Network Working Group J. Dong Internet-Draft S. Zhuang Intended status: Standards Track Huawei Technologies Expires: January 9, 2020 G. Van de Velde Nokia July 8, 2019 BGP Extended Community for Identifying the Target Node draft-dong-idr-node-target-ext-comm-01 Abstract BGP has been used to distribute different types of routing and policy information in the network. In some cases, the information distributed may be only intended for one or several particular receiving BGP nodes in the network. However, BGP does not have a general mechanism for designating the receiving node of the routing information. This document defines a new type of BGP extended community called "Node Target". The mechanism of using the Node Target extended community to steer BGP route distribution to particular BGP nodes is specified. 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 https://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 January 9, 2020. Dong, et al. Expires January 9, 2020 [Page 1] Internet-Draft BGP Node Target Extended Community July 2019 Copyright Notice Copyright (c) 2019 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 (https://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. Node Target Extended Communities . . . . . . . . . . . . . . 3 2.1. IPv4 Node Target Extended Community . . . . . . . . . . . 3 2.2. IPv6 Node Target Extended Community . . . . . . . . . . . 4 3. Procedures . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 5. Security Considerations . . . . . . . . . . . . . . . . . . . 6 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 6 7.1. Normative References . . . . . . . . . . . . . . . . . . 6 7.2. Informative References . . . . . . . . . . . . . . . . . 6 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7 1. Introduction BGP [RFC4271] has been used to distribute different types of routing and policy information in the network. In some cases, the information distributed may be only intended for one or several particular receiving BGP nodes in the network. A typical use case is the distribution of BGP FlowSpec [RFC5575] [I-D.ietf-idr-rfc5575bis] policies to some particular BGP nodes. However, BGP does not have a general mechanism for designating the receiving nodes of the information to be distributed. Route Target (RT) as defined in [RFC4364] is used for the distribution of VPN routes into the target VPN Routing and Forwarding tables (VRFs) on a set of PE nodes. Although it is possible to use RTs to control the distribution of non VPN-specific information to a particular node, such mechanism is not applicable when the information to be distributed is VPN-specific and relies on RTs to match the target Dong, et al. Expires January 9, 2020 [Page 2] Internet-Draft BGP Node Target Extended Community July 2019 VRF. Thus a mechanism which is independent from the control of VPN route to VRF distribution is needed. Another possible way is to configure, on each router, a community and the corresponding policies to match the community to determine whether to accept the received routes. Such mechanism relies on manual configuration thus is considered error-prone. It is preferable by operators that an automatic approach can be provided. This document defines a new type of BGP extended community called "Node Target". The mechanism of using the Node Target extended community to steer BGP route distribution to particular BGP nodes is also specified. 2. Node Target Extended Communities 2.1. IPv4 Node Target Extended Community For IPv4 networks, this section defines a new BGP extended community [RFC4360] called "IPv4 Node Target Extended Community". It is a transitive extended community with type 0x01 and sub-type TBA. The format of IPv4 Node Target Extended Community is shown in Figure 1. 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 (0x01) | Sub-Type (TBA)| Target IPv4 Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Target IPv4 Address (cont.) | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1. IPv4 Node Target extended community Target IPv4 address field: A local IPv4 address of the target node. When the target IPv4 address is set to 0.0.0.0, it means all the BGP nodes in the network are the target nodes. Reserved field: Reserved for future use, MUST be set to zero on transmission and ignored on receipt. One or more IPv4 Node Target extended communities may be carried in a BGP Update message. Dong, et al. Expires January 9, 2020 [Page 3] Internet-Draft BGP Node Target Extended Community July 2019 2.2. IPv6 Node Target Extended Community For IPv6 networks, a new IPv6 Address Specific BGP Extended Community [RFC5701] called "IPv6 Node Target extended community" is defined. It is a transitive IPv6 address specific extended community with type 0x00 and sub-type TBA. The format of this extended community is shown in Figure 2. 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 (0x00) | Sub-Type (TBA)| Target IPv6 Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Target IPv6 Address (cont.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Target IPv6 Address (cont.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Target IPv6 Address (cont.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Target IPv6 Address (cont.) | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2. IPv6 Node Target extended community Target IPv6 address field: A IPv6 address of the target node. When the target IPv6 address is set to "0:0:0:0:0:0:0:0" ( :: ), it means all the BGP nodes in the network are the target nodes. Reserved field: Reserved for future use, MUST be set to zero on transmission and ignored on receipt. One or more IPv6 Node Target extended communities may be carried in a BGP Update message. 3. Procedures In this version only the usage of the proposed mechanism in the intra-AS scenario is described, more details about the inter-AS scenario is for further study. When a controller or BGP speaker plans to advertise some BGP information only to some particular BGP nodes in the network, it MUST put the IPv4 or IPv6 address of each target node into the IPv4 or IPv6 Node Target extended communities, and attach the IPv4 or IPv6 Node Target extended communities to the BGP Update message to be advertised. Dong, et al. Expires January 9, 2020 [Page 4] Internet-Draft BGP Node Target Extended Community July 2019 If a non-RR BGP speaker receives an Update message which contains one or more IPv4 or IPv6 Node Target extended communities, it MUST check the target IPv4 or IPv6 addresses carried in the extended communities. o If the target IPv4 or IPv6 address in any of the IPv4 or IPv6 Node Target extended community matches with one of the local IP addresses, the receiving BGP speaker is one of the target nodes of the information in the Update, and the information in the Update is eligible to be kept and installed by the receiving BGP speaker. o If the target IPv4 or IPv6 address in any of the IPv4 or IPv6 Node Target extended community does not match with any local IP address, the receiving BGP speaker is not the target node of information in the Update, the information in the received Update message MUST not be used. If a route-reflector (RR) receives an BGP Update message which contains one or more IPv4 or IPv6 Node Target extended communities, it MUST check the target IPv4 or IPv6 addresses carried in the IPv4 or IPv6 Node Target extended communities. o If the target IPv4 or IPv6 address in any of the IPv4 or IPv6 Node Target extended community matches with one of the local IP addresses, this RR is one of the target nodes of information in the Update, and such information is eligible to be kept and installed by this RR. If there is no other IPv4 or IPv6 Node Target extended communities in the Update, the RR MUST NOT advertise the information in this Update further to its neighbors. If there is other IPv4 or IPv6 Node Target extended communities, the RR SHOULD first remove the local matched Node Target extended community, then reflect the routes with the remaining Node Target Extended Communities according to [RFC4456]. o If the target IPv4 or IPv6 address in any of the IPv4 or IPv6 Node target extended community does not match with any local IP address, this RR is not the target node of routes in the Update, the rules defined in [RFC4456] are used for the reflection of the received route. 4. IANA Considerations This document requests that IANA assigns one new sub-type for "IPv4 Node Target extended community" from the "Transitive IPv4-Address- Specific Extended Community" registry of the "BGP extended communities" registry. Dong, et al. Expires January 9, 2020 [Page 5] Internet-Draft BGP Node Target Extended Community July 2019 This document requests that IANA assigns one new type for "IPv6 Node Target extended community" from the "Transitive IPv6-Address-Specific Extended Community" registry of the "BGP extended communities" registry. 5. Security Considerations This document does not change the security properties of BGP. 6. Acknowledgements The authors would like to thank Zhenbin Li and Ercin Torun for the discussion and review of this document. 7. References 7.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A Border Gateway Protocol 4 (BGP-4)", RFC 4271, DOI 10.17487/RFC4271, January 2006, . [RFC4360] Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended Communities Attribute", RFC 4360, DOI 10.17487/RFC4360, February 2006, . [RFC4456] Bates, T., Chen, E., and R. Chandra, "BGP Route Reflection: An Alternative to Full Mesh Internal BGP (IBGP)", RFC 4456, DOI 10.17487/RFC4456, April 2006, . [RFC5701] Rekhter, Y., "IPv6 Address Specific BGP Extended Community Attribute", RFC 5701, DOI 10.17487/RFC5701, November 2009, . 7.2. Informative References [I-D.ietf-idr-rfc5575bis] Loibl, C., Hares, S., Raszuk, R., McPherson, D., and M. Bacher, "Dissemination of Flow Specification Rules", draft-ietf-idr-rfc5575bis-17 (work in progress), June 2019. Dong, et al. Expires January 9, 2020 [Page 6] Internet-Draft BGP Node Target Extended Community July 2019 [RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February 2006, . [RFC5575] Marques, P., Sheth, N., Raszuk, R., Greene, B., Mauch, J., and D. McPherson, "Dissemination of Flow Specification Rules", RFC 5575, DOI 10.17487/RFC5575, August 2009, . Authors' Addresses Jie Dong Huawei Technologies Huawei Campus, No. 156 Beiqing Rd. Beijing 100095 China Email: jie.dong@huawei.com Shunwan Zhuang Huawei Technologies Huawei Campus, No. 156 Beiqing Rd. Beijing 100095 China Email: zhuangshunwan@huawei.com Gunter Van de Velde Nokia Antwerp BE Email: gunter.van_de_velde@nokia.com Dong, et al. Expires January 9, 2020 [Page 7]