Internet DRAFT - draft-boucadair-lisp-idr-ms-discovery
draft-boucadair-lisp-idr-ms-discovery
Network Working Group M. Boucadair
Internet-Draft C. Jacquenet
Intended status: Experimental Orange
Expires: September 10, 2016 March 9, 2016
LISP Mapping Service Discovery at Large
draft-boucadair-lisp-idr-ms-discovery-01
Abstract
Locator/ID Separation Protocol (LISP) operation relies upon a mapping
mechanism that is used by ingress/egress Tunnel Routers (xTR) to
forward traffic over the LISP network. The ability of dynamically
discovering the Map-Resolver and Map-Server entities that provide
such mapping services is meant to facilitate global LISP operation
(automatic discovery of Map-Resolvers and Map-Servers).
This document specifies a BGP Extended Communities attribute that can
be used to dynamically discover LISP Mapping Systems of different
domains.
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
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Internet-Drafts are draft documents valid for a maximum of six months
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on September 10, 2016.
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Copyright Notice
Copyright (c) 2016 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
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Rationale . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. LISP Mapping System Target BGP Extended Community . . . . . . 5
4. Security Considerations . . . . . . . . . . . . . . . . . . . 6
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 6
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
7.1. Normative references . . . . . . . . . . . . . . . . . . 7
7.2. Informative references . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
Locator/ID Separation Protocol (LISP, [RFC6830] ) operation relies
upon a mapping mechanism that is used by ingress/egress Tunnel
Routers (xTR) to forward traffic over the LISP network. The ability
of dynamically discovering the Map-Resolver and Map-Server entities
that provide such mapping services is meant to facilitate global LISP
operation (automatic discovery of Map-Resolvers and Map-Servers).
Within this document, a Mapping System provides the LISP mapping
service [RFC6833]. Map-Resolvers, Map-Servers, and other components
may be part of a Mapping System such as authorization, subscription
profiles, etc. These components are considered as black boxes; only
the external behavior of the Mapping System is in scope.
Distinct LISP mapping systems may emerge if LISP users or network
operators who solicit or manage the Mapping System want to avoid some
region-centric systems, for example, or if they want to position
themselves as a core provider of the Mapping System. The lack of
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clear policies of the management and operation of the LISP Mapping
Systems may encourage such practices.
This document assumes a hierarchy in the Mapping System organisation
for business, governance, control, and regulatory purposes in
particular. In such contexts, the document assumes that a Mapping
System may maintain a portion of or a global mapping table.
Because of its experimental nature of LISP and the various platforms
LISP operation relies upon (like the platforms used by the LISP
mapping systems) should encourage innovation by testing new services
that may take advantage of LISP in inter-domain deployment scenarios
without requiring the participation of all LISP-enabled domains.
Such approach is also meant to avoid any risk of freezing LISP
developments.
Because the design and operation of a consistent Mapping System is
critical for the adoption of LISP at large scale, this document
advocates for means to dynamically discover other Mapping Systems
that are open to cooperate in inter-domain LISP deployment scenarios,
typically .
Deploying LISP for inter-domain use cases may raise the following
issues:
Issue#1: A LISP domain may need to discover available Mapping
Systems so that it can rely upon them to extend the reachability
scope.
Issue#2: Various Mapping Systems can be deployed over the Internet.
These Mapping Systems need to interconnect to extend the
reachability scope and avoid pressure on PTR (Proxy Tunnel Router)
devices. Also, various Mapping Systems encourage the enforcement
of policies that aim at optimizing LISP forwarding: for example,
policies that consist in avoiding the solicitation of specific
domains/ASes.
Issue#3: Distinct flavors of Mapping Systems may be deployed.
These mappings may not rely on the same database mapping system
(e.g., NERD, ALT, CONS, etc.). As such, a clear interface to ease
interconnection between these realms is needed. Standard
solutions to discover Mapping Systems capabilities are likely to
ease the interconnection of Mapping Systems.
Issue#4: Security concerns may arise during the discovery of the
available Mapping Systems: for example, a given Mapping System may
deny access from another domain, or available Mapping Systems need
to make sure that they are entitled to exchange information with
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one another or that an xTR of a given LISP network is entitled to
solicit a mapping system of another LISP network, etc.
An efficient and scalable deployment of LISP within an inter-domain
context for traffic engineering purposes, in particular, relies
heavily on the availability of an inter-domain mapping system that
spans several domains. From this perspective, the success of a
global LISP adoption and deployment will mainly depend on how LISP-
enabled domains will graft to existing mapping systems that can
guarantee a global reachability scope. To minimize the risk of a
fragmented Mapping System that would jeopardize the overall
efficiency of an inter-domain LISP routing system, there is a need to
encourage and facilitate the coordination of participating Mapping
Systems.
This document relies on extended BGP communities [RFC4360] to
advertise that a given domain supports the LISP Mapping Service. A
contact IPv4 address and/or IPv6 address are also included in the
attribute so that remote LISP Mapping Systems or LISP domains may
initiate negotiation cycles for the sake of LISP Mapping System
Interconnection or subscription to the Mapping Service offered by
that Mapping System.
Section 3 specifies a solution for the discovery of LISP Mapping
Systems that are deployed in distinct administrative domains. This
BGP-based solution assumes that domains that support a LISP Mapping
Service will use the BGP Extended Communities attribute to inform
other domains about the support of the service. EIDs that can be
serviced with LISP will be tagged accordingly. Note that an EID can
be serviced by multiple Mapping Systems. Remote LISP Mapping Systems
will rely upon that BGP-based advertising capability to discover the
existence and the status of other Mapping Systems. Once a Mapping
System is discovered, a local Mapping System can establish an
interconnection agreement with that remote Mapping System. The
contact IP address provided as part of the BGP Extended Communities
attribute will be used to contact a remote Mapping System to request
for further LISP-related capabilities, possibly negotiate an
interconnection agreement and, consequently, extend the scope of the
networks that can be serviced using LISP. Also, leaf LISP-aware
networks can rely upon the information carried in the BGP Extended
Communities attribute to discover Mapping Systems that may be
solicited to invoke their mapping service. Subscription cycles may
then be considered.
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2. Rationale
This document focuses on the discovery of LISP Mapping Systems that
are deployed in distinct administrative domains.
The rationale is as follows:
1. Announce: Domains that support a LISP Mapping Service will use
the BGP Extended Communities attribute (Section 3) to inform
other domains about the support of the service. EIDs that can be
serviced with LISP can be tagged accordingly. Note that an EID
can be serviced by multiple Mapping Systems.
2. Discover: Remote LISP Mapping Systems will rely upon that BGP-
based advertising capability (Section 3) to discover the
existence of other Mapping Systems.
3. Negotiate/Interconnect/Invoke: The contact IP address provided as
part of the BGP Extended Communities attribute (Section 3) will
be used to contact a remote Mapping System to request for further
LISP-related capabilities, possibly negotiate an interconnection
agreement and, consequently, extend the scope of the networks
that can be serviced using LISP.
4. Negotiate/Subscribe/Invoke: Also, leaf LISP-aware networks can
rely upon the information carried in the BGP Extended Communities
attribute to discover Mapping Systems that may be solicited to
invoke their mapping service. Subscription cycles may then be
considered.
Only the first two steps are in scope of this document; the remaining
steps can be achieved by other means such as
[I-D.boucadair-connectivity-provisioning-protocol].
3. LISP Mapping System Target BGP Extended Community
The LISP Mapping System Target Community identifies one or more
Mapping System contact points that can receive mapping system
interconnect and/or subscription requests. These contact points are
identified with IPv4 and/or IPv6 addresses.
The LISP Mapping System Target Community is of an extended type. As
such, the behavior specified in Section 6 of [RFC4360] applies to the
LISP Mapping System Target Community.
The presence of this community is an explicit indication that
associated networks can be managed by a LISP Mapping System that is
reachable at the addresses carried in the attribute.
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This document reuses the Transitive IPv4-Address-Specific Extended
Community [RFC4360] and Transitive IPv6-Address-Specific Extended
Community [RFC5701] for the purpose of this document. Dedicated sub-
types are to be allocated (see Section 5).
The Global Administrator field MUST be set to an IP address of the
Mapping System. This address MUST be configured on the originating
BGP speaker.
The "Local Administrator" field of the LISP Mapping System Target
Community is used to encode an identifier of the Mapping System.
Considerations about the assignment of globally unique identifiers to
LISP Mapping Systems are out of scope. A configurable parameter may
be supported by BGP implementations to provide the value carried in
the "Local Administrator" field. If no identifier is configured on
the originating BGP speaker, the "Local Administrator" field MUST be
set to 0.
4. Security Considerations
This document does not introduce any additional security issues other
than those discussed in [RFC4360] and [RFC5701].
5. IANA Considerations
According to [RFC7153], this document requests the assignment of a
sub-type in the "0x00-0xbf" range from the Transitive IPv4-Address-
Specific Extended Community Sub-Types registry available at
http://www.iana.org/assignments/bgp-extended-communities/bgp-
extended-communities.xml#trans-ipv4:
Type Value Name Reference
TBA LISP Mapping System Target [This-Document]
Also, this document requests the assignment of a sub-type from the
Transitive IPv6-Address-Specific Extended Community Types registry
available at http://www.iana.org/assignments/bgp-extended-
communities/bgp-extended-communities.xml#trans-ipv6:
Type Value Name Reference
TBA LISP Mapping System Target [This-Document]
6. Acknowledgments
This work is partly funded by ANR LISP-Lab project #ANR-13-INFR-
009-X.
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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,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC4360] Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended
Communities Attribute", RFC 4360, DOI 10.17487/RFC4360,
February 2006, <http://www.rfc-editor.org/info/rfc4360>.
[RFC5701] Rekhter, Y., "IPv6 Address Specific BGP Extended Community
Attribute", RFC 5701, DOI 10.17487/RFC5701, November 2009,
<http://www.rfc-editor.org/info/rfc5701>.
[RFC6830] Farinacci, D., Fuller, V., Meyer, D., and D. Lewis, "The
Locator/ID Separation Protocol (LISP)", RFC 6830,
DOI 10.17487/RFC6830, January 2013,
<http://www.rfc-editor.org/info/rfc6830>.
[RFC7153] Rosen, E. and Y. Rekhter, "IANA Registries for BGP
Extended Communities", RFC 7153, DOI 10.17487/RFC7153,
March 2014, <http://www.rfc-editor.org/info/rfc7153>.
7.2. Informative references
[I-D.boucadair-connectivity-provisioning-protocol]
Boucadair, M., Jacquenet, C., Zhang, D., and P.
Georgatsos, "Connectivity Provisioning Negotiation
Protocol (CPNP)", draft-boucadair-connectivity-
provisioning-protocol-10 (work in progress), September
2015.
[RFC6833] Fuller, V. and D. Farinacci, "Locator/ID Separation
Protocol (LISP) Map-Server Interface", RFC 6833,
DOI 10.17487/RFC6833, January 2013,
<http://www.rfc-editor.org/info/rfc6833>.
Authors' Addresses
Mohamed Boucadair
Orange
Rennes 35000
France
EMail: mohamed.boucadair@orange.com
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Christian Jacquenet
Orange
Rennes 35000
France
EMail: christian.jacquenet@orange.com
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