Internet DRAFT - draft-rodrigueznatal-lisp-multi-tuple-eids
draft-rodrigueznatal-lisp-multi-tuple-eids
LISP Working Group A. Rodriguez-Natal
Internet-Draft Cisco Systems
Intended status: Experimental A. Cabellos-Aparicio
Expires: 14 April 2022 Technical University of Catalonia
S. Barkai
Nexar Inc.
V. Ermagan
Google
D. Lewis
F. Maino
Cisco Systems
D. Farinacci
lispers.net
11 October 2021
LISP support for Multi-Tuple EIDs
draft-rodrigueznatal-lisp-multi-tuple-eids-12
Abstract
This document describes extensions for LISP to support EIDs based on
tuples of multiple elements.
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 14 April 2022.
Copyright Notice
Copyright (c) 2021 IETF Trust and the persons identified as the
document authors. All rights reserved.
Rodriguez-Natal, et al. Expires 14 April 2022 [Page 1]
Internet-Draft LISP-Multi-Tuple-EIDs October 2021
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
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 2
2. Definition of terms . . . . . . . . . . . . . . . . . . . . . 3
3. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Protocol Operation with Extended-EIDs . . . . . . . . . . . . 3
4.1. LISP Tunnel Routers . . . . . . . . . . . . . . . . . . . 4
4.2. Mapping System . . . . . . . . . . . . . . . . . . . . . 4
5. Extended-EIDs Encoding . . . . . . . . . . . . . . . . . . . 5
5.1. 5-Tuple . . . . . . . . . . . . . . . . . . . . . . . . . 5
6. Extended-EID Lookups . . . . . . . . . . . . . . . . . . . . 5
6.1. 5-Tuple (Coarse) . . . . . . . . . . . . . . . . . . . . 5
6.2. 5-Tuple (Exact) . . . . . . . . . . . . . . . . . . . . . 6
7. Mapping Databases for Extended-EIDs . . . . . . . . . . . . . 7
7.1. 5-Tuple (Coarse) . . . . . . . . . . . . . . . . . . . . 7
7.2. 5-Tuple (Exact) . . . . . . . . . . . . . . . . . . . . . 7
8. A Note on Instance-ID . . . . . . . . . . . . . . . . . . . . 7
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 7
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
11. Security Considerations . . . . . . . . . . . . . . . . . . . 7
12. Normative References . . . . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction
This document describes how LISP handles lookups based on Extended-
EIDs, i.e. tuples of n elements. Particularly it describes how the
Tunnel Routers and the Mapping System operate when Extended-EIDs are
in place, the different types of Extended-EIDs defined so far, how
the lookup is performed for each Extended-EID type and which mapping
databases are recommended to use depending on the kind of Extended-
EIDs used.
1.1. 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].
Rodriguez-Natal, et al. Expires 14 April 2022 [Page 2]
Internet-Draft LISP-Multi-Tuple-EIDs October 2021
2. Definition of terms
* n-tuple: The term n-tuple is used in this document to describe the
set of n elements present in a data packet (e.g. IP address,
port, protocol) that can be used to identify unequivocally a
packet or a set of packets.
* 5-tuple: The term 5-tuple is used in this document to describe the
set comprised by 5 elements, being these the source IP address,
the destination IP address, the level 4 protocol number, the level
4 protocol source port and the level 4 protocol destination port
of a data packet.
* Extended-EID: This document uses the term Extended-EID to refer to
any n-tuple (including a 5-tuple) used in a EID role. See as well
[RFC8111]
* Flow: The term flow is used in this document to refer to the
sequence of packets identified by the same n-tuple.
* MT-[xTR, RTR, MS, MR]: A LISP [xTR, RTR, MS, MR] that supports the
enhanced operation for Multi-Tuple Extended-EIDs described in this
document.
* MT-TR: A LISP tunnel router (e.g. xTR, RTR) that supports the
enhanced operation for Multi-Tuple Extended-EIDs described in this
document, e.g. MT-xTR, MT-RTR.
The rest of the terms are defined in their respective documents. See
the LISP specification [I-D.ietf-lisp-rfc6833bis] for most of the
definitions, [RFC8060] for LCAF and [I-D.ietf-lisp-te] for RTR.
3. Overview
This document describes extensions for LISP to support Multi-Tuple
Extended-EIDs. Protocol operation follows the specification defined
on [I-D.ietf-lisp-rfc6833bis] except for the following. Besides of
IP mappings, a Mapping System can store Extended-EID mappings. Being
Extended-EID a n-tuple identifying a flow. LISP routers perform
look-ups based on these Extended-EIDs, instead of on destination IPs.
Apart from using n-tuples instead of IPs, retrieving information from
the Mapping System follows LISP standard mechanisms (i.e. Map-
Request, Map-Reply).
4. Protocol Operation with Extended-EIDs
Rodriguez-Natal, et al. Expires 14 April 2022 [Page 3]
Internet-Draft LISP-Multi-Tuple-EIDs October 2021
4.1. LISP Tunnel Routers
LISP tunnel routers with enhanced operation for Multi-Tuple Extended-
EIDs, or MT-TRs (MT-xTRs and MT-RTRs), behave as specified on and
[I-D.ietf-lisp-rfc6833bis], with the particularity that MT-TRs
perform mapping lookups based on Extended-EIDs (n-tuples).
Any MT-TR must keep an internal map-cache indexed by Extended-EIDs.
When a MT-TR receives a packet to encapsulate, it extracts the fields
required by the n-tuple lookup in use and stores them in an Extended-
EID structure. In the case of a 5-tuple lookup, it will extract the
source address, destination address, level 4 protocol, source port
(if any) and destination port (if any) from the packet. The MT-TR
uses the Extended-EID to perform a look-up into the map-cache. The
lookup process must follow the procedure described in section
Section 6. If there is an entry on the map-cache that matches the
Extended-EID, the MT-TR retrieves the mapping information, selects a
destination RLOC and encapsulates the packet, as defined in
[I-D.ietf-lisp-rfc6833bis]
If the map-cache of the MT-TR contains no entry for the Extended-EID,
the MT-TR sends a Map-Request to a MT-MR. The MT-TR MUST be
provisioned with the RLOC of at least one MT-MR. The Map-Request
sent carries the Extended-EID (encoded in the specific LCAF for that
Extended-EID type) in the EID-prefix field of the Map-Request. This
Map-Request will eventually trigger a Map-Reply to be sent back the
requester MT-TR, see section Section 4.2. This Map-Reply carries an
Extended-EID on the EID-prefix field. The MT-TR stores, as defined
in [I-D.ietf-lisp-rfc6833bis], the mapping for the Extended-EID.
4.2. Mapping System
Mapping System elements (comprising Map Servers and Map Resolvers)
behave as specified on [I-D.ietf-lisp-rfc6833bis] when implementing
enhanced Multi-Tuple Extended-EIDs operation, with the particularity
that MT-MRs resolve Map-Requests based on Extended-EIDs and MT-MSs
store mappings indexed by Extended-EIDs.
MT-MRs must be capable of processing Map-Requests with an Extended-
EID on the EID-prefix field, of finding the appropriate MT-MS for the
Extended-EID and of forwarding the Map-Request to it. This is done
according to the lookup rules described in section Section 6 and
using the mapping database described in section Section 7 which
differs depending on the specific Extended-EID.
LISP elements must perform the mapping update mechanisms defined in
[I-D.ietf-lisp-rfc6833bis] (e.g, SMR) using as EID the Extended-EID.
Rodriguez-Natal, et al. Expires 14 April 2022 [Page 4]
Internet-Draft LISP-Multi-Tuple-EIDs October 2021
5. Extended-EIDs Encoding
This section describes the Extended-EID types defined so far and the
LCAFs to support them.
5.1. 5-Tuple
The 5-tuple LCAF is a combination of Application Data Type 4 and
Source/Dest Type 12 LCAFs. Experimental deployment may indicate that
a specific 5-tuple type LCAF is necessary.
6. Extended-EID Lookups
This section describes the lookup process to be followed when using
Extended-EID. At this point, this document only covers 5-tuple kind
of Extended-EID lookups (with options for coarse or exact lookup).
It is expected to include lookup mechanism for n-tuple lookups with
more complex protocol combinations.
6.1. 5-Tuple (Coarse)
When using a coarse lookup for 5-tuple, the encoding described in
Section 5.1 is used to carry the Extended-EID. Note that a coarse
lookup also covers exact lookups. The lookup is (logically) done at
steps, one per each element of the tuple. The lookup MUST follow
this strict order:
(1) Destination address
(2) Source address
(3) Protocol number
(4) Destination port
(5) Source port
This means that for a given 5-tuple, the lookup process will first
select from the available 5-tuples present in the system, the ones
that match the destination address. Among them, those that also
match the source address. This is iterated for the rest of the
elements in the tuple. If a 5-tuple matches several entries, then
the one with the longest prefix match or shortest port-range has
priority. To clarify the process an example is provided below.
Suppose that a MT-MS stores the mappings indexed by the tuples (A),
(B), (C), (D) and (E), and that it receives Map-Request messages
carrying the Extended-EIDs (T), (U), (V), (W), (X) and (Y).
Rodriguez-Natal, et al. Expires 14 April 2022 [Page 5]
Internet-Draft LISP-Multi-Tuple-EIDs October 2021
dst-add src-add pr dst-prt src-prt
(A) [1.1.1.0/24, 2.2.0.0/16, 17, 1000-3000, 1000-3000]
(B) [1.1.0.0/16, 2.2.2.0/24, 17, 1000-3000, 1000-3000]
(C) [3.3.3.0/24, 4.4.4.0/24, 6, 4000-4500, 7000-8000]
(D) [3.3.3.0/24, 4.4.4.0/24, 6, 4000-6000, 7000-8000]
(E) [5.5.5.0/24, 6.6.6.0/24, 17, 0-65535, 0-65535]
(T) [ 1.1.1.8, 2.2.2.9, 17, 2000, 2000 ]
(U) [ 1.1.8.8, 2.2.9.9, 17, 2000, 2000 ]
(V) [ 1.1.8.8, 2.2.2.9, 17, 2000, 2000 ]
(W) [ 3.3.3.3, 4.4.4.4, 6, 4300, 7500 ]
(X) [ 3.3.3.3, 4.4.4.4, 6, 5000, 7500 ]
(Y) [ 5.5.5.5, 6.6.6.6, 17, 6000, 6000 ]
Figure 1: 5-tuple example for coarse lookup
(1) When (T) is Map-Requested, the lookup could match both (A) and
(B), however destination address has preference over source
address and therefore (A) is returned.
(2) When (U) is Map-Requested, the lookup will return that no entry
exists for the 5-tuple.
(3) When (V) is Map-Requested, the lookup will return (B).
(4) When (W) is Map-Requested, the lookup will return (C) and not
(D), although both could match the tuple, since the destination
port range is shorter in (C).
(5) When (X) is Map-Requested, the lookup will return (D).
(6) When (Y) is Map-Requested, the lookup will return (E). A port
range of 0-65535 means any port.
6.2. 5-Tuple (Exact)
In scenarios where 5-tuple coarse lookup is not required, the lookup
can be optimized to only account for exact matchs. When using a
exact lookup for 5-tuple, the encoding described in Section 6.1 is
used to carry the Extended-EID. The exact match lookup is performed
by serializing the elements of the 5-tuple as a single vector of
bits. The order to serialize the elements is the same that is
described in Section 5.1 This (unique) vector of bits is then used as
the key to perform a exact match lookup over the available entries.
Rodriguez-Natal, et al. Expires 14 April 2022 [Page 6]
Internet-Draft LISP-Multi-Tuple-EIDs October 2021
7. Mapping Databases for Extended-EIDs
The mapping database, i.e. the system to interconnect (MT-)MRs and
(MT-)MSs should be optimal for each one of the different Extended-
EIDs types. This section covers recommended mapping databases for
each of the Extended-EIDs described in this document.
7.1. 5-Tuple (Coarse)
The mapping database to be used for a coarse lookup of 5-tuples can
leverage on the LISP-DDT mapping database [RFC8111] since it supports
multi-tuple lookups. Note that a LISP-DDT based database can support
also a exact lookup.
7.2. 5-Tuple (Exact)
Although a LISP-DDT based mapping database supports both coarse and
exact lookups, the particularities of the latter benefit of using a
mapping database optimized for flat namespaces rather than one
optimized for hierarchical data. In that sense, the exact match
mechanism should be supported by a DHT-like mapping database, such
[I-D.cheng-lisp-shdht] or [LISP-DHT].
8. A Note on Instance-ID
Instance-ID is a special case to be considered. If it is in use, its
lookup is resolved before the lookup for the Extended-EID begins
(regardless of the Extended-EID type). In terms of implementation
this means that if the Instance-ID is present, it will have always
more priority that any other field within the multi-tuple EID. In
other words, Instance-ID is the high-order parts of the destination
and source addresses and a longest match lookup should be applied to
it before looking up the address itself.
9. Acknowledgments
10. IANA Considerations
This memo includes no request to IANA.
11. Security Considerations
Security Considerations TBD
12. Normative References
Rodriguez-Natal, et al. Expires 14 April 2022 [Page 7]
Internet-Draft LISP-Multi-Tuple-EIDs October 2021
[I-D.cheng-lisp-shdht]
Cheng, L. and M. Sun, "LISP Single-Hop DHT Mapping
Overlay", Work in Progress, Internet-Draft, draft-cheng-
lisp-shdht-04, 15 July 2013,
<https://www.ietf.org/archive/id/draft-cheng-lisp-shdht-
04.txt>.
[I-D.ietf-lisp-rfc6833bis]
Farinacci, D., Maino, F., Fuller, V., and A. Cabellos,
"Locator/ID Separation Protocol (LISP) Control-Plane",
Work in Progress, Internet-Draft, draft-ietf-lisp-
rfc6833bis-30, 18 November 2020,
<https://www.ietf.org/archive/id/draft-ietf-lisp-
rfc6833bis-30.txt>.
[I-D.ietf-lisp-te]
Farinacci, D., Kowal, M., and P. Lahiri, "LISP Traffic
Engineering Use-Cases", Work in Progress, Internet-Draft,
draft-ietf-lisp-te-09, 19 September 2021,
<https://www.ietf.org/archive/id/draft-ietf-lisp-te-
09.txt>.
[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>.
[RFC8060] Farinacci, D., Meyer, D., and J. Snijders, "LISP Canonical
Address Format (LCAF)", RFC 8060, DOI 10.17487/RFC8060,
February 2017, <https://www.rfc-editor.org/info/rfc8060>.
[RFC8111] Fuller, V., Lewis, D., Ermagan, V., Jain, A., and A.
Smirnov, "Locator/ID Separation Protocol Delegated
Database Tree (LISP-DDT)", RFC 8111, DOI 10.17487/RFC8111,
May 2017, <https://www.rfc-editor.org/info/rfc8111>.
Authors' Addresses
Alberto Rodriguez-Natal
Cisco Systems
170 Tasman Drive
San Jose, CA
United States of America
Email: natal@cisco.com
Rodriguez-Natal, et al. Expires 14 April 2022 [Page 8]
Internet-Draft LISP-Multi-Tuple-EIDs October 2021
Albert Cabellos-Aparicio
Technical University of Catalonia
Barcelona
Spain
Email: acabello@ac.upc.edu
Sharon Barkai
Nexar Inc.
CA
United States of America
Email: sharon.barkai@getnexar.com
Vina Ermagan
Google
United States of America
Email: ermagan@gmail.com
Darrel Lewis
Cisco Systems
170 Tasman Drive
San Jose, CA
United States of America
Email: darlewis@cisco.com
Fabio Maino
Cisco Systems
170 Tasman Drive
San Jose, CA
United States of America
Email: fmaino@cisco.com
Dino Farinacci
lispers.net
San Jose, CA
United States of America
Email: farinacci@gmail.com
Rodriguez-Natal, et al. Expires 14 April 2022 [Page 9]
