Network Working Group R. Bush Internet-Draft Arrcus & IIJ Intended status: Standards Track K. Patel Expires: May 5, 2020 Arrcus November 2, 2019 L3DL Upper Layer Protocol Configuration draft-ymbk-lsvr-l3dl-ulpc-02 Abstract This document users the Layer 3 Liveness and Discovery protocol to communicate the parameters needed to exchange inter-device Upper Layer Protocol Configuration for upper layer protocols such as the BGP family. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. 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 May 5, 2020. Copyright Notice Copyright (c) 2019 IETF Trust and the persons identified as the document authors. All rights reserved. Bush & Patel Expires May 5, 2020 [Page 1] Internet-Draft L3DL Upper Layer Protocol Configuration November 2019 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. Reading and Terminology . . . . . . . . . . . . . . . . . . . 2 3. Upper Layer Protocol Configuration PDU . . . . . . . . . . . 3 3.1. BGP ULPC Attribute sub-TLVs . . . . . . . . . . . . . . . 3 3.1.1. BGP ASN . . . . . . . . . . . . . . . . . . . . . . . 4 3.1.2. BGP IPv4 Address . . . . . . . . . . . . . . . . . . 5 3.1.3. BGP IPv6 Address . . . . . . . . . . . . . . . . . . 5 3.1.4. BGP Authentication sub-TLV . . . . . . . . . . . . . 5 3.1.5. BGP Miscellaneous Flags . . . . . . . . . . . . . . . 6 4. Security Considerations . . . . . . . . . . . . . . . . . . . 6 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 6.1. Normative References . . . . . . . . . . . . . . . . . . 7 6.2. Informative References . . . . . . . . . . . . . . . . . 8 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 1. Introduction Massive Data Centers (MDCs) which use upper layer protocols such as BGP4, BGP-LS, BGP-SPF, etc. may use the Layer 3 Liveness and Discovery Protocol, L3DP, [I-D.ietf-lsvr-l3dl] to reveal the inter- device links of the topology. It is desirable for devices to facilitate the configuration parameters of those upper layer protocols to enable more hands-free configuration. This document defines a new L3DP PDU to communicate these Upper Layer Protocol Configuration parameters. 2. Reading and Terminology The reader is assumed to have read Layer 3 Discovery and Liveness [I-D.ietf-lsvr-l3dl]. The terminology and PDUs there are assumed here. Familiarity with the BGP4 Protocol [RFC4271] is assumed. Familiarity with BGP-SPF, [I-D.ietf-lsvr-bgp-spf], might be useful. Bush & Patel Expires May 5, 2020 [Page 2] Internet-Draft L3DL Upper Layer Protocol Configuration November 2019 3. Upper Layer Protocol Configuration PDU To communicate parameters required to configure peering and operation of Upper Layer Protocols at IP layer 3 and above, e.g., BGP sessions on a link, a neutral sub-TLV based Upper Layer Protocol PDU is defined 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type = 9 | Payload Length ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ | ULPC Type | AttrCount | ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ Attribute List ... | Sig Type | Signature Len ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ | Signature ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ The Type and Payload Length are defined in [I-D.ietf-lsvr-l3dl]. ULPC Type: An integer denoting the type of the uper layer protocol 0 : Reserved 1 : BGP 2-255 : Reserved The AttrCount is the number of attribute sub-TLVs in the Attribute List. The Attribute List is a, possibly null, set of sub-TLVs describing the configuration attributes of the specific upper layer protocol. An Attribute consists of a one octet Attribute Type, a one octet Attribute Length of the number of octets in the Attribute, and a Payload of arbitrary length up to 253 octets. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Attr Type = 1 | Attr Len | Payload | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3.1. BGP ULPC Attribute sub-TLVs The parameters needed for BGP peering on a link are exchanged in sub- TLVs within an Upper Layer Protocol PDU. The following describe the various sub-TLVs for BGP. Bush & Patel Expires May 5, 2020 [Page 3] Internet-Draft L3DL Upper Layer Protocol Configuration November 2019 The goal is to provide the minimal set of configuration parameters needed by BGP OPEN to successfully start a BGP peering. The goal is specifically not to replace or conflict with data exchanged during BGP OPEN. Multiple sources of truth are a recipe for complexity and hence pain. If there are multiple BGP sessions on a link, e.g., IPv4 and IPv6, then multiple sets of BGP sub-TLVs MAY BE exchanged within the BGP ULPC PDU or multiple BGP ULPC PDUs may be sent, one for each address family. A peer receiving BGP ULPC PDUs has only one active BGP ULPC PDU for an particular address family at any point in time; receipt of a new BGP ULPC PDU for a particular address family replaces any previous one. If there are one or more open BGP sessions, receipt of a new BGP ULPC PDU does not affect these sessions and the PDU SHOULD be discarded. If a peer wishes to replace an open BGP session, they must first close the running session and then send a new BGP ULPC PDU. As a link may have multiple encapsulations and multiple addresses for an IP encapsulation, which address of which encapsulation is to be used for the BGP session MUST be specified. For each BGP peering on a link here MUST be one agreed encapsulation, and the addresses used MUST be in the corresponding L3DP IPv4/IPv6 Announcement PDUs. If a peering address has been announced as a loopback, a two or three (one or both ends could be loopbacks) hop BGP session will be established. Otherwise a direct one hop session is used. 3.1.1. BGP ASN The Autonomous System number MUST be specified. If the AS Number is less than 32 bits, it is padded with high order zeros. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Attr Type = 1 | Attr Len = 6 | My ASN ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Bush & Patel Expires May 5, 2020 [Page 4] Internet-Draft L3DL Upper Layer Protocol Configuration November 2019 3.1.2. BGP IPv4 Address The BGP IPv4 Address sub-TLV announces the sender's IPv4 BGP peering source address to be used by the receiver. At least one of IPv4 or IPv6 BGP source addresses MUST be announced. As usual, the BGP OPEN capability negotiation will determine the AFI/ SAFIs to be transported over the peering, see [RFC4760] . 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Attr Type = 2 | Attr Len = 7 | My IPv4 Peering Address ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ | Prefix Len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3.1.3. BGP IPv6 Address The BGP IPv6 Address sub-TLV announces the sender's IPv6 BGP peering source address to be used by the receiver. At least one of IPv4 or IPv6 BGP source addresses MUST be announced. As usual, the BGP OPEN capability negotiation will determine the AFI/ SAFIs to be transported over the peering, see [RFC4760] . 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Attr Type = 3 | Attr Len = 19 | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + + | My IPv6 Peering Address | + + | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | Prefix Len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3.1.4. BGP Authentication sub-TLV The BGP Authentication sub-TLV provides any authentication data needed to OPEN the BGP session. Depending on operator configuration of the environment, it might be a simple MD5 key (see [RFC2385]), the name of a key chain a KARP database (see [RFC7210]), or one of multiple Authentication sub-TLVs to support hop[RFC4808]. Bush & Patel Expires May 5, 2020 [Page 5] Internet-Draft L3DL Upper Layer Protocol Configuration November 2019 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Attr Type = 4 | Attr Len | ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ ~ BGP Authentication Data ... ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3.1.5. BGP Miscellaneous Flags The BGP session OPEN has extensive, and a bit complex, capability negotiation facilities. In case one or more extra attributes might be needed, the BGP Miscellaneous Flags sub-TLV may be used. No flags are currently defined. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Attr Type = 5 | Attr Len = 4 | Misc Flags | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Misc Attrs: Bit 0: Ghu knows what Bit 1-15: Must be zero 4. Security Considerations All the Security considerations of [I-D.ietf-lsvr-l3dl] apply to this PDU. As the ULPC PDU may contain keying material, see Section 3.1.4, it SHOULD BE signed. Any keying material in the PDU SHOULD BE salted ad hashed. The BGP Authentication sub-TLV provides for provisioning MD5, which is a quite weak hash, horribly out of fashion, and kills puppies. But, like it or not, it is what BGP deployments use. 5. IANA Considerations This document requests the IANA create a new entry in the L3DL PDU Type registry as follows: Bush & Patel Expires May 5, 2020 [Page 6] Internet-Draft L3DL Upper Layer Protocol Configuration November 2019 PDU Code PDU Name ---- ------------------- 9 ULPC This document requests the IANA create a registry for L3DL ULPC Type, which may range from 0 to 255. The name of the registry should be L3DL-ULPC-Type. The policy for adding to the registry is RFC Required per [RFC5226], either standards track or experimental. The initial entries should be the following: Value Name ----- ------------------- 0 Reserved 1 BGP 2-255 Reserved 6. References 6.1. Normative References [I-D.ietf-lsvr-l3dl] Bush, R., Austein, R., and K. Patel, "Layer 3 Discovery and Liveness", draft-ietf-lsvr-l3dl-02 (work in progress), July 2019. [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, . [RFC4760] Bates, T., Chandra, R., Katz, D., and Y. Rekhter, "Multiprotocol Extensions for BGP-4", RFC 4760, DOI 10.17487/RFC4760, January 2007, . [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", RFC 5226, DOI 10.17487/RFC5226, May 2008, . Bush & Patel Expires May 5, 2020 [Page 7] Internet-Draft L3DL Upper Layer Protocol Configuration November 2019 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . 6.2. Informative References [I-D.ietf-lsvr-bgp-spf] Patel, K., Lindem, A., Zandi, S., and W. Henderickx, "Shortest Path Routing Extensions for BGP Protocol", draft-ietf-lsvr-bgp-spf-06 (work in progress), September 2019. [RFC2385] Heffernan, A., "Protection of BGP Sessions via the TCP MD5 Signature Option", RFC 2385, DOI 10.17487/RFC2385, August 1998, . [RFC4808] Bellovin, S., "Key Change Strategies for TCP-MD5", RFC 4808, DOI 10.17487/RFC4808, March 2007, . [RFC7210] Housley, R., Polk, T., Hartman, S., and D. Zhang, "Database of Long-Lived Symmetric Cryptographic Keys", RFC 7210, DOI 10.17487/RFC7210, April 2014, . Authors' Addresses Randy Bush Arrcus & IIJ 5147 Crystal Springs Bainbridge Island, WA 98110 US Email: randy@psg.com Keyur Patel Arrcus 2077 Gateway Place, Suite #400 San Jose, CA 95119 United States of America Email: keyur@arrcus.com Bush & Patel Expires May 5, 2020 [Page 8]