MP_REACH_NLRI length ? o Does the sum of all TLVs found in the BGP MP_UNREACH_NLRI attribute correspond to the BGP MP_UNREACH_NLRI length ? o Does the sum of all TLVs found in a Node-, Link, prefix (IPv4 or IPv6) NLRI attribute correspond to the Node-, Link- or Prefix Descriptors 'Total NLRI Length' field ? o Does any fixed length TLV correspond to the TLV Length field in this document ? o Does the sum of MAC reachability TLVs equal the length of the field? In addition, the following checks need to be made for the fields specific to the BGP LS for TRILL: o PROTOCOL ID is TRILL o NLRI types are valid per table 2 o MAC Reachability NLRI has correct format including: o Identifier (64 bits), o local node descriptor with AREA address TLV has the form found in figure 2, o opaque TLV support the range of ISIS-TLV/SUB-TLV shown in table 3, and link TLVs support the range in figure 8. 5. Security Considerations Procedures and protocol extensions defined in this document do not affect the BGP security model. See [RFC6952] for details. Hao & et,al Expires January 28, 2016 [Page 10]
Internet-Draft BGP LS For TRILL July 2015 6. IANA Considerations For all of the following assignments, [this document] is the reference. IANA is requested to assign one Protocol-ID for "TRILL" from the BGP-LS registry of Protocol-IDs. IANA is requested to assign one NLRI Type for "MAC Reachability" from the BGP-LS registry of NLRI Types. IANA is requested to assign one Node Flag bit for "Layer 3 Gateway" from the BGP-LS registry of BGP-LS Attribute TLVs. IANA is requested to assign one new TLV type for "Link MTU" from the BGP-LS registry of BGP-LS Attribute TLVs. 7. References 7.1. Normative References [1] [I-D.ietf-idr-ls-distribution] Gredler, H., Medved, J., Previdi, S., Farrel, A., and S.Ray, "North-Bound Distribution of Link-State and TE Information using BGP", draft-ietf-idr-ls- distribution-10(work in progress), January 2015. [2] [I-D.ietf.idr-error-handling] Enke, C., John, S., Pradosh, M., Keyur,P., "Revised Error Handling for BGP UPDATE Messages", draft-ietf-idr-error-handling-19(work in progress), April 2015. [3] [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [4] [RFC6325] Perlman, R., Eastlake 3rd, D., Dutt, D., Gai, S.,and A. Ghanwani, "Routing Bridges (RBridges): Base Protocol Specification", RFC 6325, July 2011. [5] [RFC7172] Eastlake 3rd, D., Zhang, M., Agarwal, P., Perlman, R., and D. Dutt, "Transparent Interconnection of Lots of Links (TRILL): Fine-Grained Labeling", RFC 7172, DOI 10.17487/RFC7172, May 2014, <http://www.rfc-editor.org/info/rfc7172>. [6] [RFC7176] Eastlake, D., Senevirathne, T., Ghanwani, A., Dutt, D., Banerjee, A.," Transparent Interconnection of Lots of Links (TRILL) Use of IS-IS'', May 2014. Hao & et,al Expires January 28, 2016 [Page 11]
Internet-Draft BGP LS For TRILL July 2015 [7] [RFC7357] - Zhai, H., Hu, F., Perlman, R., Eastlake 3rd, D., and O. Stokes, "Transparent Interconnection of Lots of Links (TRILL): End Station Address Distribution Information (ESADI) Protocol", RFC 7357, September 2014, <http://www.rfc- editor.org/info/rfc7357>. 7.2. Informative References 8. Acknowledgments Authors like to thank Jie Dong, Mingui Zhang, Qin Wu, Shunwan Wang, Zitao Wang, Lili Wang for their valuable inputs. Authors' Addresses Weiguo Hao Huawei Technologies 101 Software Avenue, Nanjing 210012 China Phone: +86-25-56623144 Email: haoweiguo@huawei.com Donald E. Eastlake Huawei Technologies 155 Beaver Street Milford, MA 01757 USA Phone: +1-508-333-2270 Email: d3e3e3@gmail.com Susan K. Hares Hickory Hill Consulting 7453 Hickory Hill Saline, MI 48176 USA Email: shares@ndzh.com Hao & et,al Expires January 28, 2016 [Page 12]