LISP Site External Connectivity
draft-jain-lisp-site-external-connectivity-01

Network Working Group                                            P. Jain
Internet-Draft                                                 V. Moreno
Intended status: Experimental                                   S. Hooda
Expires: November 3, 2020                                  Cisco Systems
                                                             May 2, 2020

                    LISP Site External Connectivity
             draft-jain-lisp-site-external-connectivity-01

Abstract

   This draft defines how to register/retrieve default-pETR mapping
   information in LISP when the destination is not registered/known to
   the local site and its mapping system (e.g. the destination is an
   internet or external site destination).

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
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   This Internet-Draft will expire on November 3, 2020.

Copyright Notice

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   This document is subject to BCP 78 and the IETF Trust's Legal
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   (https://trustee.ietf.org/license-info) in effect on the date of

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   publication of this document.  Please review these documents
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Definition of Terms . . . . . . . . . . . . . . . . . . . . .   3
   3.  pETR Registration/Notification  . . . . . . . . . . . . . . .   3
   4.  pETR Request/Resolution . . . . . . . . . . . . . . . . . . .   3
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   4
   8.  Normative Reference . . . . . . . . . . . . . . . . . . . . .   4
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   5

1.  Introduction

   The LISP architecture and protocol [I-D.ietf-lisp-rfc6833bis]
   introduces two types of replies to a map-request sent by an ITR:

   - when the EID is known or registered to the mapping system, a
   regular map-reply with mapping information is sent, or

   - when the EID is unknown or known but not registered, a negative-
   map-reply (NMR) is sent.

   Currently the NMR does not convey pETR RLOC-set information to
   specify where the ITR should send the packet.

   This document describes how to use the LISP messages to register and
   provide pETR RLOC-set information for destinations which are EIDs not
   registered with the Mapping System, or simply are "not known" to be
   an existing EID.  These destinations could be the destinations which
   are outside of the LISP site belonging to non-LISP domains, hence are
   not registered with the LISP Mapping System.

   The reachability of these destinations can be provided either by
   configuring pETR information directly into the Mapping System, or by
   the registration done by certain pETRs.  The pETR registration is
   specifically useful when the traffic to these external destinations
   needs to be sent encapsulated to a preferred pETR/gateway chosen
   dynamically.  This mechanism also helps to achieve faster
   convergence.

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   This document also specifies the structure of the map-reply
   containing pETR RLOC-set information.

2.  Definition of Terms

   Same as defined in [I-D.ietf-lisp-rfc6833bis].

3.  pETR Registration/Notification

   pETRs having external or internet connectivity MAY register the pETR
   with the mapping system.  The pETR Map-Register/Map-Notify procedures
   and record format are the same as in [I-D.ietf-lisp-rfc6833bis] with
   the following contents:

   - An "EID-Prefix" as an agreed upon or configurable "Distinguished
   Name" according to [I-D.farinacci-lisp-name-encoding].

   - RLOC-set for pETR information.

   - Each locator in the RLOC-set MAY be encoded as per [I-D.ietf-lisp-
   vpn].  This enables dynamic external connectivity in VPN
   environments.

   - Additional information MAY be encoded in vendor specific LCAF type
   [I-D.ietf-lisp-vendor-lcaf] about the registering pETR such as its
   performance matrix, resource availability for the Mapping System to
   make preference decision.

4.  pETR Request/Resolution

   The Map-Request procedures and record format are the same as in [I-
   D.ietf-lisp-rfc6833bis].

   When the Map-Server (or ETR) determines that the requested
   destination is external or unknown to the mapping system, it sends a
   Map-Reply containing the pETR information.  The Map-Reply procedures
   and record format are the same as described in the Map-Server
   processing section of [I-D.ietf-lisp-rfc6833bis].  This Map-Reply has
   the following content (as defined per regular map-reply and negative-
   map-reply in [I-D.ietf-lisp-rfc6833bis]):

   - An EID-Prefix calculated as non-LISP "hole" per the procedures in
   [I-D.ietf-lisp-rfc6833bis] for negative map-reply.

   - RLOC count MUST be non-zero.

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   - Each locator in the RLOC-set MAY be encoded as per [I-D.ietf-lisp-
   vpn].  This enables dynamic external connectivity in VPN
   environments.

   - TTL MAY be shorter than regular map-reply.

   - Additional information MAY be encoded in vendor specific LCAF type
   [I-D.ietf-lisp-vendor-lcaf] about the mapping such as whether the
   mapping is based upon policy or registration.

5.  IANA Considerations

   No IANA considerations apply to this document.

6.  Security Considerations

   There are no additional security considerations except what already
   discussed in [I-D.ietf-lisp-rfc6833bis].

7.  Acknowledgements

   The authors would like to thank Fabio Maino for the suggestions and
   review of this document.

8.  Normative Reference

   [I-D.farinacci-lisp-name-encoding]
              Farinacci, D., "LISP Distinguished Name Encoding", draft-
              farinacci-lisp-name-encoding-07 (work in progress), March
              2019.

   [I-D.ietf-lisp-rfc6833bis]
              Farinacci, D., Maino, F., Fuller, V., and A. Cabellos-
              Aparicio, "Locator/ID Separation Protocol (LISP) Control-
              Plane", draft-ietf-lisp-rfc6833bis-25 (work in progress),
              June 2019.

   [I-D.ietf-lisp-vendor-lcaf]
              Rodriguez-Natal, A., Ermagan, V., Smirnov, A., Ashtaputre,
              V., and D. Farinacci, "Vendor Specific LISP Canonical
              Address Format (LCAF)", draft-ietf-lisp-vendor-lcaf-05
              (work in progress), September 2019.

   [I-D.ietf-lisp-vpn]
              Moreno, V. and D. Farinacci, "LISP Virtual Private
              Networks (VPNs)", draft-ietf-lisp-vpn-04 (work in
              progress), May 2019.

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   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

Authors' Addresses

   Prakash Jain
   Cisco Systems
   San Jose, CA
   USA

   Email: prakjain@cisco.com

   Victor Moreno
   Cisco Systems
   San Jose, CA
   USA

   Email: vimoreno@cisco.com

   Sanjay Hooda
   Cisco Systems
   San Jose, CA
   USA

   Email: shooda@cisco.com

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