RFC 10040
Locator/ID Separation Protocol (LISP) Geo-Coordinates
Locator/ID Separation Protocol (LISP) Geo-Coordinates ✨
Okay bestie, this is RFC 10040 🎀 It was written by D. Farinacci from lispers.net, it's dated September 2026, and it's an Experimental doc (ISSN 2070-1721). It's an IETF document, and it updates RFC 8060. The header doesn't list anything it obsoletes, so nothing gets replaced here.
Abstract 💖
This document explains how Geo-Coordinates can be used in the Locator/ID Separation Protocol (LISP) and defines a new LISP Canonical Address Format (LCAF) encoding for them. It's giving "geo-coords, but make it a proper LISP type" 🌍
This document updates RFC 8060.
Status of This Memo 🦋
Not a Standards Track spec, bestie. It's published for examination, experimental implementation, and evaluation.
This is an Experimental Protocol for the Internet community. It's a product of the Internet Engineering Task Force (IETF) and represents the consensus of the IETF community. It went through public review and got approved for publication by the Internet Engineering Steering Group (IESG). Not every IESG-approved document is a candidate for any level of Internet Standard, so see Section 2 of RFC 7841 for that 🙈
Info about the current status of this document, any errata, and how to send feedback is at https://www.rfc-editor.org/info/rfc10040.
Copyright Notice 🎀
Copyright (c) 2026 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 Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) as they stand on the publication date. Read those carefully, because they spell out your rights and restrictions for this document. Code Components pulled out of this document must include Revised BSD License text, as described in Section 4.e of the Trust Legal Provisions, and they come without warranty, as described in the Revised BSD License.
Table of Contents 📑
1. Introduction
2. Requirements Language
3. Definition of Terms
4. Geo-Points in RLOC-Records
5. Geo-Prefixes in EID-Records and RLOC-Records
6. Geo-Points and Geo-Prefixes Examples
6.1. Locating a Package
6.2. Wireless Connectivity
6.3. Vehicular Networks
7. Geo-Prefix and Geo-Point Encodings
8. Backward-Compatibility Considerations
9. Security Considerations
10. Privacy Considerations
11. IANA Considerations
12. References
12.1. Normative References
12.2. Informative References
Acknowledgments
Author's Address1. Introduction ✨
So the Locator/ID Separation Protocol (LISP) [RFC9300] brings in two new namespaces, Endpoint Identifiers (EIDs) and Routing Locators (RLOCs). They're meant to pull identity and topological location apart from an IP address, which is honestly iconic 👑 To keep things flexible for current and future applications, these values can be encoded in LISP control messages using a general syntax that includes Address Family Identifiers (AFIs) [AFN].
This document defines a new LCAF encoding for Geo-Coordinates. It's different from the structure in [RFC9179] because the team wanted a more compact encoding 💅
This document updates [RFC8060]. The big change is that the Geo-Coordinates encoding in Section 4.3 of [RFC8060], which is identified by LCAF type 5, is now deprecated 😭 The new LCAF type in this document is called "Geo-Location", and it's got a brand-new LCAF type number allocated to it.
The Geo-Location LCAF type gets used in EID-Records and RLOC-Records. For which LISP messages contain those records, check [RFC9301] ✨
This document is part of a bigger effort to bring Geo-Coordinates into LISP. It is not part of an "experiment", since not every Experimental RFC is necessarily part of one. It's really about the maturity level of the technology 🧚
2. Requirements Language 🫶
Here's the key-word part, and it matters. 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. Lowercase versions don't count, so don't get it twisted 💀
3. Definition of Terms 🌸
For the basic terms "EID", "RLOC", and "xTR", go to [RFC9300] for the authoritative definitions. The terms in this section add to those canonical definitions so they fit the design in this spec 🍓
- Geo-Point: A coordinate according to [GEO] that defines a point using the latitude, longitude, and altitude parameters.
- Geo-Prefix: Forms a sphere (in three dimensions) of a geographic area, made up of a Geo-Point and a radius. A Geo-Point is known to be "more specific" than a Geo-Prefix when its physical location is within the geographic sphere 🌈
4. Geo-Points in RLOC-Records 🦋
Geo-Points MAY be present in an RLOC-Record to figure out the physical location of an Egress Tunnel Router (ETR) or Re-encapsulating Tunneling Router (RTR). This can help when topological distance is inaccurate or hidden, because it lets you work out geographical distance instead 🗺️ When Geo-Points are encoded in RLOC-Records with RLOC addresses, the LCAF AFI-List Type SHOULD be used.
Geo-Points MAY also be the only thing in an RLOC-Record when an EID maps to a Geo-Coordinate. If you want to find the geographical location of any EID, this method is super convenient ✨ Picture this: an EID belongs to a physical shipping package from a delivery company, and the EID is an IPv6 address with the tracking number embedded in it. The network has LISP nodes deployed in lots of locations, each configured with its own Geo-Coordinates. As the package roams, whichever LISP node spots the EID registers it with the LISP Mapping Database System. So the EID-to-RLOC mapping is EID=IPv6 and RLOC=geo-point. If someone does a Mapping Database System lookup on that IPv6 EID, the Geo-Coordinate comes back. As the EID keeps roaming, new registrations with different Geo-Coordinates get stored, which means you can physically track the package 📦🔥
Part 2 picks up at Section 5 💖
7. Geo-Prefix and Geo-Point Encodings ✨
okay so when a Geo-Prefix or a Geo-Point gets encoded in an EID-Record, it's encoded solely with the Geo-Location LCAF Type format 💖 as long as VPNs are not in use. when VPNs are in use, the Geo-Location LCAF Type gets tucked into the AFI field of the Instance-ID LCAF Type 🎀
this doc has no way to validate the Geo-Location values 🙈
here's the layout of the Geo-Location format, and I'm obsessed 😭
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFI = 16387 | Rsvd1 | Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 17 | Rsvd2 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|N|E|A|M|R|K| Reserved | Location Uncertainty |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Lat Degrees | Latitude Milliseconds |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Long Degrees | Longitude Milliseconds |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Altitude |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Radius | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFI | Address ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: Geo-Location LCAF Encoding Format- AFI: set to
16387to say the address is using the LCAF format from [RFC8060] 🫶 - Type:
17🌸 - Rsvd1/Rsvd2/Flags: see [RFC8060] for the deets 🧚
- Length: the length in bytes, starting with and including the byte after the
Lengthfield 🍓 - U-bit: if the U-bit is set, the
Location Uncertaintyfield is used. if it's clear,Location Uncertaintygets sent as 0 and is ignored on receipt 🦋 - N-bit: if the N-bit is set, the latitude is north of the Equator. if it's clear, the latitude is south of the Equator 🌍
- E-bit: if the E-bit is set, the longitude is east of the Prime Meridian. if it's clear, the longitude is west of the Prime Meridian 🧭
- A-bit: if the A-bit is set, the
Altitudefield is used. if it's clear,Altitudeis sent as 0 and ignored on receipt ⛰️ - M-bit: if the M-bit is set, the altitude is in meters. if it's clear, the altitude is in centimeters 📏
- R-bit: if the R-bit is set, the
Radiusfield is used and the encoding is a Geo-Prefix. if it's clear,Radiusis set to 0 and the encoding is a Geo-Point 🎯 - K-bit: if the K-bit is set, the radius is in kilometers. if it's clear, the radius is in meters 🗺️
- Reserved: reserved for future addition of bit fields. these bits MUST be set to 0 when sending protocol packets and MUST be ignored when receiving protocol packets 🔒
- Location Uncertainty: an unsigned 16-bit integer for the number of centimeters of uncertainty for the location 🫧
- Latitude Degrees: an unsigned 8-bit integer ranging from 0 to 90 degrees north or south of the Equator (northern or southern hemisphere, respectively) 🌏
- Latitude Milliseconds: an unsigned 24-bit integer ranging from 0 to 3,599,999 (i.e., less than 60 minutes) ⏱️
- Longitude Degrees: an unsigned 8-bit integer ranging from 0 to 180 degrees east or west of the Prime Meridian 🌐
- Longitude Milliseconds: an unsigned 24-bit integer ranging from 0 to 3,599,999 (i.e., less than 60 minutes) ⏲️
- Altitude: a signed 32-bit integer containing the height relative to sea level, in centimeters or meters. a negative height means the location is below sea level 🌊
- Radius: an unsigned 16-bit integer containing the radius of a sphere (or circle if altitude isn't specified) centered on the specified coordinates. the radius is in meters unless the K-bit is set, which means kilometers. when the radius is specified, this LCAF type encodes a Geo-Prefix, where the Geo-Coordinates define the entire area of the sphere or circle defined by the radius and center point 🔵
- AFI/Address: the
AFIfield indicates the Address Family Identifier [AFN] [RFC8060] for the address in theAddressfield 💜
8. Backward-Compatibility Considerations 🔁
okay so EID-Records encoded with the Geo-Location LCAF are only supported by LISP nodes that support them for registration and lookup purposes 🎀
RLOC-Records encoded with the Geo-Location LCAF can get returned from Mapping Database System lookups to LISP nodes that don't understand them. in that case, the RLOC-Record is ignored 🙃
9. Security Considerations 🔐
this section is SERIOUS, bestie 😭 the use of Geo-Coordinates in any application must be considered carefully so it doesn't violate any privacy concerns about physical location. this document does take into consideration the applicability of BCP 160 [RFC6280] for location-based privacy protection 🛡️
in a LISP environment, Geo-Coordinates can be registered to the Mapping Database System. when that happens, any Tunnel Router (xTR) is letting its physical location be known to queriers of the Mapping Database System, as well as to the network components that make up the Mapping Database System 👀 there are various sets of trust relationships that may exist 🤝
when xTRs register their mappings with Geo-Coordinate information, a policy is attached about who can access that info. the policy is typically stored locally on the xTR and applied when the Mapping Service Provider (MSP) forwards Map-Requests to the xTRs of the LISP site. depending on the requesting xTR, the responding xTR can apply the local policy to decide whether a Map-Reply goes out with all RLOC-Records or, maybe, only the RLOC-Records that don't contain Geo-Coordinate information 🫣
the MSP can also be asked by LISP site xTRs to proxy Map-Replies to Map-Requests. in this case, the MSP MUST apply the xTR policy so only authorized requesters get access to Geo-Coordinate information 🚨
note that once a requester is authorized, Map-Replies are returned directly to the requester and are signed as described in [RFC9303]. the Map-Replies not only authenticate the Map-Replier but can also be encrypted by the Map-Replier, so no eavesdropping of Geo-Coordinate information can occur 🔏
in most deployments, there's no tracking of EID host-based systems, since Geo-Coordinate assignment is typically registered for LISP xTR devices or other asset inventory. BUT, since Geo-Coordinate-encoded RLOCs can be associated with any EID, tracking of hosts can occur if such an EID is assigned to hosts 💀
10. Privacy Considerations 🫶
so on top of controlling where LISP Geo-Coordinate mapping records go and applying policies (see "Security Considerations" section) for who can access them, there are extra steps you can take to protect against threats 🧸
the privacy guidelines in [RFC6973] can be implemented with existing LISP features, for example:
- using signatures from [ECDSA-AUTH] can authenticate and authorize who can request such mapping records 🔑
- obfuscating a Geo-Point by using Geo-Prefixes uses data minimization techniques 🫧
- using short TTLs so the Geo-Coordinate mapping records are ephemeral reduces the attack window ⏳
the typical applicability for Geo-Coordinates is describing the physical location of well-known public structures, places, and landmarks, rather than people, vehicles, and equipment 🏛️🗼
11. IANA Considerations 📋
following the guidelines of [RFC8126], IANA has assigned the following value in the "LISP Canonical Address Format (LCAF) Types" registry [RFC8060]:
+=======+=====================+======================+
| Value | LISP LCAF Type Name | Reference |
+=======+=====================+======================+
| 17 | Geo-Location | RFC 10040, Section 7 |
+-------+---------------------+----------------------+
Table 1: Geo-Location LCAF Type Assignmentin addition, IANA has marked LCAF type 5 (Geo-Coordinates) as deprecated in the "LISP Canonical Address Format (LCAF) Types" registry. this type was defined in [RFC8060], which this document updates 🌈
12. References ✨
12.1. Normative References 📚
okay bestie, these are the sources the spec actually leans on, so they're must-reads 💅 Here they are, verbatim:
[GEO] National Geospatial-Intelligence Agency, "Department of
Defense World Geodetic System 1984: Its Definition and
Relationships with Local Geodetic Systems",
NGA.STND.0036_1.0.0_WGS84, 8 July 2014,
<https://nsgreg.nga.mil/doc/view?i=4085>.
[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>.
[RFC6280] Barnes, R., Lepinski, M., Cooper, A., Morris, J.,
Tschofenig, H., and H. Schulzrinne, "An Architecture for
Location and Location Privacy in Internet Applications",
BCP 160, RFC 6280, DOI 10.17487/RFC6280, July 2011,
<https://www.rfc-editor.org/info/rfc6280>.
[RFC6973] Cooper, A., Tschofenig, H., Aboba, B., Peterson, J.,
Morris, J., Hansen, M., and R. Smith, "Privacy
Considerations for Internet Protocols", RFC 6973,
DOI 10.17487/RFC6973, July 2013,
<https://www.rfc-editor.org/info/rfc6973>.
[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>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC9179] Hopps, C., "A YANG Grouping for Geographic Locations",
RFC 9179, DOI 10.17487/RFC9179, February 2022,
<https://www.rfc-editor.org/info/rfc9179>.
[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>.
[RFC9303] Maino, F., Ermagan, V., Cabellos, A., and D. Saucez,
"Locator/ID Separation Protocol Security (LISP-SEC)",
RFC 9303, DOI 10.17487/RFC9303, October 2022,
<https://www.rfc-editor.org/info/rfc9303>.
[RFC9735] Farinacci, D. and L. Iannone, Ed., "Locator/ID Separation
Protocol (LISP) Distinguished Name Encoding", RFC 9735,
DOI 10.17487/RFC9735, February 2025,
<https://www.rfc-editor.org/info/rfc9735>.12.2. Informative References 🔍
these ones are the helpful extras, the nice-to-know reading that gives you the bigger picture 🌸
[AFN] IANA, "Address Family Numbers",
<http://www.iana.org/assignments/address-family-numbers>.
[BGP-GEO] Chen, E., Shen, N., and R. Raszuk, "Carrying Geo
Coordinates in BGP", Work in Progress, Internet-Draft,
draft-chen-idr-geo-coordinates-02, 31 October 2016,
<https://datatracker.ietf.org/doc/html/draft-chen-idr-geo-
coordinates-02>.
[ECDSA-AUTH]
Farinacci, D. and E. Nordmark, "LISP Control-Plane ECDSA
Authentication and Authorization", Work in Progress,
Internet-Draft, draft-ietf-lisp-ecdsa-auth-17, 26 July
2026, <https://datatracker.ietf.org/doc/html/draft-ietf-
lisp-ecdsa-auth-17>.
[ISIS-GEO] Shen, N., Ed. and E. Chen, "Carrying Geo Coordinates
Information In IS-IS", Work in Progress, Internet-Draft,
draft-shen-isis-geo-coordinates-04, 18 October 2017,
<https://datatracker.ietf.org/doc/html/draft-shen-isis-
geo-coordinates-04>.
[OSPF-GEO] Lindem, A., Ed., Shen, N., and E. Chen, "OSPF Extensions
for Advertising/Signaling Geo Location Information", Work
in Progress, Internet-Draft, draft-acee-ospf-geo-location-
05, 18 October 2017,
<https://datatracker.ietf.org/doc/html/draft-acee-ospf-
geo-location-05>.
[PRED-RLOCS]
Farinacci, D. and P. Pillay-Esnault, "LISP Predictive
RLOCs", Work in Progress, Internet-Draft, draft-ietf-lisp-
predictive-rlocs-15, 19 September 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-lisp-
predictive-rlocs-15>.
[V2I-PROB] Jeong, J. P. and T. T. Oh, "Problem Statement for Vehicle-
to-Infrastructure Networking", Work in Progress, Internet-
Draft, draft-jeong-its-v2i-problem-statement-02, 19 July
2016, <https://datatracker.ietf.org/doc/html/draft-jeong-
its-v2i-problem-statement-02>.Acknowledgments 🙌
big thank-you to the LISP WG for reviewing and accepting this document, and to Kiran Makhijani for shepherding it along ✨
special shoutout to Chris Hopps, Enke Chen, Acee Lindem, and Naiming Shen for collaborating on a Geo-Location encoding format that's consistent with OSPF [OSPF-GEO], IS-IS [ISIS-GEO], and BGP [BGP-GEO]. teamwork makes the dream work 🫶💜
Author's Address 📮
Dino Farinacci
lispers.net
San Jose, CA
United States of America
Email: farinacci@gmail.com📦 where this page comes from
- ietf: rfc10040 2026-09
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