Skip to main content

LISP Canonical Address Format (LCAF)
draft-ietf-lisp-rfc8060bis-04

Document Type Active Internet-Draft (lisp WG)
Authors Alvaro Retana , Dino Farinacci , Job Snijders , Alberto Rodriguez-Natal
Last updated 2026-02-17
Replaces draft-retana-lisp-rfc8060bis
RFC stream Internet Engineering Task Force (IETF)
Intended RFC status (None)
Formats
Additional resources Mailing list discussion
Stream WG state WG Document
Document shepherd (None)
IESG IESG state I-D Exists
Consensus boilerplate Unknown
Telechat date (None)
Responsible AD (None)
Send notices to (None)
draft-ietf-lisp-rfc8060bis-04
Internet Engineering Task Force                           A. Retana, Ed.
Internet-Draft                              Futurewei Technologies, Inc.
Obsoletes: 8060, 9306 (if approved)                         D. Farinacci
Intended status: Standards Track                             lispers.net
Expires: 21 August 2026                                      J. Snijders
                                                                        
                                                      A. Rodriguez-Natal
                                                                   Cisco
                                                        17 February 2026

                  LISP Canonical Address Format (LCAF)
                     draft-ietf-lisp-rfc8060bis-04

Abstract

   This document defines a canonical address format encoding used in
   Locator/ID Separation Protocol (LISP) control messages and in the
   encoding of lookup keys for the LISP Mapping Database System.

   This document obsoletes RFC 8060 and RFC 9306.

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 21 August 2026.

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) in effect on the date of publication of this document.
   Please review these documents carefully, as they describe your rights

Retana, et al.           Expires 21 August 2026                 [Page 1]
Internet-Draft        LISP Canonical Address Format        February 2026

   and restrictions with respect to this document.  Code Components
   extracted from this document must include Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   4
     2.1.  Requirements Language . . . . . . . . . . . . . . . . . .   4
     2.2.  Definition of Terms . . . . . . . . . . . . . . . . . . .   4
   3.  LISP Canonical Address Format Encoding  . . . . . . . . . . .   4
   4.  LISP Canonical Address Types  . . . . . . . . . . . . . . . .   5
     4.1.  The AFI List LCAF Type  . . . . . . . . . . . . . . . . .   6
       4.1.1.  Binding IPv4 and IPv6 Addresses . . . . . . . . . . .   6
       4.1.2.  Layer 2 VPNs  . . . . . . . . . . . . . . . . . . . .   7
       4.1.3.  ASCII Names in the Mapping Database . . . . . . . . .   8
       4.1.4.  Using Recursive LISP Canonical Address Encodings  . .   8
       4.1.5.  Compatibility Mode Use Case . . . . . . . . . . . . .   9
     4.2.  The Instance ID LCAF Type . . . . . . . . . . . . . . . .  10
     4.3.  The AS Number LCAF Type . . . . . . . . . . . . . . . . .  11
     4.4.  The Application Data LCAF Type  . . . . . . . . . . . . .  12
     4.5.  The Opaque Key LCAF Type  . . . . . . . . . . . . . . . .  13
     4.6.  The NAT-Traversal LCAF Type . . . . . . . . . . . . . . .  14
     4.7.  The Nonce Locator LCAF Type . . . . . . . . . . . . . . .  16
     4.8.  The Multicast Info LCAF Type  . . . . . . . . . . . . . .  17
     4.9.  The Explicit Locator Path LCAF Type . . . . . . . . . . .  18
     4.10. The Security Key LCAF Type  . . . . . . . . . . . . . . .  19
     4.11. The Source/Destination LCAF Type  . . . . . . . . . . . .  20
     4.12. The Replication List LCAF Type  . . . . . . . . . . . . .  21
     4.13. The JSON Data Model LCAF Type . . . . . . . . . . . . . .  22
     4.14. The Key/Value Address Pair LCAF Type  . . . . . . . . . .  23
     4.15. The Encapsulation Format LCAF Type  . . . . . . . . . . .  23
     4.16. The Vendor-Specific LCAF Type . . . . . . . . . . . . . .  25
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  26
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  26
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  27
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .  28
     7.2.  Informative References  . . . . . . . . . . . . . . . . .  29
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .  32
   Contributors  . . . . . . . . . . . . . . . . . . . . . . . . . .  32
   Appendix A: Change Log  . . . . . . . . . . . . . . . . . . . . .  33
     Version -00 . . . . . . . . . . . . . . . . . . . . . . . . . .  33
     Version -01 . . . . . . . . . . . . . . . . . . . . . . . . . .  33
     Version -02 . . . . . . . . . . . . . . . . . . . . . . . . . .  33
     Version -03 . . . . . . . . . . . . . . . . . . . . . . . . . .  34
     Version -04 . . . . . . . . . . . . . . . . . . . . . . . . . .  34
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  34

Retana, et al.           Expires 21 August 2026                 [Page 2]
Internet-Draft        LISP Canonical Address Format        February 2026

1.  Introduction

   The LISP architecture and protocol [RFC9300] [RFC9301] introduces two
   namespaces: Endpoint Identifiers (EIDs) and Routing Locators (RLOCs).
   To provide flexibility for current and future applications, these
   values can be encoded in LISP control messages using a general syntax
   that includes Address Family Identifier (AFI), length, and value
   fields.

   The defined AFIs include IPv4 and IPv6 addresses, which are formatted
   as follows:

    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 = 1            |       IPv4 Address ...        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |     ...  IPv4 Address         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                       Figure 1: IPv4-Encoded Address

    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 = 2            |       IPv6 Address ...        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     ...  IPv6 Address  ...                    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     ...  IPv6 Address  ...                    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     ...  IPv6 Address  ...                    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |     ...  IPv6 Address         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                       Figure 2: IPv6-Encoded Address

   This document describes the AFIs used by LISP along with their
   encodings and introduces the LISP Canonical Address Format (LCAF)
   that can be used to define the LISP-specific encodings for arbitrary
   AFI values.

   Specific detailed uses for the LCAF Types defined in this document
   may be found in separate use-case documents.  The same LCAF Type may
   be used by more than one use-case.

   This document obsoletes [RFC8060] and [RFC9306].

Retana, et al.           Expires 21 August 2026                 [Page 3]
Internet-Draft        LISP Canonical Address Format        February 2026

2.  Terminology

2.1.  Requirements Language

   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.

2.2.  Definition of Terms

   Readers are expected to be familiar with the terminology defined in
   [RFC9300].

3.  LISP Canonical Address Format Encoding

   IANA has assigned AFI value 16387 (0x4003) to the LISP Canonical
   Address Format (LCAF).  This specification defines the encoding
   format of the LISP Canonical Address (LCA).

   The AFI definitions in [AFN] only allocate code-points for the AFI
   value itself.  The length of the address or entity that follows is
   not defined and is implied based on conventional experience.  LISP
   uses the following AFIs:

    +===========+=================+===================================+
    | AFI Value | Name            | Address Length (octets)           |
    +===========+=================+===================================+
    | 0         | Unspecified     | Null (see Section 3 of [RFC9300]) |
    |           | Encoded Address |                                   |
    +-----------+-----------------+-----------------------------------+
    | 1         | IPv4            | 4                                 |
    +-----------+-----------------+-----------------------------------+
    | 2         | IPv6            | 16                                |
    +-----------+-----------------+-----------------------------------+
    | 6         | 802 MAC Address | 6                                 |
    +-----------+-----------------+-----------------------------------+
    | 17        | Distinguished   | Variable: can be derived from the |
    |           | Name            | Length field. (see Section 4.1.3) |
    +-----------+-----------------+-----------------------------------+
    | 16387     | LCAF            | Variable. (see Section 4)         |
    +-----------+-----------------+-----------------------------------+

                       Table 1: LISP Address Families

   The first 6 octets of a LISP Canonical Address Format are followed by
   a variable number of fields of variable length (Payload):

Retana, et al.           Expires 21 August 2026                 [Page 4]
Internet-Draft        LISP Canonical Address Format        February 2026

    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       |     Rsvd2     |            Length             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     . . . (Payload) . . .                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

               Figure 3: LISP Canonical Address Format Header

   Rsvd1:  this field is reserved for future use and MUST be transmitted
      as 0 and ignored on receipt.

   Flags:  this 8-bit field is for future definition and use.  It MUST
      be set to zero on transmission and ignored on receipt.

   Type:  indicates the Type of the LISP Canonical Address Format
      encodings.  The values are summarized in Table 2 (Section 6).
      Unrecognized Types MUST be silently ignored.

      If all Locators are ignored, this is equivalent to a LISP control
      message with Locator Count = 0, as described in [RFC9301].  If an
      EID-Prefix only contains unrecognized LCAF types, the LISP control
      message MUST be dropped and the event MUST be logged.

   Rsvd2:  this field is reserved for future use and MUST be transmitted
      as 0 and ignored on receipt.  This field is Type-specific.

   Length:  this 16-bit field indicates the length in octets of the LISP
      Canonical Address Payload.

   [RFC9301] states RLOC-records based on an IP address are sorted when
   encoded in control messages, so the locator-set has consistent order
   across all xTRs for a given EID.  The sort order is based on sort-key
   {AFI, RLOC-address}. When an RLOC based on an IP address is LCAF
   encoded, the sort-key is {AFI, LCAF-Type, RLOC-address}. Therefore,
   when a locator-set has a mix of AFI records and LCAF records, they
   are ordered from smallest to largest AFI value.

4.  LISP Canonical Address Types

   The following sections specify the format of the currently defined
   set of Type values.

Retana, et al.           Expires 21 August 2026                 [Page 5]
Internet-Draft        LISP Canonical Address Format        February 2026

   Type 0 is used to indicate a "Null Body", which requires the Length
   value to be set to 0.  If the Length value is not 0, the Type 0 MUST
   be silently ignored.

4.1.  The AFI List LCAF Type

   The AFI List LCAF Type (Type 1) is used to carry a variable number of
   addresses in a single LCAF instance.  The Payload of this LCAF Type
   is a sequence of one or more AFI-encoded addresses.  The AFI List
   LCAF Type can be used in a variety of applications, some of which are
   described in the following subsections.

    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 = 1    |     Rsvd2     |            Length             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |              AFI              |          Address ...          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |      ...    Address           |              AFI              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                            Address ...                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

              Figure 4: AFI List LISP Canonical Address Format

   AFI:  an AFI value from Table 1.

   Address:  this field contains an address value in accordance to the
      AFI preceding it.  It's length is variable and is determined by
      the AFI.  See Table 1 for details.

   The AFI List LCAF can contain one or more AFI/Address pairs.

4.1.1.  Binding IPv4 and IPv6 Addresses

   When header translation between IPv4 and IPv6 is desirable, a LISP
   Canonical Address can use the AFI List LCAF Type to carry a variable
   number of AFIs in one LCAF AFI.

Retana, et al.           Expires 21 August 2026                 [Page 6]
Internet-Draft        LISP Canonical Address Format        February 2026

    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 = 1    |     Rsvd2     |            Length             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            AFI = 1            |       IPv4 Address ...        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |     ...  IPv4 Address         |            AFI = 2            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                          IPv6 Address ...                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     ...  IPv6 Address  ...                    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     ...  IPv6 Address  ...                    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     ...  IPv6 Address                         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

          Figure 5: Address Binding LISP Canonical Address Format

   This type of address format can be included in a Map-Request when,
   for example, the IPv6 address is being used as an EID, but the LISP
   Mapping Database System lookup destination can use only the IPv4
   address.  This is so a Mapping Database Service Transport System,
   such as LISP-ALT [RFC6836], can use the Map-Request destination
   address to route the control message to the desired LISP site.

   This encoding can be used in EID-records or RLOC-records in Map-
   Request, Map-Reply, Map-Register, and Map-Notify messages.

4.1.2.  Layer 2 VPNs

   When Media Access Control (MAC) addresses are stored in the LISP
   Mapping Database System, the AFI List LCAF Type can be used to carry
   AFI 6.

Retana, et al.           Expires 21 August 2026                 [Page 7]
Internet-Draft        LISP Canonical Address Format        February 2026

    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 = 1    |     Rsvd2     |             Length            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |             AFI = 6           |    Layer 2 MAC Address  ...   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                    ... Layer 2 MAC Address                    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

            Figure 6: MAC Address LISP Canonical Address Format

   This address format can be used to connect Layer 2 domains together
   using LISP over an IPv4 or IPv6 core network to create a Layer 2 VPN.
   In this use case, a MAC address is being used as an EID, and the
   locator-set that this EID maps to can be an IPv4 or IPv6 RLOC, or
   even another MAC address being used as an RLOC.  See
   [I-D.ietf-lisp-eid-mobility] for an example.

4.1.3.  ASCII Names in the Mapping Database

   If DNS names [RFC1035] or URIs [RFC3986] are stored in the LISP
   Mapping Database System, the AFI List LCAF Type can be used to carry
   an ASCII string.

    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 = 1    |     Rsvd2     |            Length             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |             AFI = 17          |      DNS Name or URI  ...     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

             Figure 7: ASCII Name LISP Canonical Address Format

   An example for using DNS names is when an ETR registers a mapping
   with an EID-record encoded as (AFI=1, 192.0.2.0/24) with an RLOC-
   record (AFI=17, "router.example.com").

4.1.4.  Using Recursive LISP Canonical Address Encodings

   When any combination of the above is desirable, the AFI List LCAF
   Type value can be used to carry within the LCAF AFI another LCAF AFI
   (for example, Application-Specific Data in Section 4.4).

Retana, et al.           Expires 21 August 2026                 [Page 8]
Internet-Draft        LISP Canonical Address Format        February 2026

    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 = 1    |     Rsvd2     |            Length             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |           AFI = 16387         |     Rsvd1     |     Flags     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Type = 4    |     Rsvd2     |            Length             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   IP TOS, IPv6 TC or Flow Label               |    Protocol   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Local Port (lower-range)   |    Local Port (upper-range)   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Remote Port (lower-range)   |   Remote Port (upper-range)   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            AFI = 1            |       IPv4 Address ...        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |     ...  IPv4 Address         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

             Figure 8: Recursive LISP Canonical Address Format

   This format could be used by a Mapping Database Service Transport
   System, such as LISP-ALT [RFC6836], where the AFI=1 IPv4 address is
   used as an EID and placed in the Map-Request destination address by
   the sending LISP system.  The LISP-ALT system can deliver the Map-
   Request to the LISP destination site independent of the Application
   Data LCAF Type AFI payload values (Section 4.4).  When this AFI is
   processed by the destination LISP site, it can return different
   locator sets based on the type of application or level of service
   that is being requested.

4.1.5.  Compatibility Mode Use Case

   A LISP system should use the AFI List LCAF Type format when sending
   to LISP systems that do not support a particular LCAF Type used to
   encode locators.  This allows the receiving system to be able to
   parse a locator address for encapsulation purposes.  The list of AFIs
   in an AFI List LCAF Type has no semantic ordering and a receiver
   should parse each AFI element no matter what the ordering.

Retana, et al.           Expires 21 August 2026                 [Page 9]
Internet-Draft        LISP Canonical Address Format        February 2026

    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 = 1    |     Rsvd2     |            Length             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |           AFI = 16387         |     Rsvd1     |     Flags     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Type = 3    |     Rsvd2     |            Length             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                           AS Number                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |              AFI = 0          |           AFI = 1             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                          IPv4 Address                         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

         Figure 9: Compatibility Mode LISP Canonical Address Format

   For example, if a system does not recognize the AS Number LCAF Type
   (Section 4.3) that accompanies a locator address, an encoder can
   include the AS Number LCAF Type embedded in an AFI List LCAF Type
   where the AFI in the AS Number LCAF Type is set to 0 and the AFI
   encoded next in the list is encoded with a valid AFI value to
   identify the locator address.

   A LISP system is required to support the AFI List LCAF Type to use
   this procedure.  It would skip over 10 octets of the AS Number LCAF
   Type to get to the locator address encoding (an IPv4 locator
   address).  A LISP system that does support the AS Number LCAF Type
   can support parsing the locator address in the encoding that follows
   in the AFI List LCAF Type.

4.2.  The Instance ID LCAF Type

   The Instance ID LCAF Type (Type 2) is used to carry an Instance ID
   along with an AFI-based address.  The Instance ID can be used when
   virtualization and segmentation are needed; see see Section 8 of
   [RFC9300] and [I-D.ietf-lisp-vpn] for more details.

Retana, et al.           Expires 21 August 2026                [Page 10]
Internet-Draft        LISP Canonical Address Format        February 2026

    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 = 2    | IID mask-len  |            Length             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                         Instance ID                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                AFI            |         Address  ...          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

            Figure 10: Instance ID LISP Canonical Address Format

   IID mask-len:  if the AFI is set to 0, then this LCAF is encoding an
      Instance ID range where this field indicates the number of high-
      order bits used in the Instance ID field for the range.  The low-
      order bits of the Instance ID field MUST be 0 and ignored.

      If the AFI is set to any other value, then this LCAF is encoding
      an extended EID prefix [I-D.ietf-lisp-8111bis].  In this case,
      this field is not used and MUST be set to 0 on transmission and
      ignored on receipt.

   Instance ID:  32-bit unstructured field.

   AFI:  as specified in Section 4.1.  Only AFI values for the
      Unspecified Encoded Address (0), IPv4 (1), and IPv6 (2) are valid
      in this LCAF Type.  Any other AFI value is invalid and the LCAF
      Type MUST be silently ignored.

   Address:  as specified in Section 4.1.

4.3.  The AS Number LCAF Type

   The AS Number LCAF Type (Type 3) is used to carry an Autonomous
   System (AS) number, which can be stored in the LISP Mapping Database
   System for either policy or documentation reasons.

Retana, et al.           Expires 21 August 2026                [Page 11]
Internet-Draft        LISP Canonical Address Format        February 2026

    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 = 3    |     Rsvd2     |             Length            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                           AS Number                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                AFI            |         Address  ...          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

             Figure 11: AS Number LISP Canonical Address Format

   AS Number:  the 32-bit AS number of the autonomous system that has
      been assigned to either the EID or RLOC that follows.  Two-octet
      AS numbers are encoded by setting the two high-order octets of the
      field to zero as specified in [RFC6793].

   AFI:  as specified in Section 4.1.  Only AFI values for IPv4 (1) and
      IPv6 (2) are valid in this LCAF Type.  Any other AFI value is
      invalid and the LCAF Type MUST be silently ignored.

   Address:  as specified in Section 4.1.

   The AS Number LCAF Type can be used to encode either EID or RLOC
   addresses.  The former is used to describe the LISP-ALT AS number the
   EID prefix for the site is being carried for.  The latter is used to
   describe the AS that is carrying RLOC based prefixes in the
   underlying routing system.

4.4.  The Application Data LCAF Type

   The Application Data LCAF Type (Type 4) is used to carry information
   about the type of application or Per-Hop Behavior (PHB) [RFC2475] of
   packets.

   For example, the Application Data LCAF Type is used for an EID
   encoding when an ITR wants a locator-set for a specific application.
   When used for an RLOC encoding, the ETR is supplying a locator-set
   for each specific application is has been configured to advertise.

Retana, et al.           Expires 21 August 2026                [Page 12]
Internet-Draft        LISP Canonical Address Format        February 2026

    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 = 4    |     Rsvd2     |            Length             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |       IP TOS, IPv6 TC, or Flow Label          |    Protocol   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Local Port (lower-range)   |    Local Port (upper-range)   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Remote Port (lower-range)   |   Remote Port (upper-range)   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                AFI            |         Address  ...          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

         Figure 12: Application Data LISP Canonical Address Format

   IP TOS, IPv6 TC, or Flow Label:  this field stores the 8-bit IPv4 TOS
      field used in an IPv4 header, the 8-bit IPv6 Traffic Class, or the
      20-bit Flow Label used in an IPv6 header.  The corresponding field
      is selected based on the AFI value used in the Address field.  The
      unused bits in this field MUST be set to 0 on transmission.  The
      value MUST be included in the low-order bits of the field.

   Protocol:  this field stores the protocol number for TCP (6), UDP
      (17), or Stream Control Transmission Protocol (SCTP) (132).  Any
      other value is invalid and the LCAF Type MUST be silently ignored.

   Local Port/Remote Port:  these fields are from the TCP [RFC9293], UDP
      [RFC768], or SCTP [RFC9260] transport header.  A range can be
      specified by using a lower-range and an upper-range.  When a
      single port is encoded, the lower-range and upper-range fields
      MUST be the same.  If the lower-range field is not equal to the
      upper-range field, then the lower-range field MUST be less than
      the upper-range field or the LCAF Type MUST be silently ignored.

   AFI:  as specified in Section 4.1.  Only AFI values for IPv4 (1) and
      IPv6 (2) are valid in this LCAF Type.  Any other AFI value is
      invalid and the LCAF Type MUST be silently ignored.

   Address:  as specified in Section 4.1.

4.5.  The Opaque Key LCAF Type

   The Opaque Key LCAF Type (Type 6) is used to carry a generic
   formatted key that can be used to do a LISP Mapping Database System
   lookup.

Retana, et al.           Expires 21 August 2026                [Page 13]
Internet-Draft        LISP Canonical Address Format        February 2026

    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 = 6    |     Rsvd2     |             Length            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Key Field Num |      Key Wildcard Fields      |   Key . . .   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       . . . Key                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

            Figure 13: Opaque Key LISP Canonical Address Format

   Key Field Num:  the value of this field is the number of "Key" sub-
      fields minus 1, the key can be broken up into.  For example, if
      this field has a value of 0, there is one "Key" sub-field.  The
      valid values range is 0 to 15.  If the value is greater than 15,
      the LCAF Type MUST be silently ignored.

   Key Wildcard Fields:  describes which fields in the key are not used
      as part of the key lookup.  This wildcard encoding is a bitfield.
      Each bit is a don't-care bit for a corresponding Key field.  Bit 0
      (the low-order bit) in this bitfield corresponds the first Key
      field, the low-order field in the key, bit 1 the second Key field,
      and so on.  When a bit is set in the bitfield, it is a don't-care
      bit and should not be considered as part of the database lookup.
      When the entire 16 bits are set to 0, then all bits of the key are
      used for the database lookup.  Any bits set to 1 that correspond
      to non-existent Key fields (for example, bit 5 set when there are
      only 3 Key fields) MUST be ignored.

   Key:  a series of Key sub-fields contain the variable length key.
      The length of each sub-field is determined by dividing the total
      length of the key (Length - 3) by the number of fields (Key Field
      Num + 1).  For example, for a key size of 8 octets (the Length
      field is set to 11), with a Key Field Num of 3, four sub-fields of
      2 octets each are present.  The number of Key fields MUST evenly
      divide (without remainder) into the total length of the key or the
      LCAF Type MUST be silently ignored.

4.6.  The NAT-Traversal LCAF Type

   The NAT-Traversal LCAF Type (Type 7) can be used to carry information
   about global and private addresses and port numbers when a LISP
   system is traversing a Network Address Translation (NAT) device.  See
   [I-D.ietf-lisp-nat-traversal] and
   [I-D.farinacci-lisp-lispers-net-nat] for examples of its use.

Retana, et al.           Expires 21 August 2026                [Page 14]
Internet-Draft        LISP Canonical Address Format        February 2026

    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 = 7    |     Rsvd2     |             Length            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |       MS UDP Port Number      |      ETR UDP Port Number      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                AFI            |  Global ETR RLOC Address  ... |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                AFI            |       MS RLOC Address  ...    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                AFI            | Private ETR RLOC Address  ... |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                AFI            |      RTR RLOC Address 1 ...   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                AFI            |      RTR RLOC Address k ...   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

           Figure 14: NAT-Traversal LISP Canonical Address Format

   MS UDP Port Number:  this is the UDP port number of the Map-Server
      and is set to 4342 [RFC9301].  Any other value is invalid and the
      LCAF Type MUST be silently ignored.

   ETR UDP Port Number:  this is the port number returned to a LISP
      system that was copied from the source port from a packet that has
      flowed through a NAT device.

   AFI:  as specified in Section 4.1.  Except for the last set of
      addresses (RTR RLOC Addresses, where AFI = 0 is also allowed),
      only AFI values for IPv4 (1) and IPv6 (2) are valid in this LCAF
      Type.  Any other AFI value is invalid and the LCAF Type MUST be
      silently ignored.  All the AFI fields (including the RTR RLOC
      Addresses, if not using AFI = 0) MUST be the same.  Otherwise, the
      LCAF Type MUST be silently ignored.

   Global ETR RLOC Address:  this is an address (as specified in
      Section 4.1) known to be globally unique built by NAT-traversal
      functionality in a LISP router.

   MS RLOC Address:  this is the address (as specified in Section 4.1)
      of the Map-Server used in the destination RLOC of a packet that
      has flowed through a NAT device.

   Private ETR RLOC Address:  this is an address (as specified in

Retana, et al.           Expires 21 August 2026                [Page 15]
Internet-Draft        LISP Canonical Address Format        February 2026

      Section 4.1) known to be a private address inserted in this LCAF
      by a LISP router that resides on the private side of a NAT device.

   RTR RLOC Address:  this is an encapsulation address (as specified in
      Section 4.1) used by an Ingress Tunnel Router (ITR) or Proxy
      Ingress Tunnel Router (PITR) that resides behind a NAT device.
      This address is known to have state in a NAT device so packets can
      flow from it to the LISP ETR behind the NAT.  There can be zero or
      more NAT Re-encapsulating Tunnel Router (RTR) [RFC9300] addresses
      supplied in this set of fields.  The number of RTRs encoded is
      determined by the Length field.  When there are no RTRs supplied,
      the RTR fields can be omitted and reflected in the LCAF Length
      field or an AFI of 0 can be used to indicate zero RTRs encoded.

4.7.  The Nonce Locator LCAF Type

   The Nonce Locator LCAF Type (Type 8) is used to carry a nonce value
   along with an AFI-based address.  This LCAF Type can be used, for
   example, by a public Proxy-ETR [RFC6832] device to verify who is
   encapsulating to it: it can check for a specific nonce value in the
   LISP-encapsulated packet.

    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 = 8    |     Rsvd2     |             Length            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Reserved    |                  Nonce                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                AFI            |         Address  ...          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

           Figure 15: Nonce Locator LISP Canonical Address Format

   Reserved:  this field is reserved for future use and MUST be
      transmitted as 0 and ignored on receipt.

   Nonce:  a 24-bit nonce value returned in a Map-Reply locator-record
      to be used by an ITR/Proxy-ITR when encapsulating to the locator
      address encoded in the AFI field of this LCAF Type.  This nonce
      value is inserted in the LISP Nonce field in the LISP header
      encapsulation [RFC9300].

   AFI:  as specified in Section 4.1.  Only AFI values for IPv4 (1) and
      IPv6 (2) are valid in this LCAF Type.  Any other AFI value is
      invalid and the LCAF Type MUST be silently ignored.

Retana, et al.           Expires 21 August 2026                [Page 16]
Internet-Draft        LISP Canonical Address Format        February 2026

   Address:  as specified in Section 4.1.

4.8.  The Multicast Info LCAF Type

   The Multicast Info LCAF Type (Type 9) is used to carry multicast
   group information.

   Multicast group information can be published in the mapping database
   using the Multicast Info LCAF Type.  This LCAF encoding can also be
   used to send broadcast packets to all members of a subnet when an EID
   is away from its home subnet location.

    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 = 9    |     Rsvd2     |             Length            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                         Instance ID                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Reserved           | Source MaskLen| Group MaskLen |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                AFI            |   Source/Subnet Address  ...  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                AFI            |       Group Address  ...      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

          Figure 16: Multicast Info LISP Canonical Address Format

   Instance ID:  as defined in Section 4.2.  The Instance ID in this
      LCAF can be used to associate a multicast forwarding entry for a
      given VPN.

   Reserved:  this field is reserved for future use and MUST be
      transmitted as 0 and ignored on receipt.

   Source MaskLen:  the mask length of the Source/Subnet Address that
      follows.  The length is the number of high-order mask bits set.

   Group MaskLen:  the mask length of the Group Address that follows.
      The length is the number of high-order mask bits set.

   AFI:  as specified in Section 4.1.  Only AFI values for IPv4 (1) and
      IPv6 (2) are valid in this LCAF Type.  Any other AFI value is
      invalid and the LCAF Type MUST be silently ignored.  All the AFI
      fields MUST be the same.  Otherwise, the LCAF Type MUST be
      silently ignored.

Retana, et al.           Expires 21 August 2026                [Page 17]
Internet-Draft        LISP Canonical Address Format        February 2026

   Source/Subnet Address:  the source address (as specified in
      Section 4.1) or prefix for encoding an (S,G) multicast entry
      [RFC4607].  A special wildcard value consisting of an address
      field of all zeros can be used to indicate any source.

   Group Address:  the group address or group prefix for encoding (S,G)
      or (*,G) multicast entries [RFC7761].  This field MUST be either a
      multicast address or a broadcast address.  Otherwise, the LCAF
      Type MUST be silently ignored.

4.9.  The Explicit Locator Path LCAF Type

   The Explicit Locator Path (ELP) LCAF Type (Type 10) is used to carry
   a list of locators in an explicit re-encapsulation path.  See
   [I-D.ietf-lisp-te] for an example.

    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 = 10   |     Rsvd2     |            Length             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |         Reserved        |L|P|S|             AFI               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                         Reencap Hop 1  ...                    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |         Reserved        |L|P|S|             AFI               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                         Reencap Hop k  ...                    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

       Figure 17: Explicit Locator Path LISP Canonical Address Format

   Reserved:  this field is reserved for future use and MUST be
      transmitted as 0 and ignored on receipt.

   L (Lookup bit):  this bit indicates that the address (in the Reencap
      Hop field) should not be used for encapsulation, but to look it up
      in the mapping database system to obtain an encapsulating RLOC
      address.

   P (RLOC Probe bit):  this bit indicates the Reencap Hop allows RLOC-
      probe messages [RFC9301] to be sent to it.  When the P bit is set
      to 0, RLOC-probes MUST NOT be sent.  If the Reencap Hop is an
      anycast address then the bit SHOULD be set to 0.

   S (Strict bit):  this bit, which indicates that the associated

Retana, et al.           Expires 21 August 2026                [Page 18]
Internet-Draft        LISP Canonical Address Format        February 2026

      Reencap Hop is REQUIRED to be used.  If this bit is 0, the re-
      encapsulator MAY skip this Reencap Hop and go to the next one in
      the list.

   AFI:  as specified in Section 4.1.  Only AFI values for IPv4 (1) and
      IPv6 (2) are valid in this LCAF Type.  Any other AFI value is
      invalid and the LCAF Type MUST be silently ignored.  All the AFI
      fields MUST be the same.  Otherwise, the LCAF Type MUST be
      silently ignored.

   Reencap Hop:  this is the address (as specified in Section 4.1) for
      reencapsulation.

   One or more Reencap Hops can be encoded in this LCAF.  Each hop is
   encoded with its own set of Reserved, L, P, S, AFI, and Address
   fields.

4.10.  The Security Key LCAF Type

   The Security Key LCAF Type (Type 11) is used to carry security key
   material when a locator in a locator-set has a security key
   associated with it.  See [I-D.ietf-lisp-8111bis] or [RFC8061] for an
   example.

    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 = 11   |      Rsvd2    |             Length            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Key Count   |    Reserved   | Key Algorithm |   Reserved  |R|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |           Key Length          |       Key Material ...        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        ... Key Material                       |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                AFI            |       Locator Address ...     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

           Figure 18: Security Key LISP Canonical Address Format

   Key Count:  the Key Count field declares the number of Key Sections
      included in this LCAF.  A Key Section is made up of the Key Length
      and Key Material fields.

   Reserved:  this field is reserved for future use and MUST be
      transmitted as 0 and ignored on receipt.

Retana, et al.           Expires 21 August 2026                [Page 19]
Internet-Draft        LISP Canonical Address Format        February 2026

   Key Algorithm:  the Key Algorithm field identifies the key's
      cryptographic algorithm and specifies the format of the Public Key
      field.  Specific use cases can specify the values for the
      supported algorithms.  Refer to [RFC8061] for an example.

   R bit:  this is the Revoke bit and, if set, it specifies that this
      key is being revoked.

   Key Length:  this field determines the length in octets of the Key
      Material field.

   Key Material:  this field stores the key material.  The format of the
      key material stored depends on the Key Algorithm field.

   AFI:  as specified in Section 4.1.  Only AFI values for IPv4 (1) and
      IPv6 (2) are valid in this LCAF Type.  Any other AFI value is
      invalid and the LCAF Type MUST be silently ignored.

   Locator Address:  this is the address (as specified in Section 4.1)
      that owns the encoded security key.

4.11.  The Source/Destination LCAF Type

   The Source/Destination LCAF Type (Type 12) is used to carry a source
   and destination address pair.

   For example, when both a source and destination address of a flow
   need consideration for different locator-sets, this 2-tuple key is
   used in EID fields in LISP control messages.  When the Source/Dest
   key is registered to the mapping database, it can be encoded as a
   source- prefix and destination-prefix.  When the Source/Dest is used
   as a key for a mapping database lookup, the source and destination
   come from a data packet.  Refer to [I-D.ietf-lisp-te] for an example
   of its use.

    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 = 12   |     Rsvd2     |             Length            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Reserved           |   Source-ML   |    Dest-ML    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                AFI            |         Source-Prefix ...     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                AFI            |     Destination-Prefix ...    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Retana, et al.           Expires 21 August 2026                [Page 20]
Internet-Draft        LISP Canonical Address Format        February 2026

        Figure 19: Source/Destination LISP Canonical Address Format

   Reserved:  this field is reserved for future use and MUST be
      transmitted as 0 and ignored on receipt.

   Source-ML:  the mask length of the Source Prefix that follows.  The
      length is the number of high-order mask bits set.

   Dest-ML:  the mask length of the Destination Prefix that follows.
      The length is the number of high-order mask bits set.

   AFI:  as specified in Section 4.1.  Only AFI values for IPv4 (1) and
      IPv6 (2) are valid in this LCAF Type.  Any other AFI value is
      invalid and the LCAF Type MUST be silently ignored.  All the AFI
      fields MUST be the same.  Otherwise, the LCAF Type MUST be
      silently ignored.

   Source-Prefix:  the source address prefix (as specified in
      Section 4.1).

   Destination-Prefix:  the destination address prefix (as specified in
      Section 4.1).

4.12.  The Replication List LCAF Type

   The Replication List LCAF Type (Type 13) is used to carry a list of
   locators for unicast replication.  See [I-D.coras-lisp-re] for an
   example.

    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 = 13   |    Rsvd2      |             Length            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Reserved                 |  Level Value  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                AFI            |           RTR/ETR #1 ...      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Reserved                 |  Level Value  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                AFI            |           RTR/ETR  #n ...     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      Figure 20: Replication List Entry LISP Canonical Address Format

   Reserved:  this field is reserved for future use and MUST be

Retana, et al.           Expires 21 August 2026                [Page 21]
Internet-Draft        LISP Canonical Address Format        February 2026

      transmitted as 0 and ignored on receipt.

   Level Value:  this value is associated with the level within the
      overlay distribution tree hierarchy where the RTR resides.  See
      [I-D.coras-lisp-re] for an example.

   AFI:  as specified in Section 4.1.  Only AFI values for IPv4 (1) and
      IPv6 (2) are valid in this LCAF Type.  Any other AFI value is
      invalid and the LCAF Type MUST be silently ignored.  All the AFI
      fields MUST be the same.  Otherwise, the LCAF Type MUST be
      silently ignored.

   RTR/ETR:  the address (as specified in Section 4.1) of the Re-
      encapsulating Tunnel Router (RTR) or Egress Tunnel Router (ETR)
      participating in the overlay distribution tree.  Can be either a
      unicast or multicast address.

   One or more RTR/ETR values can be encoded in this LCAF.  Each one is
   encoded with its own set of Reserved, Level Value, AFI, and RTR/ETR
   fields.

4.13.  The JSON Data Model LCAF Type

   The JSON Data Model LCAF Type (Type 14) is used to carry a JavaScript
   Object Notation (JSON) data model that can be encoded as either an
   EID or an RLOC.

    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 = 14   |    Rsvd2    |B|            Length             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |           JSON length         |             JSON ...          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                AFI            |       Optional Address ...    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

          Figure 21: JSON Data Model LISP Canonical Address Format

   B bit:  indicates that the JSON field is binary encoded according to
      [JSON-BINARY] when the bit is set to 1.  Otherwise, the encoding
      is based on text encoding according to [RFC8259].

      The rest of the Rsvd2 field is as specified in Section 3

   JSON length:  length in octets of the JSON field.

Retana, et al.           Expires 21 August 2026                [Page 22]
Internet-Draft        LISP Canonical Address Format        February 2026

   JSON:  a variable-length field that contains either binary or text
      encodings.

   AFI:  as specified in Section 4.1.

   Optional Address:  an address (as specified in Section 4.1) that can
      be associated with the JSON data model.

   An example mapping is an EID-record encoded as a distinguished-name
   "cpe-router" and an RLOC-record encoded as a JSON string "{ "router-
   address" : "192.0.2.1", "router-mask" : "24" }".

4.14.  The Key/Value Address Pair LCAF Type

   The Key/Value Address Pair LCAF Type (Type 15) is used to carry a
   key/value address pair.  This LCAF Type can be useful, for example,
   when attaching attributes to other elements of LISP packets, such as
   EIDs or RLOCs.

    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 = 15   |     Rsvd2     |            Length             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                AFI            |       Address as Key ...      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                AFI            |       Address as Value ...    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      Figure 22: Key/Value Address Pair LISP Canonical Address Format

   AFI:  as specified in Section 4.1.  All the AFI fields MUST be the
      same.  Otherwise, the LCAF Type MUST be silently ignored.

   Address as Key:  an address (as specified in Section 4.1) that will
      be attached with the attributes associated with the Address as
      Value field.

   Address as Value:  an address (as specified in Section 4.1) that will
      be the attribute address for the Address as Key field.

4.15.  The Encapsulation Format LCAF Type

   The Encapsulation Format LCAF Type (Type 16) is used to advertise the
   encapsulation formats supported by an RLOC.

Retana, et al.           Expires 21 August 2026                [Page 23]
Internet-Draft        LISP Canonical Address Format        February 2026

    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 = 16   |     Rsvd2     |             Length            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                    Encapsulations               |U|G|N|v|V|l|L|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                AFI            |          Address ...          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

       Figure 23: Encapsulation Format LISP Canonical Address Format

   Encapsulations:  the bits in this field are reserved for future use
      and MUST be transmitted as 0 and ignored on receipt.

   U:  The RLOC listed in the Address field can accept Generic UDP
      Encapsulation (GUE) using destination UDP port 6080
      [I-D.ietf-intarea-gue].

   G:  The RLOCs listed in the Address field can accept Geneve
      encapsulation using destination UDP port 6081 [RFC8926].

   N:  The RLOCs listed in the Address field can accept NV-GRE (Network
      Virtualization - Generic Routing Encapsulation) using IPv4/IPv6
      protocol number 47 [RFC7637].

   v:  The RLOCs listed in the Address field can accept VXLAN-GPE
      (Generic Protocol Extension) encapsulation using destination UDP
      port 4790 [I-D.ietf-nvo3-vxlan-gpe].

   V:  The RLOCs listed in the Address field can accept Virtual
      eXtensible Local Area Network (VXLAN) encapsulation using
      destination UDP port 4789 [RFC7348].

   l:  The RLOCs listed in the Address field can accept Layer 2 LISP
      encapsulation using destination UDP port 8472
      [I-D.smith-lisp-layer2].

   L:  The RLOCs listed in the Address field can accept Layer 3 LISP
      encapsulation using destination UDP port 4341 [RFC9300].

   AFI:  as specified in Section 4.1.  Only AFI values for IPv4 (1) and
      IPv6 (2) are valid in this LCAF Type.  Any other AFI value is
      invalid and the LCAF Type MUST be silently ignored.

   Address:  as specified in Section 4.1.

Retana, et al.           Expires 21 August 2026                [Page 24]
Internet-Draft        LISP Canonical Address Format        February 2026

4.16.  The Vendor-Specific LCAF Type

   The Vendor-Specific LCAF (Type 255) enables organizations to have
   implementation-specific encodings for LCAF addresses.  It relies on
   using the IEEE Organizationally Unique Identifier (OUI) [IEEE.802] to
   prevent collisions across vendors or organizations using the LCAF.

    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 = 255  |     Rsvd2     |            Length             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Reserved    |    Organizationally Unique Identifier (OUI)   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        Internal format...                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

          Figure 24: Vendor-Specific LISP Canonical Address Format

   Reserved:  this field is reserved for future use and MUST be
      transmitted as 0 and ignored on receipt.

   Organizationally Unique Identifier (OUI):  a 24-bit field that
      carries an OUI or Company ID (CID) assigned by the IEEE
      Registration Authority (RA) as defined by the IEEE Std 802
      [IEEE.802]

   Internal format:  variable-length field that each vendor or
      organization can define to use with their specific OUI.

   The Vendor-Specific LCAF type SHOULD NOT be used in deployments where
   different organizations interoperate.  However, there may be cases
   where two (or more) organizations share a common deployment on which
   they explicitly and mutually agree to use a particular Vendor-
   Specific LCAF.  In that case, the organizations involved need to
   carefully assess the interoperability concerns for that particular
   deployment.  It is NOT RECOMMENDED to use an OUI not assigned to an
   organization.

   If a LISP device receives a LISP message containing a Vendor-Specific
   LCAF with an OUI that it does not understand, it MUST silently ignore
   it.

Retana, et al.           Expires 21 August 2026                [Page 25]
Internet-Draft        LISP Canonical Address Format        February 2026

5.  Security Considerations

   The security considerations discussed in [RFC9300], [RFC9301], and
   [RFC9303] apply to the LCAF encodings defined in this document and
   their use.  An in-depth threat analysis of LISP is provided in
   [RFC7835].

   The LCAF encodings defined in this document are intended to be used
   with their corresponding use cases and in self-contained
   environments.  Users should carefully consider and document
   additional considerations that may result from their particular use
   case.  As with any protocol extension, the addition of new LCAF Types
   increases the attack surface of the protocol.  Implementers and
   operators should be aware of this when deploying new LCAF Types.

   This document also enables organizations to define new LCAFs for
   their internal use.  It is the responsibility of these organizations
   to properly assess the security implications of the formats they
   define.

   Care should be taken to protect against the adverse use of
   information that should remain private or contained by ensuring
   policy controls are in place.  Any such mechanism is out of scope for
   this document.

   Additionally, implementers should ensure that proper validation and
   error handling are in place for all LCAF Types to prevent potential
   attacks such as malformed data injections.

6.  IANA Considerations

   Because this document obsoletes RFC 8060 and RFC 9306, IANA is asked
   to change all registration information that references [RFC8060] or
   [RFC9306] to instead reference [[this RFC]].

   IANA is also requested to update the contents of the "LISP Canonical
   Address Format (LCAF) Types" registry as indicated in Table 2.
   Future assignments are to be made using the Specification Required
   policy [RFC8126].  Assignments consist of a LISP LCAF Type Name and
   its associated value:

Retana, et al.           Expires 21 August 2026                [Page 26]
Internet-Draft        LISP Canonical Address Format        February 2026

        +=======+========================+========================+
        | Value | LISP LCAF Type Name    | Reference              |
        +=======+========================+========================+
        | 0     | Null Body              | [[this RFC],Section 3] |
        +-------+------------------------+------------------------+
        | 1     | AFI List               | [[this RFC],Section 3] |
        +-------+------------------------+------------------------+
        | 2     | Instance ID            | [[this RFC],Section 3] |
        +-------+------------------------+------------------------+
        | 3     | AS Number              | [[this RFC],Section 3] |
        +-------+------------------------+------------------------+
        | 4     | Application Data       | [[this RFC],Section 3] |
        +-------+------------------------+------------------------+
        | 5     | Deprecated             | [I-D.ietf-lisp-geo]    |
        +-------+------------------------+------------------------+
        | 6     | Opaque Key             | [[this RFC],Section 3] |
        +-------+------------------------+------------------------+
        | 7     | NAT-Traversal          | [[this RFC],Section 3] |
        +-------+------------------------+------------------------+
        | 8     | Nonce Locator          | [[this RFC],Section 3] |
        +-------+------------------------+------------------------+
        | 9     | Multicast Info         | [[this RFC],Section 3] |
        +-------+------------------------+------------------------+
        | 10    | Explicit Locator Path  | [[this RFC],Section 3] |
        +-------+------------------------+------------------------+
        | 11    | Security Key           | [[this RFC],Section 3] |
        +-------+------------------------+------------------------+
        | 12    | Source/Dest Key        | [[this RFC],Section 3] |
        +-------+------------------------+------------------------+
        | 13    | Replication List Entry | [[this RFC],Section 3] |
        +-------+------------------------+------------------------+
        | 14    | JSON Data Model        | [[this RFC],Section 3] |
        +-------+------------------------+------------------------+
        | 15    | Key/Value Address Pair | [[this RFC],Section 3] |
        +-------+------------------------+------------------------+
        | 16    | Encapsulation Format   | [[this RFC],Section 3] |
        +-------+------------------------+------------------------+
        | 255   | Vendor-Specific        | [[this RFC],Section 3] |
        +-------+------------------------+------------------------+

           Table 2: "LISP Canonical Address Format (LCAF) Types"
                                  Registry

   IANA is also requested to update the description for AFI 16387 in the
   "Address Family Numbers" registry [AFN] to reference [[this RFC]].

7.  References

Retana, et al.           Expires 21 August 2026                [Page 27]
Internet-Draft        LISP Canonical Address Format        February 2026

7.1.  Normative References

   [IEEE.802] IEEE, "IEEE Standard for Local and Metropolitan Area
              Networks: Overview and Architecture",
              DOI 10.1109/IEEESTD.2014.6847097, IEEE Std 802, July 2014,
              <https://ieeexplore.ieee.org/document/6847097>.

   [JSON-BINARY]
              "Universal Binary JSON Specification",
              <http://ubjson.org>.

   [RFC768]   Postel, J., "User Datagram Protocol", STD 6, RFC 768,
              DOI 10.17487/RFC0768, August 1980,
              <https://www.rfc-editor.org/info/rfc768>.

   [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>.

   [RFC6793]  Vohra, Q. and E. Chen, "BGP Support for Four-Octet
              Autonomous System (AS) Number Space", RFC 6793,
              DOI 10.17487/RFC6793, December 2012,
              <https://www.rfc-editor.org/info/rfc6793>.

   [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>.

   [RFC8259]  Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
              Interchange Format", STD 90, RFC 8259,
              DOI 10.17487/RFC8259, December 2017,
              <https://www.rfc-editor.org/info/rfc8259>.

   [RFC8926]  Gross, J., Ed., Ganga, I., Ed., and T. Sridhar, Ed.,
              "Geneve: Generic Network Virtualization Encapsulation",
              RFC 8926, DOI 10.17487/RFC8926, November 2020,
              <https://www.rfc-editor.org/info/rfc8926>.

   [RFC9260]  Stewart, R., Tüxen, M., and K. Nielsen, "Stream Control
              Transmission Protocol", RFC 9260, DOI 10.17487/RFC9260,
              June 2022, <https://www.rfc-editor.org/info/rfc9260>.

Retana, et al.           Expires 21 August 2026                [Page 28]
Internet-Draft        LISP Canonical Address Format        February 2026

   [RFC9293]  Eddy, W., Ed., "Transmission Control Protocol (TCP)",
              STD 7, RFC 9293, DOI 10.17487/RFC9293, August 2022,
              <https://www.rfc-editor.org/info/rfc9293>.

   [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>.

7.2.  Informative References

   [AFN]      IANA, "Address Family Numbers",
              <http://www.iana.org/assignments/address-family-numbers/>.

   [I-D.coras-lisp-re]
              Coras, F., Cabellos-Aparicio, A., Domingo-Pascual, J.,
              Maino, F., and D. Farinacci, "LISP Replication
              Engineering", Work in Progress, Internet-Draft, draft-
              coras-lisp-re-08, 1 November 2015,
              <https://datatracker.ietf.org/doc/html/draft-coras-lisp-
              re-08>.

   [I-D.farinacci-lisp-lispers-net-nat]
              Farinacci, D., "lispers.net LISP NAT-Traversal
              Implementation Report", Work in Progress, Internet-Draft,
              draft-farinacci-lisp-lispers-net-nat-11, 30 November 2025,
              <https://datatracker.ietf.org/doc/html/draft-farinacci-
              lisp-lispers-net-nat-11>.

   [I-D.ietf-intarea-gue]
              Herbert, T., Yong, L., and O. Zia, "Generic UDP
              Encapsulation", Work in Progress, Internet-Draft, draft-
              ietf-intarea-gue-09, 26 October 2019,
              <https://datatracker.ietf.org/doc/html/draft-ietf-intarea-
              gue-09>.

Retana, et al.           Expires 21 August 2026                [Page 29]
Internet-Draft        LISP Canonical Address Format        February 2026

   [I-D.ietf-lisp-8111bis]
              Iannone, L. and L. Jakab, "Locator/ID Separation Protocol
              Delegated Database Tree (LISP-DDT)", Work in Progress,
              Internet-Draft, draft-ietf-lisp-8111bis-00, 3 September
              2025, <https://datatracker.ietf.org/doc/html/draft-ietf-
              lisp-8111bis-00>.

   [I-D.ietf-lisp-nat-traversal]
              Iannone, L., "NAT traversal for LISP", Work in Progress,
              Internet-Draft, draft-ietf-lisp-nat-traversal-01, 16
              February 2026, <https://datatracker.ietf.org/doc/html/
              draft-ietf-lisp-nat-traversal-01>.

   [I-D.ietf-lisp-geo]
              Farinacci, D., "LISP Geo-Coordinates", Work in Progress,
              Internet-Draft, draft-ietf-lisp-geo-18, 22 July 2025,
              <https://datatracker.ietf.org/doc/html/draft-ietf-lisp-
              geo-18>.

   [I-D.ietf-lisp-eid-mobility]
              Portoles-Comeras, M., Ashtaputre, V., Maino, F., Moreno,
              V., and D. Farinacci, "LISP L2/L3 EID Mobility Using a
              Unified Control Plane", Work in Progress, Internet-Draft,
              draft-ietf-lisp-eid-mobility-17, 20 October 2025,
              <https://datatracker.ietf.org/doc/html/draft-ietf-lisp-
              eid-mobility-17>.

   [I-D.ietf-lisp-te]
              Farinacci, D., Kowal, M., Lahiri, P., and P. Pillay-
              Esnault, "LISP Traffic Engineering", Work in Progress,
              Internet-Draft, draft-ietf-lisp-te-25, 15 February 2026,
              <https://datatracker.ietf.org/doc/html/draft-ietf-lisp-te-
              25>.

   [I-D.ietf-lisp-vpn]
              Moreno, V. and D. Farinacci, "LISP Virtual Private
              Networks (VPNs)", Work in Progress, Internet-Draft, draft-
              ietf-lisp-vpn-13, 3 November 2025,
              <https://datatracker.ietf.org/doc/html/draft-ietf-lisp-
              vpn-13>.

   [I-D.ietf-nvo3-vxlan-gpe]
              Maino, F., Kreeger, L., and U. Elzur, "Generic Protocol
              Extension for VXLAN (VXLAN-GPE)", Work in Progress,
              Internet-Draft, draft-ietf-nvo3-vxlan-gpe-13, 4 November
              2023, <https://datatracker.ietf.org/doc/html/draft-ietf-
              nvo3-vxlan-gpe-13>.

Retana, et al.           Expires 21 August 2026                [Page 30]
Internet-Draft        LISP Canonical Address Format        February 2026

   [I-D.smith-lisp-layer2]
              Smith, M., Dutt, D., Farinacci, D., and F. Maino, "Layer 2
              (L2) LISP Encapsulation Format", Work in Progress,
              Internet-Draft, draft-smith-lisp-layer2-03, 6 September
              2013, <https://datatracker.ietf.org/doc/html/draft-smith-
              lisp-layer2-03>.

   [RFC1035]  Mockapetris, P., "Domain names - implementation and
              specification", STD 13, RFC 1035, DOI 10.17487/RFC1035,
              November 1987, <https://www.rfc-editor.org/info/rfc1035>.

   [RFC2475]  Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z.,
              and W. Weiss, "An Architecture for Differentiated
              Services", RFC 2475, DOI 10.17487/RFC2475, December 1998,
              <https://www.rfc-editor.org/info/rfc2475>.

   [RFC3986]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
              Resource Identifier (URI): Generic Syntax", STD 66,
              RFC 3986, DOI 10.17487/RFC3986, January 2005,
              <https://www.rfc-editor.org/info/rfc3986>.

   [RFC4607]  Holbrook, H. and B. Cain, "Source-Specific Multicast for
              IP", RFC 4607, DOI 10.17487/RFC4607, August 2006,
              <https://www.rfc-editor.org/info/rfc4607>.

   [RFC6832]  Lewis, D., Meyer, D., Farinacci, D., and V. Fuller,
              "Interworking between Locator/ID Separation Protocol
              (LISP) and Non-LISP Sites", RFC 6832,
              DOI 10.17487/RFC6832, January 2013,
              <https://www.rfc-editor.org/info/rfc6832>.

   [RFC6836]  Fuller, V., Farinacci, D., Meyer, D., and D. Lewis,
              "Locator/ID Separation Protocol Alternative Logical
              Topology (LISP+ALT)", RFC 6836, DOI 10.17487/RFC6836,
              January 2013, <https://www.rfc-editor.org/info/rfc6836>.

   [RFC7348]  Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger,
              L., Sridhar, T., Bursell, M., and C. Wright, "Virtual
              eXtensible Local Area Network (VXLAN): A Framework for
              Overlaying Virtualized Layer 2 Networks over Layer 3
              Networks", RFC 7348, DOI 10.17487/RFC7348, August 2014,
              <https://www.rfc-editor.org/info/rfc7348>.

   [RFC7637]  Garg, P., Ed. and Y. Wang, Ed., "NVGRE: Network
              Virtualization Using Generic Routing Encapsulation",
              RFC 7637, DOI 10.17487/RFC7637, September 2015,
              <https://www.rfc-editor.org/info/rfc7637>.

Retana, et al.           Expires 21 August 2026                [Page 31]
Internet-Draft        LISP Canonical Address Format        February 2026

   [RFC7761]  Fenner, B., Handley, M., Holbrook, H., Kouvelas, I.,
              Parekh, R., Zhang, Z., and L. Zheng, "Protocol Independent
              Multicast - Sparse Mode (PIM-SM): Protocol Specification
              (Revised)", STD 83, RFC 7761, DOI 10.17487/RFC7761, March
              2016, <https://www.rfc-editor.org/info/rfc7761>.

   [RFC7835]  Saucez, D., Iannone, L., and O. Bonaventure, "Locator/ID
              Separation Protocol (LISP) Threat Analysis", RFC 7835,
              DOI 10.17487/RFC7835, April 2016,
              <https://www.rfc-editor.org/info/rfc7835>.

   [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>.

   [RFC8061]  Farinacci, D. and B. Weis, "Locator/ID Separation Protocol
              (LISP) Data-Plane Confidentiality", RFC 8061,
              DOI 10.17487/RFC8061, February 2017,
              <https://www.rfc-editor.org/info/rfc8061>.

   [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>.

Acknowledgements

   The authors would like to thank all the people who have provided
   feedback on the various LCAF Types over the years.

   In no particular order, the authors would like to thank Vince Fuller,
   Gregg Schudel, Jesper Skriver, Luigi Iannone, Isidor Kouvelas, Sander
   Steffann, Victor Moreno, Parantap Lahiri, Michael Kowal, Fabio Maino,
   Albert Cabellos-Aparicio, Michiel Blokzijl, Terry Manderson, Stephen
   Farrell, Deborah Brungard, and Joel Halpern.

Contributors

   The following people have made significant contributions to the
   content of this document.

   Dave Meyer
   Individual Contributor
   Email: [email protected]

   Vina Ermagan
   Google, Inc.

Retana, et al.           Expires 21 August 2026                [Page 32]
Internet-Draft        LISP Canonical Address Format        February 2026

   Email: [email protected]

   Anton Smirnov
   Cisco
   Email: [email protected]

   Vrushali Ashtaputre
   Cisco
   Email: [email protected]

Appendix A: Change Log

   This section is to be removed before publishing as an RFC.

Version -00

   This initial version is the same as RFC8060, but with updated
   references and using the rfcxmlv3 formatting.

Version -01

   *  Incorporated Errata ID: 7252 (https://www.rfc-editor.org/errata/
      eid7252).

   *  Eliminated mentions of "experiment" and "unapproved" by moving
      LCAFs defined in the section titled "Experimental LISP Canonical
      Address Applications" into the main section (Section 4).

   *  Eliminated Geo-Coordinates.

   *  Updated the IANA Considerations table with the full list of Types.

   *  Eliminated the reference to RFC 3232 ("RFC 1700 Replaced by On-
      line Database"), which didn't provide context for AFI.

   *  Moved the reference to RFC 6836 to be Informative; in the text it
      is used as an example.  This addresses the downref.

   *  To avoid a downref, moved the references to RFC 7348 and RFC 7637
      to be Informative.  This is inline with the other references for
      similar functionality in the Encapsulation Format LCAF
      (Section 4.15)

Version -02

Retana, et al.           Expires 21 August 2026                [Page 33]
Internet-Draft        LISP Canonical Address Format        February 2026

   *  Eliminated a couple remaining mentions of Geo-Coordinates.

Version -03

   *  Updated authors and contributors.

   *  Focus the text on the encodings, not the use cases/applications.

   *  Included terminology by reference.

   *  Consolidated the acknowledgements.

   *  Other editorial improvements.

Version -04

   *  Merged the contents of RFC 9306 into this document.

Authors' Addresses

   Alvaro Retana (editor)
   Futurewei Technologies, Inc.
   Email: [email protected]

   Dino Farinacci
   lispers.net
   Email: [email protected]

   Job Snijders
   Email: [email protected]

   Alberto Rodriguez-Natal
   Cisco
   Barcelona
   Spain
   Email: [email protected]

Retana, et al.           Expires 21 August 2026                [Page 34]