Multi-Threaded Routing Toolkit (MRT) Routing Information Export Format with BGP Additional Path Extensions
draft-ietf-grow-mrt-add-paths-03
The information below is for an old version of the document that is already published as an RFC.
Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 8050.
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Authors | Colin Petrie , Thomas King | ||
Last updated | 2017-05-19 (Latest revision 2017-01-14) | ||
Replaces | draft-petrie-grow-mrt-add-paths | ||
RFC stream | Internet Engineering Task Force (IETF) | ||
Intended RFC status | Proposed Standard | ||
Formats | |||
Reviews | |||
Additional resources | Mailing list discussion | ||
Stream | WG state | Submitted to IESG for Publication | |
Document shepherd | Peter Schoenmaker | ||
Shepherd write-up | Show Last changed 2017-01-17 | ||
IESG | IESG state | Became RFC 8050 (Proposed Standard) | |
Action Holders |
(None)
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Consensus boilerplate | Yes | ||
Telechat date | (None) | ||
Responsible AD | Joel Jaeggli | ||
Send notices to | (None) | ||
IANA | IANA review state | IANA OK - Actions Needed | |
IANA action state | RFC-Ed-Ack |
draft-ietf-grow-mrt-add-paths-03
Global Routing Operations C. Petrie Internet-Draft RIPE NCC Intended status: Standards Track T. King Expires: July 18, 2017 DE-CIX January 14, 2017 Multi-Threaded Routing Toolkit (MRT) Routing Information Export Format with BGP Additional Paths Extensions draft-ietf-grow-mrt-add-paths-03 Abstract This document updates the Multi-threaded Routing Toolkit (MRT) export format for Border Gateway Protocol (BGP) routing information by extending it to support the Advertisement of Multiple Paths in BGP extensions. 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 July 18, 2017. Copyright Notice Copyright (c) 2017 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 Petrie & King Expires July 18, 2017 [Page 1] Internet-Draft Additional Paths Extensions in MRT January 2017 the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Rationale . . . . . . . . . . . . . . . . . . . . . . . . . . 2 3. MRT Subtypes for Types BGP4MP/BGP4MP_ET . . . . . . . . . . . 3 4. MRT Subtypes for Type TABLE_DUMP_V2 . . . . . . . . . . . . . 3 4.1. AFI/SAFI specific RIB Subtypes . . . . . . . . . . . . . 3 4.2. RIB_GENERIC_ADDPATH Subtype . . . . . . . . . . . . . . . 4 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 5.1. BGP4MP/BGP4MP_ET Subtype codes: . . . . . . . . . . . . . 4 5.2. TABLE_DUMP_V2 Subtype codes: . . . . . . . . . . . . . . 5 6. Security Considerations . . . . . . . . . . . . . . . . . . . 5 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 7.1. Normative References . . . . . . . . . . . . . . . . . . 5 7.2. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 1. Introduction The MRT record format [RFC6396] was developed to provide researchers and engineers a means to encapsulate, export, and archive routing protocol transactions and routing information base snapshots. The Advertisement of Multiple Paths in BGP [RFC7911] defines a BGP extension to allow the advertisement of multiple paths for the same address prefix without the new paths implicitly replacing any previous ones. This document contains an optional extension to the MRT format [RFC6396] and introduces additional definitions of MRT subtype fields to permit representation of multiple path advertisements [RFC7911]. 2. Rationale MRT parsers are usually stateless. In order to parse BGP messages which contain data structures that depend on the capabilities negotiated during the BGP session setup, the so-called MRT subtypes are utilized. The Advertisement of Multiple Path [RFC7911] extension for BGP alters the encoding of the BGP NLRI format for withdraws and announcements. Therefore new BGP4MP/BGP4MP_ET subtypes as defined in [RFC6396] are required to signal to a MRT parser how to parse the NLRI. In section 4.3 [RFC6396] of the MRT specification RIB subtypes are specified. Prefix length and prefix fields are encoded in the same Petrie & King Expires July 18, 2017 [Page 2] Internet-Draft Additional Paths Extensions in MRT January 2017 manner as the BGP NLRI encoding. In order to support path identifier information as defined in [RFC7911] new subtypes need to be added. The following two sections define the required subtypes. 3. MRT Subtypes for Types BGP4MP/BGP4MP_ET This document defines the following new Subtypes: o BGP4MP_MESSAGE_ADDPATH o BGP4MP_MESSAGE_AS4_ADDPATH o BGP4MP_MESSAGE_LOCAL_ADDPATH o BGP4MP_MESSAGE_AS4_LOCAL_ADDPATH The fields of these message types are identical to the equivalent non-additional-path versions specified in section 4.4 [RFC6396]. These enhancements continues to encapsulate the entire BGP message in the BGP message field. 4. MRT Subtypes for Type TABLE_DUMP_V2 This document defines the following new Subtypes: o RIB_IPV4_UNICAST_ADDPATH o RIB_IPV4_MULTICAST_ADDPATH o RIB_IPV6_UNICAST_ADDPATH o RIB_IPV6_MULTICAST_ADDPATH o RIB_GENERIC_ADDPATH The fields of these message types are identical to the equivalent non-additional-path versions specified in section 4.3 [RFC6396]. However, for the specific case of the 4 AFI/SAFI specific RIB subtypes, the existing RIB Entries field is re-defined as detailed in the sections below. 4.1. AFI/SAFI specific RIB Subtypes In order to preserve the record compaction achieved by using the most common subtypes, and allowing multiple RIB Entries to be stored in a single TABLE_DUMP_V2 record, the existing RIB Entries field is Petrie & King Expires July 18, 2017 [Page 3] Internet-Draft Additional Paths Extensions in MRT January 2017 redefined for use within the new AFI/SAFI specific RIB Subtypes defined by this document as follows: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Peer Index | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Originated Time | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Path Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Attribute Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | BGP Attributes... (variable) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: RIB Entries for AFI/SAFI-specific RIB Subtypes with additional-paths support This adds a field to the RIB Entries record, to store the path identifier, when used with the RIB_IPV4_UNICAST_ADDPATH, RIB_IPV4_MULTICAST_ADDPATH, RIB_IPV6_UNICAST_ADDPATH and RIB_IPV6_MULTICAST_ADDPATH subtypes. 4.2. RIB_GENERIC_ADDPATH Subtype The fields of this subtype are identical to the equivalent non- additional-path versions specified in section 4.3.3 [RFC6396]. These fields continue to encapsulate the raw and additional-path enabled AFI/SAFI/NLRI in the record, and the raw attributes in the RIB Entries. For clarity, the RIB Entries in this subtype are not redefined. 5. IANA Considerations This document requests that IANA assign the following subtype codes to the MRT name space [1]: 5.1. BGP4MP/BGP4MP_ET Subtype codes: BGP4MP_MESSAGE_ADDPATH = 8 (Section 3) BGP4MP_MESSAGE_AS4_ADDPATH = 9 (Section 3) BGP4MP_MESSAGE_LOCAL_ADDPATH = 10 (Section 3) Petrie & King Expires July 18, 2017 [Page 4] Internet-Draft Additional Paths Extensions in MRT January 2017 BGP4MP_MESSAGE_AS4_LOCAL_ADDPATH = 11 (Section 3) The values provided above are suggested as they are used in implementations. 5.2. TABLE_DUMP_V2 Subtype codes: RIB_IPV4_UNICAST_ADDPATH = 8 (Section 4.1) RIB_IPV4_MULTICAST_ADDPATH = 9 (Section 4.1) RIB_IPV6_UNICAST_ADDPATH = 10 (Section 4.1) RIB_IPV6_MULTICAST_ADDPATH = 11 (Section 4.1) RIB_GENERIC_ADDPATH = 12 (Section 4.2) The values provided above are suggested as they are used in implementations. 6. Security Considerations It is not believed that this document adds any additional security considerations. However, the security considerations of [RFC6396] are equally applicable to this document, and this document permits the export of more detailed routing data. An organization that uses the MRT format to store their BGP routing information should be aware that supporting these extensions permits more detailed network path information to be stored, and should consider the implications of this within their environment. An organization that peers with public BGP collectors, and enables the additional-paths capability on a peering session, should be aware that it is exporting not only its best paths, but potentially other paths within its networks. The BGP peer should consider any and all implications of exposing this additional data. 7. References 7.1. Normative References [RFC6396] Blunk, L., Karir, M., and C. Labovitz, "Multi-Threaded Routing Toolkit (MRT) Routing Information Export Format", RFC 6396, DOI 10.17487/RFC6396, October 2011, <http://www.rfc-editor.org/info/rfc6396>. Petrie & King Expires July 18, 2017 [Page 5] Internet-Draft Additional Paths Extensions in MRT January 2017 [RFC7911] Walton, D., Retana, A., Chen, E., and J. Scudder, "Advertisement of Multiple Paths in BGP", RFC 7911, DOI 10.17487/RFC7911, July 2016, <http://www.rfc-editor.org/info/rfc7911>. 7.2. URIs [1] https://www.iana.org/assignments/mrt/mrt.xhtml Authors' Addresses Colin Petrie RIPE NCC Stationsplein 11 Amsterdam 1012 AB NL Email: cpetrie@ripe.net Thomas King DE-CIX Management GmbH Lichtstrasse 43i Cologne 50825 Germany Email: thomas.king@de-cix.net Petrie & King Expires July 18, 2017 [Page 6]