RFC 8060
LISP Canonical Address Format (LCAF)
Internet Engineering Task Force (IETF) D. Farinacci Request for Comments: 8060 lispers.net Category: Experimental D. Meyer ISSN: 2070-1721 Brocade J. Snijders NTT February 2017 LISP Canonical Address Format (LCAF)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. Status of This Memo This document is not an Internet Standards Track specification; it is published for examination, experimental implementation, and evaluation. This document defines an Experimental Protocol for the Internet community. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Not all documents approved by the IESG are a candidate for any level of Internet Standard; see Section 2 of RFC 7841. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc8060.
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Table of Contents
1. Introduction ....................................................4 2. Terminology .....................................................5 2.1. Requirements Language ......................................5 2.2. Definition of Terms ........................................5 3. LISP Canonical Address Format Encodings .........................6 4. LISP Canonical Address Applications .............................8 4.1. Segmentation Using LISP ....................................8 4.2. Carrying AS Numbers in the Mapping Database ................9 4.3. Assigning Geo-Coordinates to Locator Addresses ............10 4.4. NAT Traversal Scenarios ...................................11 4.5. Multicast Group Membership Information ....................13 4.6. Traffic Engineering Using Re-encapsulating Tunnels ........15 4.7. Storing Security Data in the Mapping Database .............16 4.8. Source/Destination 2-Tuple Lookups ........................17 4.9. Replication List Entries for Multicast Forwarding .........18 4.10. Applications for AFI List LCAF Type ......................19 4.10.1. Binding IPv4 and IPv6 Addresses ...................19 4.10.2. Layer 2 VPNs ......................................20 4.10.3. ASCII Names in the Mapping Database ...............21 4.10.4. Using Recursive LISP Canonical Address Encodings ..22 4.10.5. Compatibility Mode Use Case .......................23 5. Experimental LISP Canonical Address Applications ...............24 5.1. Convey Application-Specific Data ..........................24 5.2. Generic Database Mapping Lookups ..........................25 5.3. PETR Admission Control Functionality ......................26 5.4. Data Model Encoding .......................................27 5.5. Encoding Key/Value Address Pairs ..........................28 5.6. Multiple Data-Planes ......................................29 6. Security Considerations ........................................31 7. IANA Considerations ............................................31 8. References .....................................................32 8.1. Normative References ......................................32 8.2. Informative References ....................................33 Acknowledgments ...................................................35 Authors' Addresses ................................................36
1. Introduction
The LISP architecture and protocol [RFC6830] introduces two new numbering spaces: 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. Currently defined AFIs include IPv4 and IPv6 addresses, which are formatted according to code-points assigned in the "Address Family Numbers" registry [AFN] 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 = 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 = 2 | IPv6 Address ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... IPv6 Address ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... IPv6 Address ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... IPv6 Address ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... IPv6 Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ This document describes the currently defined AFIs that LISP 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. Specific detailed uses for the LCAF Types defined in this document can be found in the use-case documents that implement them. The same LCAF Type may be used by more than one use-case document. As an Experimental specification, this work is, by definition, incomplete.
The LCAF Types defined in this document are to support experimentation and are intended for cautious use in self-contained environments in support of the corresponding use-case documents. This document provides assignment for an initial set of approved LCAF Types (registered with IANA) and additional unapproved LCAF Types [RFC6830]. The unapproved LCAF encodings are defined to support further study and experimentation.2. Terminology
2.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].2.2. Definition of Terms
Address Family Identifier (AFI): a term used to describe an address encoding in a packet. Address families are defined for IPv4 and IPv6. See [AFN] and [RFC3232] for details. The reserved AFI value of 0 is used in this specification to indicate an unspecified encoded address where 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 = 0 | <no address follows> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 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 an 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 Provider-Assigned (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 Canonical
Address Format (LCAF). This specification defines the encoding
format of the LISP Canonical Address (LCA). This section defines all
Types for which an initial allocation in the LISP-LCAF registry is
requested. See Section 7 for the complete list of such Types.
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. When
LISP uses LCAF definitions from this document, the AFI-based address
lengths are specified in this document. When new LCAF definitions
are defined in other use-case documents, the AFI-based address
lengths for any new AFI-encoded addresses are specified in those
documents.
The first 6 bytes of a LISP Canonical Address are followed by a
variable number of fields of variable length:
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| . . . |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Rsvd1/Rsvd2: these 8-bit fields are 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
Format encodings. Both approved and unapproved values are listed
below. Unapproved values are indicated; see Section 5 for more
details.
Type 0: Null Body Type 1: AFI List Type 2: Instance ID Type 3: AS Number Type 4: Application Data (unapproved; see Section 5) Type 5: Geo-Coordinates Type 6: Opaque Key (unapproved; see Section 5) Type 7: NAT-Traversal Type 8: Nonce Locator (unapproved; see Section 5) Type 9: Multicast Info Type 10: Explicit Locator Path Type 11: Security Key Type 12: Source/Dest Key Type 13: Replication List Entry Type 14: JSON Data Model (unapproved; see Section 5) Type 15: Key/Value Address Pair (unapproved; see Section 5) Type 16: Encapsulation Format (unapproved; see Section 5) 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. When including the AFI, an 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, Rsvd1, Rsvd2, and Length fields. When the AFI is not next to an encoded address in a control message, the encoded address will have a minimum length of 6 bytes when the Length field is 0. The 6 bytes include the Flags, Type, Rsvd1, Rsvd2, and Length fields.
[RFC6830] 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}. 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 Applications
The following sections define the LCAF for the currently approved initial set of Type values.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 = 16387 | Rsvd1 | Flags | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type = 2 | IID mask-len | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Instance ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | AFI = 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. The low-order bits of the Instance ID field must be 0. Length: length in bytes starting and including the byte after this Length field.
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
reason for the length difference is so that the maximum number of
instances supported per mapping system is 2^32, while conserving
space in the LISP data header. This comes at the expense of
limiting the maximum number of instances per xTR to 2^24. If an
xTR is configured with multiple Instance IDs where the value in
the high-order 8 bits is the same, then the low-order 24 bits MUST
be unique.
AFI = x: x can be any AFI value from [AFN].
This LISP Canonical Address Type can be used to encode either EID or
RLOC addresses.
Usage: When used as a lookup key, the EID is regarded as an extended-
EID in the mapping system. This encoding is used in EID-records in
Map-Request, Map-Reply, Map-Register, and Map-Notify messages. When
LISP Delegated Database Tree (LISP-DDT) [LISP-DDT] is used as the
mapping system mechanism, extended EIDs are used in Map-Referral
messages.
4.2. Carrying AS Numbers in the Mapping Database
When an Autonomous System (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 = 16387 | Rsvd1 | Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 3 | Rsvd2 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AS Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFI = x | Address ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Length: length in bytes starting and including the byte after this
Length field.
AS Number: the 32-bit AS number of the autonomous system that has
been assigned to either the EID or RLOC that follows.
AFI = x: x can be any AFI value from [AFN]. 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. Usage: This encoding can be used in EID-records or RLOC-records in Map-Request, Map-Reply, Map-Register, and Map-Notify messages. When LISP-DDT [LISP-DDT] is used as the mapping system mechanism, extended EIDs are used in Map-Referral messages.4.3. 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-Coordinates LCAF Type to convey physical location information. Coordinates are specified using the WGS 84 (World Geodetic System 1984) reference coordinate system [WGS-84]. Geo-Coordinates 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 = 16387 | Rsvd1 | Flags | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type = 5 | Rsvd2 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |N| Latitude Degrees | Minutes | Seconds | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |E| Longitude Degrees | Minutes | Seconds | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Altitude | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | AFI = x | Address ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Length: length in bytes starting and including the byte after this Length field. 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: Valid 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 two's
complement signed integer meaning that the altitude could be below
sea level. A value of 0x7fffffff indicates no Altitude value is
encoded.
AFI = x: x can be any AFI value from [AFN].
The Geo-Coordinates LCAF 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.
Usage: This encoding can be used in EID-records or RLOC-records in
Map-Request, Map-Reply, Map-Register, and Map-Notify messages. When
LISP-DDT [LISP-DDT] is used as the mapping system mechanism, extended
EIDs are used in Map-Referral messages.
The use of the Geo-Coordinates LCAF encoding raises privacy issues as
location information is privacy sensitive, and possibly unexpectedly
privacy-sensitive information may be conveyed, e.g., if the location
information corresponds to a router located in a person's home.
Therefore, this encoding should not be used unless needed for
operation of a LISP deployment. Before electing to utilize this
encoding, care should be taken to ensure the appropriate policies are
being used by the EID for controlling the conveyed information.
4.4. 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 [NAT-LISP] 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 = 16387 | Rsvd1 | Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 7 | Rsvd2 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MS UDP Port Number | ETR UDP Port Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFI = x | Global ETR RLOC Address ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFI = x | MS RLOC Address ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFI = x | Private ETR RLOC Address ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFI = x | RTR RLOC Address 1 ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFI = x | RTR RLOC Address k ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Length: length in bytes starting and including the byte after this
Length field.
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 that was copied from the source port from a packet that has
flowed through a NAT device.
AFI = x: x can be any AFI value from [AFN].
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 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
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 one or more NAT Re-encapsulating
Tunnel Router (RTR) [NAT-LISP] addresses supplied in these set of
fields. The number of RTRs encoded is determined by parsing each
field. When there are no RTRs supplied, the RTR fields can be
omitted and reflected by the LCAF length field or an AFI of 0 can
be used to indicate zero RTRs encoded.
Usage: This encoding can be used in Info-Request and Info-Reply
messages. The mapping system does not store this information. The
information is used by an xTR and Map-Server to convey private and
public address information when traversing NAT and firewall devices.
Care should be taken to protect privacy against the adverse use of a
Global or Private ETR RLOC Address by ensuring policy controls are
used during EID registrations that use this LCAF Type in RLOC-
records. Refer to the use-case documents for additional information.
4.5. Multicast Group Membership Information
Multicast group information can be published in the mapping database.
So a lookup on a group address EID can return a replication list of
RLOC group addresses or RLOC unicast addresses. 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 an EID is away from its 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 = 16387 | Rsvd1 | Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 9 | Rsvd2 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Instance ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Source MaskLen| Group MaskLen |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFI = x | Source/Subnet Address ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFI = x | Group Address ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Length: length in bytes starting and including the byte after this
Length field.
Reserved: must be set to zero and ignored on receipt.
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.
The length is the number of high-order mask bits set.
Group MaskLen: the mask length of the group prefix that follows.
The length is the number of high-order mask bits set.
AFI = x: x can be any AFI value from [AFN]. When a specific address
family has a multicast address semantic, this field must be either
a group address or a broadcast address.
Source/Subnet Address: the source address or prefix for encoding an
(S,G) multicast entry.
Group Address: the group address or group prefix for encoding (S,G)
or (*,G) multicast entries.
Usage: This encoding can be used in EID-records in Map-Request, Map- Reply, Map-Register, and Map-Notify messages. When LISP-DDT [LISP-DDT] is used as the mapping system mechanism, extended EIDs are used in Map-Referral messages.4.6. Traffic Engineering Using Re-encapsulating Tunnels
For a given EID lookup into the mapping database, this LCAF 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 = 16387 | Rsvd1 | Flags | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type = 10 | Rsvd2 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Rsvd3 |L|P|S| AFI = x | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reencap Hop 1 ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Rsvd3 |L|P|S| AFI = x | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reencap Hop k ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Length: length in bytes starting and including the byte after this Length field. Rsvd3: this field is reserved for future use and MUST be transmitted as 0 and ignored on receipt. Lookup bit (L): this is the Lookup bit used to indicate to the user of the ELP not to 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 that 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 be reachable.
Strict bit (S): this is the Strict bit, which means the associated
Reencap Hop is required to be used. If this bit is 0, the
re-encapsulator can skip this Reencap Hop and go to the next one
in the list.
AFI = x: x can be any AFI value from [AFN]. When a specific AFI has
its own encoding of a multicast address, this field must be either
a group address or a broadcast address.
Usage: This encoding can be used in RLOC-records in Map-Request, Map-
Reply, Map-Register, and Map-Notify messages. This encoding does not
need to be understood by the mapping system for mapping database
lookups, since this LCAF Type is not a lookup key.
4.7. Storing Security Data in the Mapping Database
When a locator in a locator-set has a security key associated with
it, this LCAF 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 = 16387 | Rsvd1 | Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 11 | Rsvd2 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Key Count | Rsvd3 | Key Algorithm | Rsvd4 |R|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Key Length | Key Material ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... Key Material |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFI = x | Locator Address ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Length: length in bytes starting and including the byte after this
Length field.
Key Count: the Key Count field declares the number of Key sections
included in this LCAF. A Key section is made up of Key Length and
Key Material fields.
Rsvd3: this field is reserved for future use and MUST be transmitted
as 0 and ignored on receipt.
Key Algorithm: the Key Algorithm field identifies the key's
cryptographic algorithm and specifies the format of the Public Key
field. Refer to the [LISP-DDT] and [RFC8061] use cases for
definitions of this field.
Rsvd4: this field is reserved for future use and MUST be transmitted
as 0 and ignored on receipt.
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 = x: x can be any AFI value from [AFN]. This is the locator
address that owns the encoded security key.
Usage: This encoding can be used in EID-records or RLOC-records in
Map-Request, Map-Reply, Map-Register, and Map-Notify messages. When
LISP-DDT [LISP-DDT] is used as the mapping system mechanism, extended
EIDs are used in Map-Referral messages.
4.8. Source/Destination 2-Tuple Lookups
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.
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 = 16387 | Rsvd1 | Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 12 | Rsvd2 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Source-ML | Dest-ML |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFI = x | Source-Prefix ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFI = y | Destination-Prefix ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Length: length in bytes starting and including the byte after this
Length field.
Reserved: must be set to zero 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 = x: x can be any AFI value from [AFN].
AFI = y: y can be any AFI value from [AFN]. When a specific address
family has a multicast address semantic, this field must be either
a group address or a broadcast address.
Usage: This encoding can be used in EID-records in Map-Request, Map-
Reply, Map-Register, and Map-Notify messages. When LISP-DDT
[LISP-DDT] is used as the mapping system mechanism, extended EIDs are
used in Map-Referral messages. Refer to [LISP-TE] for usage details
of this LCAF Type.
4.9. 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 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 = 16387 | Rsvd1 | Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 13 | Rsvd2 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Rsvd3 | Rsvd4 | Level Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFI = x | RTR/ETR #1 ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Rsvd3 | Rsvd4 | Level Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFI = x | RTR/ETR #n ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Length: length in bytes starting and including the byte after this
Length field.
Rsvd3/Rsvd4: must be set to zero and ignored 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 = x: x can be any AFI value from [AFN]. A specific AFI has its
own encoding of either a unicast or multicast locator address.
For efficiency reasons, all RTR/ETR entries for the same level
should be combined by a Map-Server to avoid searching through the
entire multilevel list of locator entries in a Map-Reply message.
Usage: This encoding can be used in RLOC-records in Map-Request, Map-
Reply, Map-Register, and Map-Notify messages.
(page 19 continued on part 2)
