wdiff draft-ietf-lisp-lcaf-04.txt = draft-ietf-lisp-lcaf-05.txt

Network Working Group                                       D. Farinacci
Internet-Draft                                               lispers.net
Intended status: Experimental                                   D. Meyer
Expires: July 31, =
November 7, 2014           =
                             Brocade
                                                             J. Snijders
                                                       Hibernia Networks
                                                        January 27,
                                                             =
May 6, 2014

                  LISP Canonical Address Format (LCAF)
                        draft-ietf-lisp-lcaf-04
                        draft-ietf-lisp-lcaf-05

Abstract

   This draft defines a canonical address format encoding used in LISP
   control messages and in the encoding of lookup keys for the LISP
   Mapping Database System.

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 http://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 July =
31, November =
7, 2014.

Copyright Notice

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
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   described in the Simplified BSD License.

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Definition of Terms  . . . . . . . . . . . . . . . . . . . . .  4
   3.  LISP Canonical Address Format Encodings  . . . . . . . . . . .  5
   4.  LISP Canonical Address Applications  . . . . . . . . . . . . .  7
     4.1.  Segmentation using LISP  . . . . . . . . . . . . . . . . .  7
     4.2.  Carrying AS Numbers in the Mapping Database  . . . . . . .  8
     4.3.  Convey Application Specific Data . . . . . . . . . . . . .  9
     4.4.  Assigning Geo Coordinates to Locator Addresses . . . . . . 10
     4.5.  Generic Database Mapping Lookups . . . . . . . . . . . . . 12
     4.6.  NAT Traversal Scenarios  . . . . . . . . . . . . . . . . . 13
     4.7.  PETR Admission Control Functionality . . . . . . . . . . . 15
     4.8.  Multicast Group Membership Information . . . . . . . . . . 16
     4.9.  Traffic Engineering using Re-encapsulating Tunnels . . . . 18
     4.10. Storing Security Data in the Mapping Database  . . . . . . 19
     4.11. Source/Destination 2-Tuple Lookups . . . . . . . . . . . . 20
     4.12. Replication List Entries for Multicast Forwarding  . . . . 21
     4.13. Data Model Encoding  . . . . . . . . . . . . . . . . . . . 22
     4.14. Encoding Key/Value Address Pairs . . . . . . . . . . . . . 23
     4.15. Applications for AFI List Type . . . . . . . . . . . . . . 23
       4.15.1.  Binding IPv4 and IPv6 Addresses . . . . . . . . . . . 23
       4.15.2.  Layer-2 VPNs  . . . . . . . . . . . . . . . . . . . . 25
       4.15.3.  ASCII Names in the Mapping Database . . . . . . . . . 25
       4.15.4.  Using Recursive LISP Canonical Address Encodings  . . 26
       4.15.5.  Compatibility Mode Use Case . . . . . . . . . . . . . 27
   5.  Security Considerations  . . . . . . . . . . . . . . . . . . . 28
   6.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 29
   7.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 30
     7.1.  Normative References . . . . . . . . . . . . . . . . . . . 30
     7.2.  Informative References . . . . . . . . . . . . . . . . . . 30
   Appendix A.  Acknowledgments . . . . . . . . . . . . . . . . . . . 32
   Appendix B.  Document Change Log . . . . . . . . . . . . . . . . . 33
     B.1.  Changes to draft-ietf-lisp-lcaf-04.txt draft-ietf-lisp-lcaf-05.txt . . . . . . =
. . . . 33
     B.2.  Changes to draft-ietf-lisp-lcaf-03.txt draft-ietf-lisp-lcaf-04.txt . . . . . . =
. . . . 33
     B.3.  Changes to draft-ietf-lisp-lcaf-02.txt draft-ietf-lisp-lcaf-03.txt . . . . . . =
. . . . 33
     B.4.  Changes to draft-ietf-lisp-lcaf-01.txt draft-ietf-lisp-lcaf-02.txt . . . . . . =
. . . . 33
     B.5.  Changes to draft-ietf-lisp-lcaf-00.txt draft-ietf-lisp-lcaf-01.txt . . . . . . =
. . . . 33
     B.6.  Changes to =
draft-ietf-lisp-lcaf-00.txt . . . . . . . . . . 34
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 35

1.  Introduction

   The LISP architecture and protocols [RFC6830] introduces two new
   numbering spaces, Endpoint Identifiers (EIDs) and Routing Locators
   (RLOCs) which are intended to replace most use of IP addresses on the
   Internet.  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.

   Currently defined AFIs include IPv4 and IPv6 addresses, which are
   formatted according to code-points assigned in [AFI] as follows:

   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 =3D 1            |       IPv4 Address ...        |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |     ...  IPv4 Address         |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   IPv6 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 =3D 2            |       IPv6 Address ...        |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     ...  IPv6 Address  ...                    |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     ...  IPv6 Address  ...                    |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     ...  IPv6 Address  ...                    |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |     ...  IPv6 Address         |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   This document describes the currently-defined AFIs the LISP protocol
   uses 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.

2.  Definition of Terms

   Address Family Identifier (AFI):  a term used to describe an address
      encoding in a packet.  An address family currently defined for
      IPv4 or IPv6 addresses.  See [AFI] and [RFC1700] for details.  The
      reserved AFI value of 0 is used in this specification to indicate
      an unspecified encoded address where the the length of the address
      is 0 bytes following the 16-bit AFI value of 0.

   Unspecified Address Format:

     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 =3D 0            |    <nothing follows AFI=3D0>=
    |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Endpoint ID (EID):   a 32-bit (for IPv4) or 128-bit (for IPv6) value
      used in the source and destination address fields of the first
      (most inner) LISP header of a packet.  The host obtains a
      destination EID the same way it obtains a destination address
      today, for example through a DNS lookup or SIP exchange.  The
      source EID is obtained via existing mechanisms used to set a
      host's "local" IP address.  An EID is allocated to a host from an
      EID-prefix block associated with the site where the host is
      located.  An EID can be used by a host to refer to other hosts.

   Routing Locator (RLOC):   the IPv4 or IPv6 address of an egress
      tunnel router (ETR).  It is the output of a EID-to-RLOC mapping
      lookup.  An EID maps to one or more RLOCs.  Typically, RLOCs are
      numbered from topologically aggregatable blocks that are assigned
      to a site at each point to which it attaches to the global
      Internet; where the topology is defined by the connectivity of
      provider networks, RLOCs can be thought of as PA addresses.
      Multiple RLOCs can be assigned to the same ETR device or to
      multiple ETR devices at a site.

3.  LISP Canonical Address Format Encodings

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

   The first 4 bytes of an LISP Canonical Address are followed by a
   variable length of fields:

     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 =3D 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |    Type       |     Rsvd2     |            Length             |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Rsvd1:  this 8-bit 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.  For now,
      set to zero on transmission and ignored on receipt.

   Type:  this 8-bit field is specific to the LISP Canonical Address
      formatted encodings, values are:

     Type 0:  Null Body Type

     Type 1:  AFI List Type

     Type 2:  Instance ID Type

     Type 3:  AS Number Type

     Type 4:  Application Data Type

     Type 5:  Geo Coordinates Type

     Type 6:  Opaque Key Type

     Type 7:  NAT-Traversal Type

     Type 8:  Nonce Locator Type

     Type 9:  Multicast Info Type
     Type 10:  Explicit Locator Path Type

     Type 11:  Security Key Type

     Type 12:  Source/Dest Key Type

     Type 13:  Replication List Entry Type

     Type 14:  JSON Data Model Type

     Type 15:  Key/Value Address Pair Type

   Rsvd2:  this 8-bit field is reserved for future use and MUST be
      transmitted as 0 and ignored on receipt.

   Length:  this 16-bit field is in units of bytes and covers all of the
      LISP Canonical Address payload, starting and including the byte
      after the Length field.  So any LCAF encoded address will have a
      minimum length of 8 bytes when the Length field is 0.  The 8 bytes
      include the AFI, Flags, Type, Reserved, and Length fields.  When
      the AFI is not next to encoded address in a control message, then
      the encoded address will have a minimum length of 6 bytes when the
      Length field is 0.  The 6 bytes include the Flags, Type, Reserved,
      and Length fields.

4.  LISP Canonical Address Applications

4.1.  Segmentation using LISP

   When multiple organizations inside of a LISP site are using private
   addresses [RFC1918] as EID-prefixes, their address spaces must remain
   segregated due to possible address duplication.  An Instance ID in
   the address encoding can aid in making the entire AFI based address
   unique.

   Another use for the Instance ID LISP Canonical Address Format is when
   creating multiple segmented VPNs inside of a LISP site where keeping
   EID-prefix based subnets is desirable.

   Instance ID LISP Canonical Address Format:

     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 =3D 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Type =3D 2    | IID mask-len  |             4 + n             |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                         Instance ID                           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              AFI =3D x          |         Address  ...          |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   IID mask-len:  if the AFI is set to 0, then this format is not
      encoding an extended EID-prefix but rather an instance-ID range
      where the 'IID mask-len' indicates the number of high-order bits
      used in the Instance ID field for the range.

   Length value n:  length in bytes of the AFI address that follows the
      Instance ID field including the AFI field itself.

   Instance ID:  the low-order 24-bits that can go into a LISP data
      header when the I-bit is set.  See [RFC6830] for details.

   AFI =3D x:  x can be any AFI value from [AFI].

   This LISP Canonical Address Type can be used to encode either EID or
   RLOC addresses.

4.2.  Carrying AS Numbers in the Mapping Database

   When an AS number is stored in the LISP Mapping Database System for
   either policy or documentation reasons, it can be encoded in a LISP
   Canonical Address.

   AS Number LISP Canonical Address Format:

     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 =3D 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Type =3D 3    |     Rsvd2     |             4 + n             |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                           AS Number                           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              AFI =3D x          |         Address  ...          |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Length value n:  length in bytes of the AFI address that follows the
      AS Number field including the AFI field itself.

   AS Number:  the 32-bit AS number of the autonomous system that has
      been assigned either the EID or RLOC that follows.

   AFI =3D x:  x can be any AFI value from [AFI].

   The AS Number Canonical Address 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.

4.3.  Convey Application Specific Data

   When a locator-set needs to be conveyed based on the type of
   application or the Per-Hop Behavior (PHB) of a packet, the
   Application Data Type can be used.

   Application Data LISP Canonical Address Format:

     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 =3D 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Type =3D 4    |     Rsvd2     |             8 + n             |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |       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 =3D x          |         Address  ...          |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Length value n:  length in bytes of the AFI address that follows the
      8-byte Application Data fields including the AFI field itself.

   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 Flow
      Label used in an IPv6 header.

   Local Port/Remote Port Ranges:  these fields are from the TCP, UDP,
      or SCTP transport header.  A range can be specified by using a
      lower value and an upper value.  When a single port is encoded,
      the lower and upper value fields are the same.

   AFI =3D x:  x can be any AFI value from [AFI].

   The Application Data Canonical Address 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.

4.4.  Assigning Geo Coordinates to Locator Addresses

   If an ETR desires to send a Map-Reply describing the Geo Coordinates
   for each locator in its locator-set, it can use the Geo Coordinate
   Type to convey physical location information.

   Coordinates are specified using the WGS-84 (World Geodetic System)
   reference coordinate system [WGS-84].

   Geo Coordinate LISP Canonical Address Format:

     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 =3D 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Type =3D 5    |     Rsvd2     |            12 + n             |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |N|     Latitude Degrees        |    Minutes    |    Seconds    |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |E|     Longitude Degrees       |    Minutes    |    Seconds    |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                            Altitude                           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              AFI =3D x          |         Address  ...          |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Length value n:  length in bytes of the AFI address that follows the
      8-byte Longitude and Latitude fields including the AFI field
      itself.

   N: When set to 1 means North, otherwise South.

   Latitude Degrees:  Valid values range from 0 to 90 degrees above or
      below the equator (northern or southern hemisphere, respectively).

   Latitude Minutes:  Valid values range from 0 to 59.

   Latitude Seconds:  Valid values range from 0 to 59.

   E: When set to 1 means East, otherwise West.

   Longitude Degrees:  Value values are from 0 to 180 degrees right or
      left of the Prime Meridian.

   Longitude Minutes:  Valid values range from 0 to 59.

   Longitude Seconds:  Valid values range from 0 to 59.

   Altitude:  Height relative to sea level in meters.  This is a signed
      integer meaning that the altitude could be below sea level.  A
      value of 0x7fffffff indicates no Altitude value is encoded.

   AFI =3D x:  x can be any AFI value from [AFI].

   The Geo Coordinates Canonical Address Type can be used to encode
   either EID or RLOC addresses.  When used for EID encodings, you can
   determine the physical location of an EID along with the topological
   location by observing the locator-set.

4.5.  Generic Database Mapping Lookups

   When the LISP Mapping Database system holds information accessed by a
   generic formatted key (where the key is not the usual IPv4 or IPv6
   address), an opaque key may be desirable.

   Opaque Key LISP Canonical Address Format:

     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 =3D 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Type =3D 6    |     Rsvd2     |               n               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    | Key Field Num |      Key Wildcard Fields      |   Key . . .   |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                       . . . Key                               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Length value n:  length in bytes of the type's payload.  The value n
      is the number of bytes that follow this Length field.

   Key Field Num:  the number of fields (minus 1) the key can be broken
      up into.  The width of the fields are fixed length.  So for a key
      size of 8 bytes, with a Key Field Num of 4 allows 4 fields of 2
      bytes in length.  Valid values for this field range from 0 to 15
      supporting a maximum of 16 field separations.

   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 field in the key.
      Bit 0 (the low-order bit) in this bitfield corresponds the first
      field, right-justified in the key, bit 1 the second 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 is set to 0, then all bits of the key are used for
      the database lookup.

   Key:  the variable length key used to do a LISP Database Mapping
      lookup.  The length of the key is the value n (shown above) minus
      3.

4.6.  NAT Traversal Scenarios

   When a LISP system is conveying global address and mapped port
   information when traversing through a NAT device, the NAT-Traversal
   LCAF Type is used.  See [LISP-NATT] for details.

   NAT-Traversal Canonical Address Format:

     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 =3D 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Type =3D 7    |     Rsvd2     |             4 + n             |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |       MS UDP Port Number      |      ETR UDP Port Number      |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              AFI =3D x          |  Global ETR RLOC Address  ... |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              AFI =3D x          |       MS RLOC Address  ...    |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              AFI =3D x          | Private ETR RLOC Address  ... |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              AFI =3D x          |      RTR RLOC Address 1 ...   |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              AFI =3D x          |      RTR RLOC Address k ...   |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Length value n:  length in bytes of the AFI addresses that follows
      the UDP Port Number field including the AFI fields themselves.

   MS UDP Port Number:  this is the UDP port number of the Map-Server
      and is set to 4342.

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

   AFI =3D x:  x can be any AFI value from [AFI].

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

   MS RLOC Address:  this is the address 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 known to be a private
      address inserted in this LCAF format by a LISP router that resides
      on the private side of a NAT device.

   RTR RLOC Address:  this is an encapsulation address used by an ITR or
      PITR which 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 one or more NTR addresses
      supplied in these set of fields.  The number of NTRs encoded is
      determined by the LCAF length field.  When there are no NTRs
      supplied, the NTR fields can be omitted and reflected by the LCAF
      length field or an AFI of 0 can be used to indicate zero NTRs
      encoded.

4.7.  PETR Admission Control Functionality

   When a public PETR device wants to verify who is encapsulating to it,
   it can check for a specific nonce value in the LISP encapsulated
   packet.  To convey the nonce to admitted ITRs or PITRs, this LCAF
   format is used in a Map-Register or Map-Reply locator-record.

   Nonce Locator Canonical Address Format:

     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 =3D 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Type =3D 8    |     Rsvd2     |             4 + n             |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Reserved    |                  Nonce                        |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              AFI =3D x          |         Address  ...          |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Length value n:  length in bytes of the AFI address that follows the
      Nonce field including the AFI field itself.

   Reserved:  must be set to zero and ignore on receipt.

   Nonce:  this is a nonce value returned by an ETR in a Map-Reply
      locator-record to be used by an ITR or PITR when encapsulating to
      the locator address encoded in the AFI field of this LCAF type.

   AFI =3D x:  x can be any AFI value from [AFI].

4.8.  Multicast Group Membership Information

   Multicast group information can be published in the mapping database
   so a lookup on an EID based group address can return a replication
   list of group addresses or a unicast addresses for single replication
   or multiple head-end replications.  The intent of this type of
   unicast replication is to deliver packets to multiple ETRs at
   receiver LISP multicast sites.  The locator-set encoding for this EID
   record type can be a list of ETRs when they each register with "Merge
   Semantics".  The encoding can be a typical AFI encoded locator
   address.  When an RTR list is being registered (with multiple levels
   according to [LISP-RE]), the Replication List Entry LCAF type is used
   for locator encoding.

   This LCAF encoding can be used to send broadcast packets to all
   members of a subnet when each EIDs are away from their home subnet
   location.

   Multicast Info Canonical Address Format:

     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 =3D 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Type =3D 9    |  Rsvd2  |R|L|J|             8 + n             |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                         Instance-ID                           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |            Reserved           | Source MaskLen| Group MaskLen |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              AFI =3D x          |   Source/Subnet Address  ...  |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              AFI =3D x          |       Group Address  ...      |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Length value n:  length in bytes of fields that follow.

   Reserved:  must be set to zero and ignore on receipt.

   R-bit:  this is the RP-bit that represents PIM (S,G,RP-bit) multicast
      state.  This bit can be set for Joins (when the J-bit is set) or
      for Leaves (when the L-bit is set).  See [LISP-MRSIG] for more
      usage details.

   L-bit:  this is the Leave-Request bit and is used when this LCAF type
      is present in the destination EID-prefix field of a Map-Request.
      See [LISP-MRSIG] for details.

   J-bit:  this is the Join-Request bit and is used when this LCAF type
      is present in the destination EID-prefix field of a Map-Request.
      See [LISP-MRSIG] for details.  The J-bit MUST not be set when the
      L-bit is also set in the same LCAF block.  A receiver should not
      take any specific Join or Leave action when both bits are set.

   Instance ID:  the low-order 24-bits that can go into a LISP data
      header when the I-bit is set.  See [RFC6830] for details.  The use
      of the Instance-ID in this LCAF type is to associate a multicast
      forwarding entry for a given VPN.  The instance-ID describes the
      VPN and is registered to the mapping database system as a 3-tuple
      of (Instance-ID, S-prefix, G-prefix).

   Source MaskLen:  the mask length of the source prefix that follows.

   Group MaskLen:  the mask length of the group prefix that follows.

   AFI =3D x:  x can be any AFI value from [AFI].  When a specific AFI =
has
      its own encoding of a multicast address, this field must be either
      a group address or a broadcast address.

4.9.  Traffic Engineering using Re-encapsulating Tunnels

   For a given EID lookup into the mapping database, this LCAF format
   can be returned to provide a list of locators in an explicit re-
   encapsulation path.  See [LISP-TE] for details.

   Explicit Locator Path (ELP) Canonical Address Format:

     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 =3D 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Type =3D 10   |     Rsvd2     |               n               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |           Rsvd3         |L|P|S|           AFI =3D x             |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                         Reencap Hop 1  ...                    |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |           Rsvd3         |L|P|S|           AFI =3D x             |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                         Reencap Hop k  ...                    |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Length value n:  length in bytes of fields that follow.

   Lookup bit (L):  this is the Lookup bit used to indicate to the user
      of the ELP to not use this address for encapsulation but to look
      it up in the mapping database system to obtain an encapsulating
      RLOC address.

   RLOC-Probe bit (P):  this is the RLOC-probe bit which means the
      Reencap Hop allows RLOC-probe messages to be sent to it.  When the
      R-bit is set to 0, RLOC-probes must not be sent.  When a Reencap
      Hop is an anycast address then multiple physical Reencap Hops are
      using the same RLOC address.  In this case, RLOC-probes are not
      needed because when the closest RLOC address is not reachable
      another RLOC address can reachable.

   Strict bit (S):  this the strict bit which means the associated
      Rencap Hop is required to be used.  If this bit is 0, the
      reencapsulator can skip this Reencap Hop and go to the next one in
      the list.

   AFI =3D x:  x can be any AFI value from [AFI].  When a specific AFI =
has
      its own encoding of a multicast address, this field must be either
      a group address or a broadcast address.

4.10.  Storing Security Data in the Mapping Database

   When a locator in a locator-set has a security key associated with
   it, this LCAF format will be used to encode key material.  See
   [LISP-DDT] for details.

   Security Key Canonical Address Format:

     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 =3D 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Type =3D 11   |      Rsvd2    |             6 + n             |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Key Count   |      Rsvd3    | Key Algorithm |   Rsvd4     |R|
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |           Key Length          |       Key Material ...        |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                        ... Key Material                       |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              AFI =3D x          |       Locator Address ...     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Length value n:  length in bytes of fields that start with the Key
      Material field.

   Key Count:  the Key Count field declares the number of Key sections
      included in this LCAF.

   Key Algorithm:  the Algorithm field identifies the key's
      cryptographic algorithm and specifies the format of the Public Key
      field.

   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 bytes of the Key
      Material field.

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

   AFI =3D x:  x can be any AFI value from [AFI].This is the locator
      address that owns the encoded security key.

4.11.  Source/Destination 2-Tuple Lookups

   When both a source and destination address of a flow needs
   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.

   Source/Dest Key Canonical Address Format:

     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 =3D 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Type =3D 12   |     Rsvd2     |             4 + n             |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |            Reserved           |   Source-ML   |    Dest-ML    |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              AFI =3D x          |         Source-Prefix ...     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              AFI =3D x          |     Destination-Prefix ...    |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Length value n:  length in bytes of fields that follow.

   Reserved:  must be set to zero and ignore on receipt.

   Source-ML:  the mask length of the source prefix that follows.

   Dest-ML:  the mask length of the destination prefix that follows.

   AFI =3D x:  x can be any AFI value from [AFI].  When a specific AFI =
has
      its own encoding of a multicast address, this field must be either
      a group address or a broadcast address.

   Refer to [LISP-TE] for usage details.

4.12.  Replication List Entries for Multicast Forwarding

   The Replication List Entry LCAF type is an encoding for a locator
   being used for unicast replication according to the specification in
   [LISP-RE].  This locator encoding is pointed to by a Multicast Info
   LCAF Type and is registered by Re-encapsulating Tunnel Routers (RTRs)
   that are participating in an overlay distribution tree.  Each RTR
   will register its locator address and its configured level in the
   distribution tree.

   Replication List Entry Address Format:

     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 =3D 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Type =3D 13   |    Rsvd2      |             4 + n             |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              Rsvd3            |     Rsvd4     |  Level Value  |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              AFI =3D x          |           RTR/ETR #1 ...      |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              Rsvd3            |     Rsvd4     |  Level Value  |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              AFI =3D x          |           RTR/ETR  #n ...     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Length value n:  length in bytes of fields that follow.

   Rsvd{1,2,3,4}:  must be set to zero and ignore on receipt.

   Level Value:  this value is associated with the level within the
      overlay distribution tree hierarchy where the RTR resides.  The
      level numbers are ordered from lowest value being close to the ITR
      (meaning that ITRs replicate to level-0 RTRs) and higher levels
      are further downstream on the distribution tree closer to ETRs of
      multicast receiver sites.

   AFI =3D x:  x can be any AFI value from [AFI].  A specific AFI has =
its
      own encoding of either a unicast or multicast locator address.
      All RTR/ETR entries for the same level should be combined together
      by a Map-Server to avoid searching through the entire multi-level
      list of locator entries in a Map-Reply message.

4.13.  Data Model Encoding

   This type allows a JSON data model to be encoded either as an EID or
   RLOC.

   JSON Data Model Type Address Format:

     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 =3D 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Type =3D 14   |    Rsvd2    |B|               n               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |           JSON binary or =
text length         | JSON =
binary/text encoding ... |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              AFI =3D x          |       Optional Address ...    |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Length value n:  length in bytes of fields that follow.

   Rsvd{1,2}:  must be set to zero and ignore on receipt.

   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 [RFC4627].

   JSON length:  length in octets of the =
following 'JSON binary/text
      encoding' field.

   JSON binary/text encoding field:  a variable length =
field that
      contains either binary or text encodings.

   AFI =3D x:  x can be any AFI value from [AFI].  A specific AFI has =
its
      own encoding of either a unicast or multicast locator address.
      All RTR/ETR entries for the same level should be combined together
      by a Map-Server to avoid searching through the entire multi-level
      list of locator entries in a Map-Reply message.

4.14.  Encoding Key/Value Address Pairs

   The Key/Value pair is for example useful for attaching attributes to
   other elements of LISP packets, such as EIDs or RLOCs.  When
   attaching attributes to EIDs or RLOCs, it's necessary to distinguish
   between the element that should be used as EID or RLOC, and hence as
   key for lookups, and additional attributes.  This is especially the
   case when the difference cannot be determined from the types of the
   elements, such as when two IP addresses are being used.

   Key/Value Pair Address Format:

     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 =3D 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Type =3D 15   |     Rsvd2     |               n               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              AFI =3D x          |       Address as Key ...      |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              AFI =3D x          |       Address as Value ...    |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Length value n:  length in bytes of fields that follow.

   Rsvd{1,2}:  must be set to zero and ignore on receipt.

   AFI =3D x:  x can be any AFI value from [AFI].  A specific AFI has =
its
      own encoding of either a unicast or multicast locator address.
      All RTR/ETR entries for the same level should be combined together
      by a Map-Server to avoid searching through the entire multi-level
      list of locator entries in a Map-Reply message.

   Address as Key:  this AFI encoded address will be attached with the
      attributes encoded in "Address as Value" which follows this field.

   Address as Value:  this AFI encoded address will be the attribute
      address that goes along with "Address as Key" which precedes this
      field.

4.15.  Applications for AFI List Type

4.15.1.  Binding IPv4 and IPv6 Addresses

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

   Address Binding LISP Canonical Address Format:

     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 =3D 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Type =3D 1    |     Rsvd2     |         2 + 4 + 2 + 16        |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |            AFI =3D 1            |       IPv4 Address ...        |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |     ...  IPv4 Address         |            AFI =3D 2            |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                          IPv6 Address ...                     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     ...  IPv6 Address  ...                    |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     ...  IPv6 Address  ...                    |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     ...  IPv6 Address                         |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Length:  length in bytes is fixed at 24 when IPv4 and IPv6 AFI
      encoded addresses are used.

   This type of address format can be included in a Map-Request when the
   address is being used as an EID, but the 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.

4.15.2.  Layer-2 VPNs

   When MAC addresses are stored in the LISP Mapping Database System,
   the AFI List Type can be used to carry AFI 6.

   MAC Address LISP Canonical Address Format:

     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 =3D 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Type =3D 1    |     Rsvd2     |             2 + 6             |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |             AFI =3D 6           |    Layer-2 MAC Address  ...   |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                    ... Layer-2 MAC Address                    |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Length:  length in bytes is fixed at 8 when MAC address AFI encoded
      addresses are used.

   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 RLOCs, or
   even another MAC address being used as an RLOC.

4.15.3.  ASCII Names in the Mapping Database

   If DNS names or URIs are stored in the LISP Mapping Database System,
   the AFI List Type can be used to carry an ASCII string where it is
   delimited by length 'n' of the LCAF Length encoding.

   ASCII LISP Canonical Address Format:

     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 =3D 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Type =3D 1    |     Rsvd2     |             2 + n             |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |             AFI =3D 17          |      DNS Name or URI  ...     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Length value n:  length in bytes AFI=3D17 field and the =
null-terminated
      ASCII string (the last byte of 0 is included).

4.15.4.  Using Recursive LISP Canonical Address Encodings

   When any combination of above is desirable, the AFI List Type value
   can be used to carry within the LCAF AFI another LCAF AFI.

   Recursive LISP Canonical Address Format:

     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 =3D 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Type =3D 1    |     Rsvd2     |         4 + 8 + 2 + 4         |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |           AFI =3D 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Type =3D 4    |     Rsvd2     |              12               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   IP TOS, IPv6 QQS or Flow Label              |    Protocol   |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |           Local Port          |         Remote Port           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |            AFI =3D 1            |       IPv4 Address ...        |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |     ...  IPv4 Address         |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Length:  length in bytes is fixed at 18 when an AFI=3D1 IPv4 address =
is
      included.

   This format could be used by a Mapping Database Transport System,
   such as LISP-ALT [RFC6836], where the AFI=3D1 IPv4 address is used as
   an EID and placed in the Map-Request destination address by the
   sending LISP system.  The ALT system can deliver the Map-Request to
   the LISP destination site independent of the Application Data Type
   AFI payload values.  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.

4.15.5.  Compatibility Mode Use Case

   A LISP system should use the AFI List 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.

   Compatibility Mode Address Format:

     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 =3D 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Type =3D 1    |     Rsvd2     |            22 + 6             |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |           AFI =3D 16387         |     Rsvd1     |     Flags     |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |   Type =3D 5    |     Rsvd2     |            12 + 2             |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |N|     Latitude Degrees        |    Minutes    |    Seconds    |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |E|     Longitude Degrees       |    Minutes    |    Seconds    |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                            Altitude                           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              AFI =3D 0          |           AFI =3D 1             =
|
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                          IPv4 Address                         |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   If a system does not recognized the Geo Coordinate LCAF Type that is
   accompanying a locator address, an encoder can include the Geo
   Coordinate LCAF Type embedded in a AFI List LCAF Type where the AFI
   in the Geo Coordinate LCAF 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 bytes of the Geo Coordinate
   LCAF Type to get to the locator address encoding (an IPv4 locator
   address).  A LISP system that does support the Geo Coordinate LCAF
   Type can support parsing the locator address within the Geo
   Coordinate LCAF encoding or in the locator encoding that follows in
   the AFI List LCAF.

5.  Security Considerations

   There are no security considerations for this specification.  The
   security considerations are documented for the protocols that use
   LISP Canonical Addressing.  Refer to the those relevant
   specifications.

6.  IANA Considerations

   The Address Family AFI definitions from [AFI] 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.  Where the LISP protocol uses LISP Canonical Addresses
   specifically, the address length definitions will be in this
   specification and take precedent over any other specification.

   An IANA Registry for LCAF Type values will be created.  The values
   that are considered for use by the main LISP specification [RFC6830]
   will be in the IANA Registry.  Other Type values used for
   experimentation will be defined and described in this document.

7.  References

7.1.  Normative References

   [RFC1700]  Reynolds, J. and J. Postel, "Assigned Numbers", RFC 1700,
              October 1994.

   [RFC1918]  Rekhter, Y., Moskowitz, R., Karrenberg, D., Groot, G., and
              E. Lear, "Address Allocation for Private Internets",
              BCP 5, RFC 1918, February 1996.

   [RFC4627]  Crockford, D., "The application/json Media Type for
              JavaScript Object Notation (JSON)", RFC 4627, July 2006.

   [RFC6830]  Farinacci, D., Fuller, V., Meyer, D., and D. Lewis, "The
              Locator/ID Separation Protocol (LISP)", RFC 6830,
              January 2013.

   [RFC6836]  Fuller, V., Farinacci, D., Meyer, D., and D. Lewis,
              "Locator/ID Separation Protocol Alternative Logical
              Topology (LISP+ALT)", RFC 6836, January 2013.

7.2.  Informative References

   [AFI]      IANA, "Address Family Identifier (AFIs)", ADDRESS FAMILY
              NUMBERS http://www.iana.org/numbers.html, Febuary 2007.

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

   [LISP-DDT]
              Fuller, V., Lewis, D., and V. Ermagan, "LISP Delegated
              Database Tree", draft-ietf-lisp-ddt-01.txt (work in
              progress).

   [LISP-MRSIG]
              Farinacci, D. and M. Napierala, "LISP Control-Plane
              Multicast Signaling",
              draft-farinacci-lisp-mr-signaling-03.txt (work in
              progress).

   [LISP-NATT]
              Ermagan, V., Farinacci, D., Lewis, D., Skriver, J., Maino,
              F., and C. White, "NAT traversal for LISP",
              draft-ermagan-lisp-nat-traversal-03.txt (work in
              progress).

   [LISP-RE]  Coras, F., Cabellos-Aparicio, A., Domingo-Pascual, J.,
              Maino, F., and D. Farinacci, "LISP Replication
              Engineering", draft-coras-lisp-re-03.txt (work in
              progress).

   [LISP-TE]  Farinacci, D., Lahiri, P., and M. Kowal, "LISP Traffic
              Engineering Use-Cases", draft-farinacci-lisp-te-03.txt
              (work in progress).

   [WGS-84]   Geodesy and Geophysics Department, DoD., "World Geodetic
              System 1984", NIMA TR8350.2, January 2000, <http://
              earth-info.nga.mil/GandG/publications/tr8350.2/
              wgs84fin.pdf>.

Appendix A.  Acknowledgments

   The authors would like to thank Vince Fuller, Gregg Schudel, Jesper
   Skriver, Luigi Iannone, Isidor Kouvelas, and Sander Steffann for
   their technical and editorial commentary.

   The authors would like to thank Victor Moreno for discussions that
   lead to the definition of the Multicast Info LCAF type.

   The authors would like to thank Parantap Lahiri and Michael Kowal for
   discussions that lead to the definition of the Explicit Locator Path
   (ELP) LCAF type.

   The authors would like to thank Fabio Maino and Vina Ermagan for
   discussions that lead to the definition of the Security Key LCAF
   type.

   The authors would like to thank Albert Cabellos-Aparicio and Florin
   Coras for discussions that lead to the definition of the Replication
   List Entry LCAF type.

   Thanks goes to Michiel Blokzijl and Alberto Rodriguez-Natal for
   suggesting new LCAF types.

   Thanks also goes to Terry Manderson for assistance obtaining a LISP
   AFI value from IANA.

Appendix B.  Document Change Log

B.1.  Changes to draft-ietf-lisp-lcaf-05.txt=

   o  Submitted May 2014.

   o  Add a length field of the JSON payload that can be used for either
      binary or text encoding of JSON data.

B.2.  Changes to draft-ietf-lisp-lcaf-04.txt

   o  Submitted January 2014.

   o  Agreement among ELP implementors to have the AFI 16-bit field
      adjacent to the address.  This will make the encoding consistent
      with all other LCAF type address encodings.

B.2.

B.3.  Changes to =
draft-ietf-lisp-lcaf-03.txt

   o  Submitted September 2013.

   o  Updated references and author's affilations.

   o  Added Instance-ID to the Multicast Info Type so there is relative
      ease in parsing (S,G) entries within a VPN.

   o  Add port range encodings to the Application Data LCAF Type.

   o  Add a new JSON LCAF Type.

   o  Add Address Key/Value LCAF Type to allow attributes to be attached
      to an address.

B.3.

B.4.  Changes to =
draft-ietf-lisp-lcaf-02.txt

   o  Submitted March 2013.

   o  Added new LCAF Type "Replication List Entry" to support LISP
      replication engineering use-cases.

   o  Changed references to new LISP RFCs.

B.4.

B.5.  Changes to =
draft-ietf-lisp-lcaf-01.txt

   o  Submitted January 2013.

   o  Change longitude range from 0-90 to 0-180 in section 4.4.

   o  Added reference to WGS-84 in section 4.4.

B.5.

B.6.  Changes to =
draft-ietf-lisp-lcaf-00.txt

   o  Posted first working group draft August 2012.

   o  This draft was renamed from draft-farinacci-lisp-lcaf-10.txt.

Authors' Addresses

   Dino Farinacci
   lispers.net
   San Jose, CA
   USA

   Email: farinacci@gmail.com

   Dave Meyer
   Brocade
   San Jose, CA
   USA

   Email: dmm@1-4-5.net

   Job Snijders
   Hibernia Networks
   Tupolevlaan 103a
   Schiphol-Rijk,   1119 PA
   NL

   Email: job.snijders@hibernianetworks.com