Internet DRAFT - draft-jain-lisp-site-external-connectivity
draft-jain-lisp-site-external-connectivity
Network Working Group P. Jain
Internet-Draft Cisco Systems
Intended status: Experimental V. Moreno
Expires: 29 March 2024 Google
S. Hooda
Cisco Systems
26 September 2023
LISP Site External Connectivity
draft-jain-lisp-site-external-connectivity-09
Abstract
This draft defines how to register/retrieve 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
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 29 March 2024.
Copyright Notice
Copyright (c) 2023 IETF Trust and the persons identified as the
document authors. All rights reserved.
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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
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Definition of Terms . . . . . . . . . . . . . . . . . . . . . 3
3. pETR Registration . . . . . . . . . . . . . . . . . . . . . . 3
4. pETR Request/Subscription . . . . . . . . . . . . . . . . . . 3
5. pETR Notification/Publication . . . . . . . . . . . . . . . . 4
6. pETR Resolution . . . . . . . . . . . . . . . . . . . . . . . 4
7. pETR Map-Cache Update . . . . . . . . . . . . . . . . . . . . 5
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
9. Security Considerations . . . . . . . . . . . . . . . . . . . 5
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5
11. Normative Reference . . . . . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction
The LISP architecture and protocol [RFC9301] 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
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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.
This document also specifies the structure of the map-reply
containing pETR RLOC-set information.
2. Definition of Terms
Same as defined in [RFC9300] and [RFC9301].
3. pETR Registration
pETRs having external or internet connectivity MAY register the pETR
with the mapping system per Instance ID (IID) of the VPN [I-D.ietf-
lisp-vpn]. The pETR Map-Register procedures and record format are
the same as in [RFC9301] with the following contents:
- An “EID-Prefix” as configurable "Distinguished Name" defined,
agreed upon and ‘distinguished’ by the mechanism according to [I-
D.ietf-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
[RFC9306] about the registering pETR such as its performance matrix,
location, resource availability for the Mapping System to make
preference decision.
4. pETR Request/Subscription
The Map-Request procedures and record format are the same as in
[RFC9301] with the following contents:
- An "EID-Prefix" MAY be configurable "Distinguished Name" defined,
agreed upon and ‘distinguished’ by the mechanism according to [I-
D.ietf-lisp-name-encoding].
- N-bit MAY be set as per [RFC9437]
- Additional information MAY be encoded in vendor specific LCAF type
[RFC9306] about the requesting ITR such as location, performance
matrix to make preference decision.
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5. pETR Notification/Publication
When pETR registers or updates the pETR registration with the mapping
system, mapping system sends Map-Notify.
With lisp-pubsub [RFC9437], N-bit SHOULD be set in the Map-Request
from ITR. Then, whenever pETR gets updated in the mapping system,
mapping system sends Map-Notify messages to update subscribed ITRs as
per procedures in [RFC9437].
When lisp-pubsub [RFC9437] is not available in the mapping system,
then shorter TTL MAY be used for updating the map-caches at ITR as
per procedures in [RFC9301].
The pETR Map-Notify procedures and record format are the same as in
[RFC9301] with the following contents:
- An "EID-Prefix" as configurable "Distinguished Name" defined,
agreed upon and ‘distinguished’ by the mechanism according to [I-
D.ietf-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.
- TTL MAY be shorter than regular.
- Additional information MAY be encoded in vendor specific LCAF type
[RFC9306] about the registering pETR such as its performance matrix,
location, resource availability to communicate preference decision.
6. pETR Resolution
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 [RFC9301]. This Map-Reply has the following
content (as defined per regular map-reply and negative-map-reply in
[RFC9301]):
- An EID-Prefix calculated as non-LISP "hole" per the procedures in
[RFC9301] 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
[RFC9306] about the mapping such as whether the mapping is based upon
policy or registration.
7. pETR Map-Cache Update
On receiving pETR Map-Notify/Map-Reply from the mapping system, ITR
MAY install/update map-cache and encapsulate the packets to pETR
RLOCs as per [RFC 9300] for the destinations not known to the mapping
system as EIDs or known EIDs not registered to the mapping system.
This can be implemented as follows,
- ITR SHOULD configure the known EID-blocks in its map-cache to
always generate Map-Request for known EIDs. These would be more
specific map-cache entries than “hole” EID-Prefix or default map-
cache entries.
- On receiving pETR Map-Notify/Map-Reply, ITR MAY install/update
following map-cache entries with pETR RLOCs,
- “hole” prefix [RFC9301] map-cache entry to encapsulate the packets
to pETR RLOCs
- default map-cache entry to encapsulate the packets to pETR RLOCs.
8. IANA Considerations
No IANA considerations apply to this document.
9. Security Considerations
There are no additional security considerations except what already
discussed in [RFC9301].
10. Acknowledgements
The authors would like to thank Fabio Maino, Dino Farinacci and Padma
Pillay-Esnault for the suggestions and review of this document.
11. Normative Reference
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[I-D.ietf-lisp-name-encoding]
Farinacci, D., "LISP Distinguished Name Encoding", Work in
Progress, Internet-Draft, draft-ietf-lisp-name-encoding-
02, 20 August 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-lisp-
name-encoding-02>.
[I-D.ietf-lisp-vpn]
Moreno, V. and D. Farinacci, "LISP Virtual Private
Networks (VPNs)", Work in Progress, Internet-Draft, draft-
ietf-lisp-vpn-12, 19 September 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-lisp-
vpn-12>.
[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>.
[RFC9300] Farinacci, D., Fuller, V., Meyer, D., Lewis, D., and A.
Cabellos, Ed., "The Locator/ID Separation Protocol
(LISP)", RFC 9300, DOI 10.17487/RFC9300, October 2022,
<https://www.rfc-editor.org/info/rfc9300>.
[RFC9301] Farinacci, D., Maino, F., Fuller, V., and A. Cabellos,
Ed., "Locator/ID Separation Protocol (LISP) Control
Plane", RFC 9301, DOI 10.17487/RFC9301, October 2022,
<https://www.rfc-editor.org/info/rfc9301>.
[RFC9306] Rodriguez-Natal, A., Ermagan, V., Smirnov, A., Ashtaputre,
V., and D. Farinacci, "Vendor-Specific LISP Canonical
Address Format (LCAF)", RFC 9306, DOI 10.17487/RFC9306,
October 2022, <https://www.rfc-editor.org/info/rfc9306>.
[RFC9437] Rodriguez-Natal, A., Ermagan, V., Cabellos, A., Barkai,
S., and M. Boucadair, "Publish/Subscribe Functionality for
the Locator/ID Separation Protocol (LISP)", RFC 9437,
DOI 10.17487/RFC9437, August 2023,
<https://www.rfc-editor.org/info/rfc9437>.
Authors' Addresses
Prakash Jain
Cisco Systems
San Jose, CA
United States of America
Email: prakjain@cisco.com
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Victor Moreno
Google
Mountainview, CA
United States of America
Email: vimoreno@google.com
Sanjay Hooda
Cisco Systems
San Jose, CA
United States of America
Email: shooda@cisco.com
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