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diff --git a/doc/rfc/rfc6741.txt b/doc/rfc/rfc6741.txt new file mode 100644 index 0000000..1c75a2a --- /dev/null +++ b/doc/rfc/rfc6741.txt @@ -0,0 +1,2131 @@ + + + + + + +Internet Research Task Force (IRTF) RJ Atkinson +Request for Comments: 6741 Consultant +Category: Experimental SN Bhatti +ISSN: 2070-1721 U. St Andrews + November 2012 + + + Identifier-Locator Network Protocol (ILNP) + Engineering Considerations + +Abstract + + This document describes common (i.e., version independent) + engineering details for the Identifier-Locator Network Protocol + (ILNP), which is an experimental, evolutionary enhancement to IP. + This document is a product of the IRTF Routing Research Group. + +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 Research Task + Force (IRTF). The IRTF publishes the results of Internet-related + research and development activities. These results might not be + suitable for deployment. This RFC represents the individual + opinion(s) of one or more members of the Routing Research Group of + the Internet Research Task Force (IRTF). Documents approved for + publication by the IRSG are not a candidate for any level of Internet + Standard; see Section 2 of RFC 5741. + + 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/rfc6741. + + + + + + + + + + + + + + + +Atkinson & Bhatti Experimental [Page 1] + +RFC 6741 ILNP Engineering November 2012 + + +Copyright Notice + + Copyright (c) 2012 IETF Trust and the persons identified as the + document authors. All rights reserved. + + This document is subject to BCP 78 and the IETF Trust's Legal + Provisions Relating to IETF Documents + (http://trustee.ietf.org/license-info) in effect on the date of + publication of this document. Please review these documents + carefully, as they describe your rights and restrictions with respect + to this document. + + This document may not be modified, and derivative works of it may not + be created, except to format it for publication as an RFC or to + translate it into languages other than English. + +Table of Contents + + 1. Introduction ....................................................3 + 1.1. Document Roadmap ...........................................4 + 1.2. Terminology ................................................5 + 2. ILNP Identifiers ................................................5 + 2.1. Syntax .....................................................6 + 2.2. Default Values for an Identifier ...........................6 + 2.3. Local-Scoped Identifier Values .............................6 + 2.4. Multicast Identifiers ......................................7 + 2.5. Administration of Identifier Values ........................7 + 3. Encoding of Identifiers and Locators for ILNPv6 .................7 + 3.1. Encoding of I and L Values .................................7 + 3.2. Network-Level Packet Formats ..............................10 + 3.3. Encoding of Identifiers and Locators for ILNPv4 ...........11 + 4. Transport-Layer Changes ........................................12 + 4.1. End-System State ..........................................12 + 4.2. TCP/UDP Checksum Handling .................................12 + 4.3. ICMP Checksum Handling ....................................12 + 5. ILNP Communication Cache (ILCC) ................................13 + 5.1. Formal Definition .........................................13 + 5.2. Ageing ILCC Entries .......................................15 + 5.3. Large Numbers of Locators .................................15 + 5.4. Lookups into the ILCC .....................................16 + 6. Handling Location/Connectivity Changes .........................16 + 6.1. Node Location/Connectivity Changes ........................16 + 6.2. Network Connectivity/Locator Changes ......................17 + 7. Subnetting .....................................................17 + 7.1. Subnetting for ILNPv6 .....................................18 + 7.2. Subnetting for ILNPv4 .....................................19 + 7.3. Subnetting for Router-Router Links in IPv6/ILNPv6 .........19 + 8. DNS Considerations .............................................19 + + + +Atkinson & Bhatti Experimental [Page 2] + +RFC 6741 ILNP Engineering November 2012 + + + 8.1. Secure Dynamic DNS Update .................................19 + 8.2. New DNS RR Types ..........................................20 + 8.4. DNS TTL Values for ILNP RRS Types .........................21 + 8.5. IP/ILNP Dual Operation and Transition .....................21 + 9. IP Security for ILNP ...........................................22 + 9.1. IPsec Security Association Enhancements for ILNP ..........22 + 9.2. IP Authentication Header Enhancements for ILNP ............23 + 9.3. Key Management Considerations .............................23 + 10. Backwards Compatibility and Incremental Deployment ............24 + 10.1. Priorities in the Design of ILNPv6 and ILNPv4 ............24 + 10.2. Infrastructure ...........................................25 + 10.3. Core Protocols ...........................................25 + 10.4. Scope of End-System Changes ..............................26 + 10.5. Applications .............................................27 + 10.6. Interworking between IP and ILNP .........................27 + 11. Security Considerations .......................................28 + 11.1. Authenticating ICMP Messages .............................29 + 11.2. Forged Identifier Attacks ................................31 + 12. Privacy Considerations ........................................31 + 13. Operational Considerations ....................................31 + 13.1. Session Liveness and Reachability ........................32 + 13.2. Key Management Considerations ............................33 + 13.3. Point-to-Point Router Links ..............................33 + 14. Referrals and Application Programming Interfaces ..............34 + 14.1. BSD Sockets APIs .........................................34 + 14.2. Java (and Other) APIs ....................................34 + 14.3. Referrals in the Future ..................................35 + 15. References ....................................................35 + 15.1. Normative References .....................................35 + 15.2. Informative References ...................................36 + 16. Acknowledgements ..............................................38 + +1. Introduction + + The ILNP document set has had extensive review within the IRTF + Routing RG. ILNP is one of the recommendations made by the RG + Chairs. Separately, various refereed research papers on ILNP have + also been published during this decade. So, the ideas contained + herein have had much broader review than IRTF Routing RG. The views + in this document were considered controversial by the Routing RG, but + the RG reached a consensus that the document still should be + published. The Routing RG has had remarkably little consensus on + anything, so virtually all Routing RG outputs are considered + controversial. + + At present, the Internet research and development community is + exploring various approaches to evolving the Internet Architecture to + solve a variety of issues including, but not limited to, scalability + + + +Atkinson & Bhatti Experimental [Page 3] + +RFC 6741 ILNP Engineering November 2012 + + + of inter-domain routing [RFC4984]. A wide range of other issues + (e.g., site multihoming, node multihoming, site/subnet mobility, node + mobility) are also active concerns at present. Several different + classes of evolution are being considered by the Internet research + and development community. One class is often called "Map and + Encapsulate", where traffic would be mapped and then tunnelled + through the inter-domain core of the Internet. Another class being + considered is sometimes known as "Identifier/Locator Split". This + document relates to a proposal that is in the latter class of + evolutionary approaches. + + The Identifier-Locator Network Protocol (ILNP) is an experimental + network protocol that provides evolutionary enhancements to IP. ILNP + is backwards compatible with IP and is incrementally deployable. The + best starting point for learning about ILNP is the ILNP Architectural + Description, which includes a document roadmap [RFC6740]. + +1.1. Document Roadmap + + This document describes engineering and implementation considerations + that are common to both ILNP for IPv4 (ILNPv4) and ILNP for IPv6 + (ILNPv6). + + The ILNP architecture can have more than one engineering + instantiation. For example, one can imagine a "clean-slate" + engineering design based on the ILNP architecture. In separate + documents, we describe two specific engineering instances of ILNP. + The term "ILNPv6" refers precisely to an instance of ILNP that is + based upon, and backwards compatible with, IPv6. The term "ILNPv4" + refers precisely to an instance of ILNP that is based upon, and + backwards compatible with, IPv4. + + Many engineering aspects common to both ILNPv4 and ILNPv6 are + described in this document. A full engineering specification for + either ILNPv6 or ILNPv4 is beyond the scope of this document. + + Readers are referred to other related ILNP documents for details not + described here: + + a) [RFC6740] is the main architectural description of ILNP, including + the concept of operations. + + b) [RFC6742] defines additional DNS resource records that support + ILNP. + + c) [RFC6743] defines a new ICMPv6 Locator Update message used by an + ILNP node to inform its correspondent nodes of any changes to its + set of valid Locators. + + + +Atkinson & Bhatti Experimental [Page 4] + +RFC 6741 ILNP Engineering November 2012 + + + d) [RFC6744] defines a new IPv6 Nonce Destination Option used by + ILNPv6 nodes (1) to indicate to ILNP correspondent nodes (by + inclusion within the initial packets of an ILNP session) that the + node is operating in the ILNP mode and (2) to prevent off-path + attacks against ILNP ICMP messages. This Nonce is used, for + example, with all ILNP ICMPv6 Locator Update messages that are + exchanged among ILNP correspondent nodes. + + e) [RFC6745] defines a new ICMPv4 Locator Update message used by an + ILNP node to inform its correspondent nodes of any changes to its + set of valid Locators. + + f) [RFC6746] defines a new IPv4 Nonce Option used by ILNPv4 nodes to + carry a security nonce to prevent off-path attacks against ILNP + ICMP messages and also defines a new IPv4 Identifier Option used + by ILNPv4 nodes. + + g) [RFC6747] describes extensions to Address Resolution Protocol + (ARP) for use with ILNPv4. + + h) [RFC6748] describes optional engineering and deployment functions + for ILNP. These are not required for the operation or use of ILNP + and are provided as additional options. + +1.2. Terminology + + 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]. + + Several technical terms (e.g., "ILNP session") that are used by this + document are defined in [RFC6740]. It is strongly recommended that + one read [RFC6740] before reading this document. + +2. ILNP Identifiers + + All ILNP nodes must have at least one Node Identifier (or just + "Identifier") value. However, there are various options for + generating those Identifier values. We describe, in this section, + the relevant engineering issues related to Identifier generation and + usage. + + Note well that an ILNP Node Identifier names an ILNP-capable node, + and it is NOT bound to a specific interface of that node. So a given + ILNP Node Identifier is valid on all active interfaces of the node to + which that ILNP Identifier is bound. This is true even if the bits + used to form the Identifier value happened to be taken from a + specific interface as an engineering convenience. + + + +Atkinson & Bhatti Experimental [Page 5] + +RFC 6741 ILNP Engineering November 2012 + + +2.1. Syntax + + ILNP Identifiers are always unsigned 64-bit strings, and they may be + realised as 64-bit unsigned integers. Both ILNPv4 and ILNPv6 use the + Modified EUI-64 [IEEE-EUI] syntax that is used by IPv6 interface + identifiers [RFC4291], Section 2.5.1, as shown in Figure 2.1. + + +--------------------------------------------------+ + | 6 id bits | U bit | G bit | 24 id bits | + +--------------------------------------------------+ + | 32 id bits | + +--------------------------------------------------+ + + Figure 2.1: Node Identifier Format as Used for IPv6, Using the + Same Syntax as in RFC 4291, Section 2.5.1. + + That syntax contains two special reserved bit flags. One flag (the U + bit) indicates whether the value has "universal" (i.e., global) scope + (1) or "local" (0) scope. The other flag (the G bit) indicates + whether the value is an "individual" address (1) or "group" (i.e., + multicast) (0) address. + + However, this format does allow other values to be set, by use of + administrative or other policy control, as required, by setting the U + bit to "local". + +2.2. Default Values for an Identifier + + By default, this value, including the U bit and G bit, are set as + described in Section 2.5.1 of [RFC4291]. Where no other value of + Identifier is available for an ILNP node, this is the value that MUST + be used. + + Because ILNP Identifiers might have local scope, and also to handle + the case where two nodes at different locations happen to be using + the same global scope Identifier (e.g., due to a manufacturing fault + in a network chipset or card), implementers must be careful in how + ILNP Identifiers are handled within an end system's networking + implementation. Some details are discussed in Section 4 below. + +2.3. Local-Scoped Identifier Values + + ILNP Identifiers for a node also MAY have the Scope bit of the Node + Identifier set to "local" scope. Locally unique identifiers MAY be + Cryptographically Generated, created following the procedures used + for IPv6 Cryptographically Generated Addresses (CGAs) [RFC3972] + [RFC4581] [RFC4982]. + + + + +Atkinson & Bhatti Experimental [Page 6] + +RFC 6741 ILNP Engineering November 2012 + + + Also, locally unique identifiers MAY be used to create the ILNP + equivalent to the Privacy Extensions for IPv6, generating ILNP + Identifiers following the procedures used for IPv6 [RFC4941]. + +2.4. Multicast Identifiers + + An ILNP Identifier with the G bit set to "group" names an ILNP + multicast group, while an ILNP Identifier with the G bit set to + "individual" names an individual ILNP node. However, this usage of + multicast for Identifiers for ILNP is currently undefined: ILNP uses + IPv6 multicast for ILNPv6 and IPv4 multicast for ILNPv4 and uses the + multicast address formats defined as appropriate. + + The use of multicast Identifiers and design of an enhanced multicast + capability for ILNPv6 and ILNPv4 is currently work in progress. + +2.5. Administration of Identifier Values + + Note that just as IPv6 does not need global, centralised + administrative management of its interface identifiers, so ILNPv6 + does not need global, centralised administrative management of the + Node Identifier (NID) values. + +3. Encoding of Identifiers and Locators for ILNPv6 + +3.1. Encoding of I and L Values + + With ILNPv6, the Identifier and Locator values within a packet are + encoded in the existing space for the IPv6 address. In general, the + ILNPv6 Locator has the same syntax and semantics as the current IPv6 + unicast routing prefix, as shown in Figure 3.1: + + /* IPv6 */ + | 64 bits | 64 bits | + +-------------------------------------+-------------------------+ + | IPv6 Unicast Routing Prefix | Interface Identifier | + +-------------------------------------+-------------------------+ + + /* ILNPv6 */ + | 64 bits | 64 bits | + +-------------------------------------+-------------------------+ + | Locator | Node Identifier (NID) | + +-------------------------------------+-------------------------+ + + Figure 3.1: The General Format of Encoding of I/NID and L Values + for ILNPv6 into the IPv6 Address Bits + + + + + +Atkinson & Bhatti Experimental [Page 7] + +RFC 6741 ILNP Engineering November 2012 + + + The syntactical structure of the IPv6 address spaces remains as given + in Section 2.5.4 of [RFC4291], and an example is shown in Figure 3.2, + which is based in part on [RFC3177] (which has since been obsoleted + by [RFC6177]). + + /* IPv6 */ + | 3 | 45 bits | 16 bits | 64 bits | + +---+---------------------+-----------+-------------------------+ + |001|global routing prefix| subnet ID | Interface Identifier | + +---+---------------------+-----------+-------------------------+ + + /* ILNPv6 */ + | 64 bits | 64 bits | + +---+---------------------+-----------+-------------------------+ + | Locator (L64) | Node Identifier (NID) | + +---+---------------------+-----------+-------------------------+ + + Figure 3.2: Example of IPv6 Address Format as Used in ILNPv6 + + The global routing prefix bits and subnet ID bits above are as for + [RFC3177], but could be different, e.g., as for [RFC6177]. + + The ILNPv6 Locator uses the upper 64-bits of the 128-bit IPv6 address + space. It has the same syntax and semantics as today's IPv6 routing + prefix. So, an ILNPv6 packet carrying a Locator value can be used + just like an IPv6 packet today as far as core routers are concerned. + + The example in Figure 3.2 happens to use a /48 prefix, as was + recommended by [RFC3177]. However, more recent advice is that + prefixes need not be fixed at /48 and could be up to /64 [RFC6177]. + This change, however, does not impact the syntax or semantics of the + Locator value. + + The ILNPv6 Identifier value uses the lower 64-bits of the 128-bit + IPv6 address. It has the same syntax as an IPv6 identifier, but + different semantics. This provides a fixed-length non-topological + name for a node. Identifiers are bound to nodes, not to interfaces + of a node. All ILNP Identifiers MUST comply with the modified EUI-64 + syntax already specified for IPv6's "interface identifier" values, as + described in Section 2.1. + + IEEE EUI-64 Identifiers can have either global-scope or local-scope. + So ILNP Identifiers also can have either global-scope or local-scope. + A reserved bit in the modified EUI-64 syntax clearly indicates + whether a given Identifier has global-scope or local-scope. A node + is not required to use a global-scope Identifier, although that is + the recommended practice. Note that the syntax of the Node + + + + +Atkinson & Bhatti Experimental [Page 8] + +RFC 6741 ILNP Engineering November 2012 + + + Identifier field has exactly the same syntax as that defined for IPv6 + address in Section 2.5.1 of [RFC4291]. (This is based on the IEEE + EUI-64 syntax [IEEE-EUI], but is not the same.) + + Most commonly, Identifiers have global-scope and are derived from one + or more IEEE 802 or IEEE 1394 'MAC Addresses' (sic) already + associated with the node, following the procedure already defined for + IPv6 [RFC4291]. Global-scope identifiers have a high probability of + being globally unique. This approach eliminates the need to manage + Identifiers, among other benefits. + + Local-scope Identifiers MUST be unique within the context of their + Locators. The existing mechanisms of the IPv4 Address Resolution + Protocol [RFC826] and IPv6 Stateless Address Autoconfiguration + (SLAAC) [RFC4862] automatically enforce this constraint. + + For example, on an Ethernet-based IPv4 subnetwork the ARP Reply + message is sent via link-layer broadcast, thereby advertising the + current binding between an IPv4 address and a Media Access Control + (MAC) address to all nodes on that IPv4 subnetwork. (Note also that + a well-known, long standing, issue with ARP is that it cannot be + authenticated.) Local-scope Identifiers MUST NOT be used with other + Locators without first ensuring uniqueness in the context of those + other Locators e.g., by using IPv6 Neighbour Discovery's Duplicate + Address Detection mechanism when using ILNPv6 or by sending an ARP + Request when using ILNPv4. + + Other methods might be used to generate local-scope Identifiers. For + example, one might derive Identifiers using some form of + cryptographic generation or using the methods specified in the IPv6 + Privacy Extensions [RFC4941] to Stateless Address Autoconfiguration + (SLAAC) [RFC4862]. When cryptographic generation of Identifiers + using methods described in RFC 3972 is in use, only the Identifier is + included, never the Locator, thereby preserving roaming capability. + One could also imagine creating a local-scope Identifier by taking a + cryptographic hash of a node's public key. Of course, in the + unlikely event of an Identifier collision, for example, when a node + has chosen to use a local-scope Identifier value, the node remains + free to use some other local-scope Identifier value(s). + + It is worth remembering here that an IPv6 address names a specific + network interface on a specific node, but an ILNPv6 Identifier names + the node itself, not a specific interface on the node. This + difference in definition is essential to providing seamless support + for mobility and multihoming, which are discussed in more detail + later in this note. + + + + + +Atkinson & Bhatti Experimental [Page 9] + +RFC 6741 ILNP Engineering November 2012 + + +3.2. Network-Level Packet Formats + + ILNPv6 Locator and Identifier values are encoded into IPv6 address + space and ILNPv6 uses directly the Classic IPv6 packet format, as + shown in Figure 3.3. This is also the view of an ILNPv6 packet as + seen by core routers -- they simply use the Locator value (top + 64-bits of the address field) just as they would use an IPv6 prefix + today (e.g., either as /48 or as /64 when using sub-network routing). + + 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 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + |Version| Traffic Class | Flow Label | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Payload Length | Next Header | Hop Limit | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Source Address | + + + + | | + + + + | | + + + + | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Destination Address | + + + + | | + + + + | | + + + + | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + Figure 3.3: Existing ("Classic") IPv6 Header + + In essence, the Locator names a subnetwork. (Locators can also be + referred to as Routing Prefixes if discussing Classic IPv6). Of + course, backwards compatibility requirements mean that ILNPv6 + Locators use the same number space as IPv6 routing prefixes. This + ensures that no changes are needed to deployed IPv6 routers when + deploying ILNPv6. + + The low-order 64-bits of the IPv6 address become the Identifier. + Details of the Identifier were discussed above. The Identifier is + only used by end-systems, so Figure 3.4 shows the view of the same + packet format, but as viewed by an ILNPv6 node. As this only needs + to be parsed in this way by the end-system, so ILNPv6 deployment is + enabled incrementally by updating end-systems as required. + + + +Atkinson & Bhatti Experimental [Page 10] + +RFC 6741 ILNP Engineering November 2012 + + + 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 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + |Version| Traffic Class | Flow Label | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Payload Length | Next Header | Hop Limit | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Source Locator | + + + + | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Source Identifier | + | | + + + + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Destination Locator | + + + + | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Destination Identifier | + + + + | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + + Figure 3.4: ILNPv6 Header as Seen by ILNPv6-Enabled End-Systems + +3.3. Encoding of Identifiers and Locators for ILNPv4 + + Encoding of Identifier and Locator values for ILNPv4 is not as + straightforward as for ILNPv6. In analogy to ILNPv6, in ILNPv4, the + Locator value is a routing prefix for IPv4, but is at most 30 bits. + Source Locator values are carried in the source address field of the + IPv4 header, and destination Locator values in the destination + address field. So, just like for ILNPv6, for ILNPv4, packet routing + can be performed by routers examining existing prefix values in the + IPv4 header. + + However, for ILNPv4, additional option headers have to be used to + carry the Identifier value as there is not enough room in the normal + IPv4 header fields. A 64-bit Identifier value is carried in an + option header. So, the detailed explanation of the ILNPv4 packet + header is to be found in [RFC6746]. + + + + + + + + + +Atkinson & Bhatti Experimental [Page 11] + +RFC 6741 ILNP Engineering November 2012 + + +4. Transport-Layer Changes + + ILNP uses an Identifier value in order to form the invariant end- + system state for end-to-end protocols. Currently, transport + protocols such as TCP and UDP use all the bits of an IP Address to + form such state. So, transport protocol implementations MUST be + modified in order to operate over ILNP. + +4.1. End-System State + + Currently, TCP and UDP, for example, use the 4-tuple: + + <local port, remote port, local IP Address, remote IP Address> + + for the end-system state for a transport layer end-point. For ILNP, + implementations must be modified to instead use the following: + + <local port, remote port, local Identifier, remote Identifier> + +4.2. TCP/UDP Checksum Handling + + In IP-based implementations, the TCP or UDP pseudo-header checksum + calculations include all the bits of the IP Address. By contrast, + when calculating the TCP or UDP pseudo-header checksums for use with + ILNP, only the Identifier values are included in the TCP or UDP + pseudo-header checksum calculations. + + To minimise the changes required within transport protocol + implementations, and to maximise interoperability, current + implementations are modified to zero the Locator fields (only for the + purpose of TCP or UDP checksum calculations). For example, for + ILNPv6, this means that the existing code for IPv6 can be used, with + the ILNPv6 Identifier bits occupying the lower 64 bits of the IPv6 + address field, and the upper 64 bits of the IPv6 address filed being + set to zero. For ILNPv4, the Identifier fields are carried in an + IPv4 Option [RFC6746]. + + Section 7 describes methods for incremental deployment of this ILNP- + specific change and backwards compatibility with non-upgraded nodes + (e.g., classic IPv4 or IPv6 nodes) in more detail. + +4.3. ICMP Checksum Handling + + To maximise backwards compatibility, the ILNPv6 ICMP checksum is + always calculated in the same way as for IPv6 ICMP. Similarly, the + ILNPv4 ICMP checksum is always calculated in the same way as for IPv4 + ICMP. + + + + +Atkinson & Bhatti Experimental [Page 12] + +RFC 6741 ILNP Engineering November 2012 + + +5. ILNP Communication Cache (ILCC) + + For operational purposes, implementations need to have a local cache + of state information that allow communication endpoints to be + constructed and for communication protocols to operate. Such cache + information is common today, e.g., IPv4 nodes commonly maintain an + Address Resolution Protocol (ARP) cache with information relating to + current and recent Correspondent Nodes (CNs); IPv6 nodes maintain a + Neighbor Discovery (ND) table with information relating to current + and CNs. Likewise, ILNP maintains an Identifier Locator + Communication Cache (ILCC) with information relating to the operation + of ILNP. + + The ILCC is a (logical) set of data values required for ILNP to + operate. These values are maintained by the endpoints of each ILNP + session. + + In theory, this cache is within the ILNP network-layer. However, + many network protocol implementations do not have strict protocol + separation or layering. So there is no requirement that the ILCC be + kept partitioned from transport-layer protocols. + + Note that, in many implementations, much of the information required + for the ILCC may already be present. Where some additional + information is required for ILNP, from an engineering viewpoint, the + ILCC could be implemented by extending or enhancing existing data + structures within existing implementations. For example, by adding + appropriate flags to the data structures in existing implementations. + + Note that the ILCC does not impose any extra state maintenance + requirements for applications or applications servers. For example, + in the case of, say, HTTP, there will be no additional state for a + server to maintain, and any TCP state will be handled by the ILNP + code in the OS just as for IP. + +5.1. Formal Definition + + The ILCC contains information about both the local node and also + about current or recent correspondent nodes, as follows. + + Information about the local node: + + - Each currently valid Identifier value, including its Identifier + Precedence and whether it is active at present. + + - Each currently valid Locator value, including its associated + local interface(s), its Locator Precedence and whether it is + active at present. + + + +Atkinson & Bhatti Experimental [Page 13] + +RFC 6741 ILNP Engineering November 2012 + + + - Each currently valid IL Vector (I-LV), including whether it is + active at present. + + Information about each correspondent node: + + - Most recent set of Identifiers, including lifetime and validity + for each. + + - Most recent set of Locators, including lifetime and validity for + each. + + - Nonce value for packets from the local host to the + correspondent. + + - Nonce value for packets from the correspondent to the local + host. + + In the above list for the ILNP Communication Cache: + + - A "valid" item is usable, from an administrative point of view, + but it might or might not be in use at present. + + - The "validity" parameter for the correspondent node indicates + one of several different states for a datum. These include at + least the following: + + - "valid": data is usable and has not expired. + + - "active": data is usable, has not expired, and is in active + use at present. + + - "expired": data is still in use at present, but is beyond its + expiration (i.e., without a replacement value). + + - "aged": data was recently in use, but is not in active use at + present, and is beyond its expiration. + + - The "lifetime" parameter is an implementation-specific + representation of the validity lifetime for the associated data + element. In normal operation, the Lifetime for a correspondent + node's Locator(s) are learned from the DNS Time-To-Live (DNS + TTL) value associated with DNS records (NID, L32, L64, etc.) of + the Fully Qualified Domain Name (FQDN) owner name of the + correspondent node. For time, a node might use UTC (e.g., via + Network Time Protocol) or perhaps some node-specific time (e.g., + seconds since node boot). + + + + + +Atkinson & Bhatti Experimental [Page 14] + +RFC 6741 ILNP Engineering November 2012 + + +5.2. Ageing ILCC Entries + + As a practical engineering matter, it is not sensible to flush all + Locator values associated with an existing ILNP session's + correspondent node even if the DNS TTL associated with those Locator + values expires. + + In some situations, a CN might be disconnected briefly when moving + location (e.g., immediate handover, which sometimes is called "break + before make"). If this happens, there might be a brief pause before + the Correspondent Node can (a) update its own L values in the DNS, + and (b) send an ICMP Locator Update message to the local node with + information about its new location. Implementers ought to try to + maintain ILNP sessions even when such events occur. + + Instead, Locator values cached for a correspondent node SHOULD be + marked as "aged" when their TTL has expired, but retained until + either the next Locator Update message is received, there is other + indication that a given Locator is not working any longer, there is + positive indication that the Correspondent Node has terminated the + ILNP session (e.g., TCP RST if the only transport-layer session for + this ILNP session is a TCP session), until some appropriate timeout + (e.g., 2*MSL for TCP if the only transport-layer session for this + ILNP session is a TCP session), or the ILNP session has been inactive + for several minutes (e.g., no transport-layer session exists for this + ILNP session) and the storage space associated with the aged entry + needs to be reclaimed. + + Separately, received authenticated Locator Update messages cause the + ILCC entries listed above to be updated. + + Similarly, if there is indication that an ILNP session with a + Correspondent Node remains active and the DNS TTL associated with + that Correspondent Node's active Identifier value(s) has expired, + those remote Identifier value(s) ought to be marked as "expired", but + retained since they are in active use. + +5.3. Large Numbers of Locators + + Implementers should keep in mind that a node or site might have a + large number of concurrent Locators, and it should ensure that a + system fault does not arise if the system receives an authentic ICMP + Locator Update containing a large number of Locator values. + + + + + + + + +Atkinson & Bhatti Experimental [Page 15] + +RFC 6741 ILNP Engineering November 2012 + + +5.4. Lookups into the ILCC + + For received packets containing an ILNP Nonce Option, lookups in the + ILCC MUST use the <remote Identifier, Nonce> tuple as the lookup key. + + For all other ILNP packets, lookups in the ILNP Correspondent Cache + MUST use the <remote Locator, remote Identifier> tuple, i.e., the + remote I-LV, as the lookup key. + + These two checks between them facilitate situations where, perhaps + due to deployment of Local-scope Identifiers, more than one + correspondent node is using the same Identifier value. + + (NOTE: Other mechanisms, such as IPv6 Neighbor Discovery, ensure that + two different nodes are incapable of using a given I-LV at the same + location, i.e., on the same link.) + + While Locators are omitted from the transport-layer checksum, an + implementation SHOULD use Locator values to distinguish between + correspondents coincidentally using the same Identifier value (e.g., + due to deployment of Local-scope Identifier values) when + demultiplexing to determine which application(s) should receive the + user data delivered by the transport-layer protocol. + +6. Handling Location/Connectivity Changes + + In normal operation, an ILNP node uses the DNS for initial rendezvous + in setting up ILNP sessions. The use of DNS for initial rendezvous + with mobile nodes was earlier proposed by others [PHG02] and then + separately reinvented by the current authors later on. + +6.1. Node Location/Connectivity Changes + + To handle the move of a node or a change to the upstream connectivity + of a multihomed node, we add a new ICMP control message [RFC6745] + [RFC6743]. The ICMP Locator Update (LU) message is used by a node to + inform its existing CNs that the set of valid Locators for the node + has changed. This mechanism can be used to add newly valid Locators, + to remove no longer valid Locators, or to do both at the same time. + The LU mechanism is analogous to the Binding Update mechanism in + Mobile IPv6, but in ILNP, such messages are used any time Locator + value changes need to be notified to CNs, e.g., for multihomed hosts + as well as for mobile hosts. + + Further, if the node wishes to be able to receive new incoming ILNP + sessions, the node normally uses Secure Dynamic DNS Update [RFC3007] + to ensure that a correct set of Locator values are present in the + + + + +Atkinson & Bhatti Experimental [Page 16] + +RFC 6741 ILNP Engineering November 2012 + + + appropriate DNS records (i.e., L32, L64) in the DNS for that node + [RFC6742]. This enables any new correspondents to correctly initiate + a new ILNP session with the node at its new location. + + While the Locator Update control message could be an entirely new + protocol running over UDP, for example, there is no obvious advantage + to creating a new protocol rather than using a new ICMP message. So + ILNP defines a new ICMP Locator Update message for both IPv4 and + IPv6. + +6.2. Network Connectivity/Locator Changes + + As a DNS performance optimisation, the LP DNS resource record MAY be + used to avoid requiring each node on a subnetwork to update its DNS + L64 record entries when that subnetwork's location (e.g., upstream + connectivity) changes [RFC6742]. This can reduce the number of DNS + updates required when a subnetwork moves from Order (number of nodes + on subnetwork) to Order(1). + + In this case, the nodes on the subnetwork each would have an LP + record pointing to a common FQDN used to name that subnetwork. In + turn, that subnetwork's domain name would have one or more L64 + record(s) in the DNS. Since the contents of an LP record are stable, + relatively long DNS TTL values can be associated with these records + facilitating DNS caching. By contrast, the DNS TTL of an L32 or L64 + record for a mobile or multihomed node should be small. Experimental + work at the University of St Andrews indicates that the DNS continues + to work well even with very low (e.g., zero) DNS TTL values [BA11]. + + Correspondents of a node on a mobile subnetwork using this DNS + performance optimisation would initially perform a normal FQDN lookup + for a node. If that lookup returned another FQDN in an LP record as + additional data, then the correspondent would perform a lookup on + that FQDN and expect an L32 or L64 record returned as additional + data, in order to learn the Locator value to use to reach that target + node. (Of course, a lookup that did not return any ILNP-related DNS + records would result in an ordinary IPv4 session or ordinary IPv6 + session being initiated, instead.) + +7. Subnetting + + For ILNPv4 and ILNPv6, the Locator value includes the subnetting + information, as that also is topological information. As well as + being architecturally correct, the placement of subnetting as part of + the Locator is also convenient from an engineering point of view in + both IPv4 and IPv6. + + + + + +Atkinson & Bhatti Experimental [Page 17] + +RFC 6741 ILNP Engineering November 2012 + + + We consider that a Locator value, L consists of two parts: + + - L_pp: the Locator prefix part, which occupies the most significant + bits in the address (for both ILNPv4 and ILNPv6). + + - L_ss: Locator subnetwork selector, which occupies bits just after + the L_pp. + + For each of ILNPv4 and ILNPv6, L_pp gets its value from the provider- + assigned routing prefix for IPv4 and IPv6, respectively. For L_ss, + in each case of ILNPv4 and ILNPv6, the L_ss bits are located in the + part of the address space which you might expect them to be located + if IPv4 or IPv6 addresses were being used, respectively. + +7.1. Subnetting for ILNPv6 + + For ILNPv6, recall that the Locator value is encoded to be + syntactically similar to an IPv6 address prefix, as shown in Figure + 7.1. + + /* IPv6 */ + | 3 | 45 bits | 16 bits | 64 bits | + +---+---------------------+-----------+-------------------------+ + |001|global routing prefix| subnet ID | Interface Identifier | + +---+---------------------+-----------+-------------------------+ + + /* ILNPv6 */ + | 64 bits | 64 bits | + +---+---------------------+-----------+-------------------------+ + | Locator (L64) | Node Identifier (NID) | + +---+---------------------+-----------+-------------------------+ + +<-------- L_pp --------->+<- L_ss -->+ + + L_pp = Locator prefix part (assigned IPv6 prefix) + L_ss = Locator subnet selector (locally managed subnet ID) + + Figure 7.1: IPv6 Address Format [RFC3587] as Used in ILNPv6, + Showing How Subnets Can Be Identified + + Note that the subnet ID forms part of the Locator value. Note also + that [RFC6177] allows the global routing prefix to be more than 45 + bits, and for the subnet ID to be smaller, but still preserving the + 64-bit size of the Locator. + + + + + + + + +Atkinson & Bhatti Experimental [Page 18] + +RFC 6741 ILNP Engineering November 2012 + + +7.2. Subnetting for ILNPv4 + + For ILNPv4, the L_pp value is an IPv4 routing prefix as used today, + which is typically less than 32 bits. However, the ILNPv4 Locator + value is carried in the 32-bit IP Address space, so the bits not used + for the routing prefix could be used for L_ss, e.g., for a /24 IPv4 + prefix, the situation would be as shown in Figure 7.2. + + 24 bits 8 bits + +------------------------+----------+ + | Locator (L32) | + +------------------------+----------+ + +<------- L_pp --------->+<- L_ss ->+ + + L_pp = Locator prefix part (assigned IPv4 prefix) + L_ss = Locator subnet selector (locally managed subnet ID) + + Figure 7.2: IPv4 Address Format for /24 IPv4 Prefix, as Used in + ILNPv4, Showing How Subnets Can Be Identified + + Note that the L_ss occupies bits that in an IPv4 address would + normally be the host part of the address, which the site network + could use for subnetting in any case. + +7.3. Subnetting for Router-Router Links in IPv6/ILNPv6 + + There is a special case of /127 prefixes used in router-router, + point-to-point links for IPv6 [RFC6164]. ILNPv6 does not preclude + such use. + +8. DNS Considerations + + ILNP makes use of DNS for name resolution, as does IP. Unlike IP, + ILNP also uses DNS to support features such as mobility and + multihoming. While such usage is appropriate use of the DNS, it is + important to discuss operational and engineering issues that may + impact DNS usage. + +8.1. Secure Dynamic DNS Update + + When a host that expects incoming connections changes one or more of + its Locator values, the host normally uses the IETF Secure Dynamic + DNS Update protocol [RFC3007] to update the set of currently valid + Locator values associated with its FQDN. This ensures that the + authoritative DNS server for its FQDN will be able to generate an + accurate set of Locator values if the DNS server receives DNS name + resolution request for its FQDN. + + + + +Atkinson & Bhatti Experimental [Page 19] + +RFC 6741 ILNP Engineering November 2012 + + + Liu and Albitz [LA06] report that Secure Dynamic DNS Update has been + supported on the client-side for several years now in widely deployed + operating systems (e.g., MS Windows, Apple Mac OS X, UNIX, and Linux) + and also in DNS server software (e.g., BIND). Publicly available + product data sheets indicate that some other DNS server software + packages, such as that from Nominum, also support this capability. + + For example, Microsoft Windows XP (and later versions), the freely + distributable BIND DNS software package (used in Apple Mac OS X and + in most UNIX systems), and the commercial Nominum DNS server all + implement support for Secure Dynamic DNS Update and are known to + interoperate [LA06]. There are credible reports that when a site + deploys Microsoft's Active Directory, the site (silently) + automatically deploys Secure Dynamic DNS Update [LA06]. So, many + sites have already deployed Secure Dynamic DNS Update even though + they are not actively using it (and might not be aware they have + already deployed that protocol) [LA06]. + + So DNS update via Secure Dynamic DNS Update is not only standards- + based, but also readily available in widely deployed systems today. + +8.2. New DNS RR Types + + As part of this proposal, additional DNS resource records have been + proposed in a separate document [RFC6742]. These new records are + summarised in Table 6.1. + + new DNS RR type | Purpose + -----------------+------------------------------------------------ + NID | store the value of a Node Identifier + L32 | store the value of a 32-bit Locator for ILNPv4 + L64 | store the value of a 64-bit Locator for ILNPv6 + LP | points to a (several) L32 and/or L64 record(s) + -----------------+------------------------------------------------ + + Table 6.1. Summary of new DNS RR Types for ILNP + + With this proposal, mobile or multihomed nodes and sites are expected + to use the existing "Secure Dynamic DNS Update" protocol to keep + their Node Identifier (NID) and Locator (L32 and/or L43) records + correct in their authoritative DNS server(s) [RFC3007] [RFC6742]. + + Reverse DNS lookups, to find a node's FQDN from the combination of a + Locator and related Identifier value, can be performed as at present. + + + + + + + +Atkinson & Bhatti Experimental [Page 20] + +RFC 6741 ILNP Engineering November 2012 + + +8.3. DNS TTL Values for ILNP RRS Types + + Existing DNS specifications require that DNS clients and DNS + resolvers honour the TTL values provided by the DNS servers. In the + context of this proposal, short DNS TTL values are assigned to + particular DNS records to ensure that the ubiquitous DNS caching + resolvers do not cache volatile values (e.g., Locator records of a + mobile node) and consequently return stale information to new + requestors. + + The TTL values for L32 and L64 records may have to be relatively low + (perhaps a few seconds) in order to support mobility and multihoming. + Low TTL values may be of concern to administrators who might think + that this would reduce efficacy of DNS caching increase DNS load + significantly. + + Previous research by others indicates that DNS caching is largely + ineffective, with the exception of NS records and the addresses of + DNS servers referred to by NS records [SBK02]. This means DNS + caching performance and DNS load will not be adversely affected by + assigning very short TTL values (down to zero) to the Locator records + of typical nodes for an edge site [BA11]. It also means that it is + preferable to deploy the DNS server function on nodes that have + longer DNS TTL values, rather than on nodes that have shorter DNS TTL + values. + + LP records normally are stable and will have relatively long TTL + values, even if the L32 or L64 records they point to have values that + have relatively low TTL values. + + Identifier values might be very long-lived (e.g., days) when they + have been generated from an IEEE MAC address on the system. + Identifier values might have a shorter lifetime (e.g., hours or + minutes) if they have been cryptographically generated [RFC3972], + have been created by the IPv6 Privacy Extensions [RFC4941], or + otherwise have the EUI-64 scope bit set to "local-scope". Note that + when ILNP is used, the cryptographic generation method described in + RFC 3972 is used only for the Identifier, omitting the Locator, + thereby preserving roaming capability. Note that a given ILNP + session normally will use a single Identifier value for the lifetime + of that ILNP session. + +8.4. IP/ILNP Dual Operation and Transition + + During a long transition period, a node that is ILNP-capable SHOULD + have not only NID and L32/L64 (or NID and LP) records present in its + authoritative DNS server but also SHOULD have A/AAAA records in the + DNS for the benefit of non-upgraded nodes. Then, when any CN + + + +Atkinson & Bhatti Experimental [Page 21] + +RFC 6741 ILNP Engineering November 2012 + + + performs an FQDN lookup for that node, it will receive the A/AAAA + with the appropriate NID, L32/L64 records, and/or LP records as + "additional data". + + Existing DNS specifications require that a DNS resolver or DNS client + ignore unrecognised DNS record types. So, gratuitously appending NID + and Locator (i.e., L32, L64, or LP) records as "additional data" in + DNS responses to A/AAAA queries ought not to create any operational + issues. So, IP only nodes would use the A/AAAA RRs, but ILNP-capable + nodes would be able to use the NID, L32/L64 and/or LP records are + required. + + There is nothing to prevent this capability being implemented + strictly inside a DNS server, whereby the DNS server synthesises a + set of A/AAAA records to advertise from the NID and Locator (i.e., + L32, L64, or LP) values that the node has kept updated in that DNS + server. Indeed, such a capability may be desirable, reducing the + amount of manual configuration required for a site, and reducing the + potential for errors as the A/AAAA records would be automatically + generated. + +9. IP Security for ILNP + + The primary conceptual difference from ordinary IP security (IPsec) + is that ILNP IP Security omits all use of, and all reference to, + Locator values. This leads to several small, but important, changes + to IPsec when it is used with ILNP sessions. + +9.1. IPsec Security Association Enhancements for ILNP + + IPsec Security Associations for ILNP only include the Identifier + values for the endpoints, and omit the Locator values. As an + implementation detail, ILNP implementations MUST be able to + distinguish between different Security Associations with ILNP + correspondents (at different locations, with different ILNP Nonce + values in use) that happen to use the same Identifier values (e.g., + due to an inadvertent Identifier collision when using identifier + values generated by using the IPv6 Privacy Addressing extension). + One possible way to distinguish between such different ILNP sessions + is to maintain a mapping between the IPsec Security Association + Database (SAD) entry and the corresponding ILCC entry. + + Consistent with this enhancement to the definition of an IPsec + Security Association, when processing received IPsec packets + associated with an ILNP session, ILNP implementations ignore the + Locator bits of the received packet and only consider the Identifier + bits. This means, for example, that if an ILNP correspondent node + + + + +Atkinson & Bhatti Experimental [Page 22] + +RFC 6741 ILNP Engineering November 2012 + + + moves to a different subnetwork, and thus is using a different Source + Locator in the header of its ILNP IPsec packets, the ILNP session + will continue to work and will continue to be secure. + + Since implementations of ILNP are also required to support IP, + implementers need to ensure that ILNP IPsec Security Associations can + be distinguished from ordinary IPsec Security Associations. The + details of this are left to the implementer. As an example, one + possible implementation strategy would be to retain a single IPsec + Security Association Database (SAD), but add an internal flag bit to + each entry of that IPsec SAD to indicate whether ILNP is in use for + that particular IPsec Security Association. + +9.2. IP Authentication Header Enhancements for ILNP + + Similarly, for an ILNP session using IPsec, the IPsec Authentication + Header (AH) only includes the Identifier values for the endpoints in + its authentication calculations, and it omits the Source Locator and + Destination Locator fields from its authentication calculations. + This enables IPsec AH to work well even when used with ILNP localised + numbering [RFC6748] or other situations where a Locator value might + change while the packet travels from origin to destination. + +9.3. Key Management Considerations + + In order to distinguish at the network-layer between multiple ILNP + nodes that happen to be using the same Node Identifier values (e.g., + because the identifier values were generated using the IPv6 Privacy + Addressing method), key management packets being used to set up an + ILNP IPsec session MUST include the ILNP Nonce Option. + + Similarly, key management protocols used with IPsec are enhanced to + deprecate use of IP Addresses as identifiers and to substitute the + use of the new Node Identifier values for that purpose. This results + in an ILNP IPsec Security Association that is independent of the + Locator values that might be used. + + For ILNPv6 implementations, the ILNP Node Identifier (64-bits) is + smaller than the IPv6 Address (128-bits). So support for ILNPv6 + IPsec is accomplished by zeroing the upper-64 bits of the IPv6 + Address fields in the application-layer key management protocol, + while retaining the Node Identifier value in the lower-64 bits of the + application-layer key management protocol. + + + + + + + + +Atkinson & Bhatti Experimental [Page 23] + +RFC 6741 ILNP Engineering November 2012 + + + For ILNPv4 implementations, enhancements to the key management + protocol likely will be needed, because existing key management + protocols rely on 32-bit IPv4 addresses, while ILNP Node Identifiers + are 64-bits. Such enhancements are beyond the scope of this + specification. + +10. Backwards Compatibility and Incremental Deployment + + Experience with IPv6 deployment over the past many years has shown + that it is important for any new network protocol to provide + backwards compatibility with the deployed IP base and should be + incrementally deployable, ideally requiring modification of only + those nodes that wish to use ILNP and not requiring the modification + of nodes that do not intend to use ILNP. The two instances of ILNP, + ILNPv4 and ILNPv6, are intended to be, respectively, backwards + compatible with, and incrementally deployable on, the existing IPv4 + and IPv6 installed bases. Indeed, ILNPv4 and ILNPv6 can each be + seen, from an engineering viewpoint, as supersets of the IPv4 and + IPv6, respectively. + + However, in some cases, ILNP introduces functions that supersede + equivalent functions available in IP. For example, ILNP has a + mobility model, and so it does not need to use the models for Mobile + IPv4 or Mobile IPv6. + + As ILNP changes, the use of end-to-end namespaces, for the most part, + it is only end-systems that need to be modified. However, in order + to leverage existing engineering (e.g., existing protocols), in some + cases, there is a compromise, and these are highlighted in this + section. + +10.1. Priorities in the Design of ILNPv6 and ILNPv4 + + In the engineering design of ILNPv6 and ILNPv4, we have used the + following priorities. In some ways, this choice is arbitrary, and it + may be equally valid to "invert" these priorities for a different + architectural and engineering design. + + 1. Infrastructure + + As much of the deployed IP network infrastructure should be used + without change. That is, routers and switches should require minimal + or zero modifications in order to run ILNP. As much as possible of + the existing installed base of core protocols should be reused. + + + + + + + +Atkinson & Bhatti Experimental [Page 24] + +RFC 6741 ILNP Engineering November 2012 + + + 2. Core protocols + + As much of the deployed network control protocols, such as routing, + should be used without change. That is, existing routing protocols + and switch configuration should require minimal or zero modifications + in order to run ILNP. + + 3. Scope of end-system changes + + Any nodes that do not need to run ILNP should not need to be + upgraded. It should be possible to have a site network that has a + mix of IP-only and ILNP-capable nodes without any changes required to + the IP-only nodes. + + 4. Applications + + There should be minimal impact on applications, even though ILNP + requires end-to-end protocols to be upgraded. Indeed, for those + applications that are "well behaved" (e.g., do not use IP Address + values directly for application state or application configuration), + there should be little or no effort required in enabling them to + operate over ILNP. + + Each of these items is discussed in its own section below. + +10.2. Infrastructure + + ILNP is designed to be deployed on existing infrastructure. No new + infrastructure is required to run ILNP as it will be implemented as a + software upgrade impacting only end-to-end protocols. Existing + routing protocols can be reused: no new routing protocols are + required. This means that network operators and service providers do + not need to learn about, test, and deploy new protocols, or change + the structure of their network in order for ILNP to be deployed. + Exceptionally, edge routers supporting ILNPv4 hosts will need to + support an enhanced version of ARP. + +10.3. Core Protocols + + Existing routing and other control protocols should not need to + change in devices such as switches and routers. We believe this to + be true for ILNPv6. However, for ILNPv4, we believe that ARP will + need to be enhanced in edge routers (or Layer 3 switches) that + support ILNPv4 hosts. Backbone and transit routers still ought not + require changes for either ILNPv4 or ILNPv6. + + + + + + +Atkinson & Bhatti Experimental [Page 25] + +RFC 6741 ILNP Engineering November 2012 + + + For both ILNPv4 and ILNPv6, the basic packet format for packets + reuses that format that is seen by routers for IPv4 and IPv6, + respectively. Specifically, as the ILNP Locator value is always a + routing prefix (either IPv4 or IPv6), routing protocols should work + unchanged. + + Both ILNPv4 and ILNPv6 introduce new header options (e.g., Nonce + Option messages) and ICMP messages (e.g., Locator Update messages) + that are used to enable end-to-end signalling. For packet + forwarding, depending on the forwarding policies used by some + providers or site border routers, there may need to be modifications + to those policies to allow the new header options and new ICMP + messages to be forwarded. However, as the header options and new + ICMP messages are end-to-end, such modifications are likely to be in + configuration files (or firewall policy on edge routers), as core + routers do NOT need to parse and act upon the information contained + in the header options or ICMP messages. + +10.4. Scope of End-System Changes + + Only end-systems that need to use ILNP need to be updated in order + for ILNP to be used at a site. + + There are three exceptions to this statement as follows: + + a) ILNPv4 ARP: as the Identifier value for IPv4 cannot fit into the + normal 20-byte IPv4 packet header (a header extension is used), + ARP must be modified. This only impacts end-systems that use + ILNPv4 and those switches or site border routers that are the + first hop from an ILNPv4 node. For ILNPv6, as the I and L values + fit into the existing basic IPv6 packet, IPv6 Neighbour Discovery + can operate without modification. + + b) Use of IP NAT: Where IP NAT or NAPT is in use for a site, existing + NAT/NAPT device will rewrite address fields in ILNPv4 packets or + ILNPv6 packets. To avoid this, the NAT should either (i) be + configured to allow the pass-through of packets originating from + ILNP-capable nodes (e.g., by filtering on source address fields in + the IP header); or (ii) should be enhanced to recognise ILNPv4 or + ILNPv6 packets (e.g., by looking for the ILNP Nonce Option). + + c) Site Border Routers (SBRs) in ILNP Advanced Deployment scenarios: + There are options to use an ILNP-capable Site Border Router (SBR) + as described in another document [RFC6748]. In such scenarios, + the SBR(s) need to be ILNP-capable. + + + + + + +Atkinson & Bhatti Experimental [Page 26] + +RFC 6741 ILNP Engineering November 2012 + + + Other than these exceptions, it is entirely possible to have a site + that uses a mix of IP and ILNP nodes and requires no changes to nodes + other than the nodes that wish to use ILNP. For example, if a user + on a site wishes to have his laptop use ILNPv6, only that laptop + would need to have an upgraded stack: no other devices (end-systems, + Layer 2 switches or routers) at that site would need to be upgraded. + +10.5. Applications + + As noted, in the Architecture Description [RFC6740], those + applications that do not use IP Address values in application state + or configuration data are considered to be "well behaved". + Applications that work today through a NAT or Network Address Port + Translation (NAPT) device without application-specific support are + also considered "well behaved". Such applications might use DNS + FQDNs or application-specific name spaces. (Note Well: application- + specific name spaces should not be derived from IP Address values.) + + For well-behaved applications, replacing IP with ILNP should have no + impact. That is, well-behaved applications should work unmodified + over ILNP. + + Those applications that directly use IP Address values in application + state or configuration will need to be modified for operation over + ILNP. Examples of such applications include the following: + + - FTP: which uses IP Address values in the application-layer + protocol. In practice, use of Secure Copy (SCP) is growing, while + use of FTP is either flat or declining, in part due to the improved + security provided by SCP. + + - SNMP: which uses IP Address values in MIB definitions, and values + derived from IP Address values in SNMP object names. + + Further experimentation in this area is planned to validate these + details. + +10.6. Interworking between IP and ILNP + + A related topic is interworking: for example, how would an IPv6 node + communicate with an ILNPv6 node? Currently, we make the assumption + that ILNP nodes "drop down" to using IP when communicating with a + non-ILNP capable node, i.e., there is no interworking as such. In + the future, it may be beneficial to define interworking scenarios + that do not rely on having ILNP nodes fall back to IP, for example, + by the use of suitable protocol translation gateways or middleboxes. + + + + + +Atkinson & Bhatti Experimental [Page 27] + +RFC 6741 ILNP Engineering November 2012 + + + For now, a simplified summary of the process for interaction between + ILNP hosts and non-ILNP hosts is as follows: + + a) For a host initiating communication using DNS, the resolution of + the FQDN for the remote host will return at least one NID record + and at least one of an L32 record (for ILNPv4) or an L64 record + (for ILNPv6). Then, the host knows that the remote host supports + ILNP. + + b) When a host has I and L values for a remote host, the initial + packet to initiate communication MUST contain a Nonce Header + [RFC6746] [RFC6744] that indicates to the remote host that this + packet is attempting to set up an ILNP session. + + c) When a receiving host sees a Nonce Header, if it DOES support ILNP + it will proceed to set up an ILNP session. + + d) When a receiving host sees a Nonce Header, if it DOES NOT support + ILNP, it will reject the packet and this will be indicated to the + sender through an ICMP message [RFC6743] [RFC6745]. Upon + receiving the ICMP messages, the sender will re-initiate + communication using standard IPv4 or IPv6. + + Many observers in the community expect IPv4 to remain in place for a + long time even though IPv6 has been available for over a decade. + With a similar anticipation, it is likely that in the future there + will be a mixed environment of both IP and ILNP hosts. Until there + is a better understanding of the deployment and usage scenarios that + will develop, it is not clear what interworking scenarios would be + useful to define and focus on between IP and ILNP. + +11. Security Considerations + + There are numerous security considerations for ILNP from an + engineering viewpoint. Overall, ILNP and its capabilities are no + less secure than IP and equivalent IP capabilities. In some cases, + ILNP has the potential to be more secure, or offer security + capability in a more harmonised manner, for example, with ILNP's use + of IPsec in conjunction with multihoming and mobility. [RFC6740] + describes several security considerations that apply to ILNP and is + included here by reference. + + ILNP offers an enhanced version of IP security (IPsec). The details + of IP Security for ILNP were described separately above. All ILNP + implementations MUST support the use of the IP Authentication Header + (AH) for ILNP and also the IP Encapsulating Security Payload (ESP) + for ILNP, but deployment and use of IPsec for ILNP remains a matter + for local operational security policy. + + + +Atkinson & Bhatti Experimental [Page 28] + +RFC 6741 ILNP Engineering November 2012 + + +11.1. Authenticating ICMP Messages + + Separate documents propose a new IPv4 Option [RFC6746] and a new IPv6 + Destination Option [RFC6744]. Each of these options can be used to + carry an ILNP Nonce value end-to-end between communicating nodes. + That nonce provides protection against off-path attacks on an ILNP + session. These ILNP Nonce Options are used ONLY for ILNP and not for + IP. The nonce values are exchanged in the initial packets of an ILNP + session by including them in those initial/handshake packets. + + ALL ICMP Locator Update messages MUST include an ILNP Nonce Option + and MUST include the correct ILNP Nonce value for the claimed sender + and intended recipient of that ICMP Locator Update message. There + are no exceptions to this rule. ICMP Locator Update messages MAY be + protected by IPsec, but they still MUST include an ILNP Nonce Option + and the ILNP Nonce Option still MUST include the correct ILNP Nonce + value. + + When a node has an active ILNP session, and that node changes its + Locator set, it SHOULD include the appropriate ILNP Nonce Option in + the first few data packets sent using a new Locator value so that the + recipient can validate the received data packets as valid (despite + having an unexpected Source Locator value). + + Any ILNP Locator Update messages received without an ILNP Nonce + Option MUST be discarded as forgeries. + + Any ILNP Locator Update messages received with an ILNP Nonce Option, + but that do NOT have the correct ILNP Nonce value inside the ILNP + Nonce Option, MUST be discarded as forgeries. + + When the claimed sender of an ICMP message is known to be a current + ILNP correspondent of the recipient (e.g., has a valid, non-expired, + ILCC entry), then any ICMP error messages from that claimed sender + MUST include the ILNP Nonce Option and MUST include the correct ILNP + Nonce value (i.e., correct for that sender recipient pair) in that + ILNP Nonce Option. + + When the claimed sender of an ICMP error message is known to be a + current ILNP correspondent of the recipient (e.g., has a valid, non- + expired, ILCC entry), then any ICMP error messages from that claimed + sender that are received without an ILNP Nonce Option MUST be + discarded as forgeries. + + When the claimed sender of an ICMP error message is known to be a + current ILNP correspondent of the recipient (e.g., has a valid, non- + expired, ILCC entry), then any ICMP error messages from that claimed + + + + +Atkinson & Bhatti Experimental [Page 29] + +RFC 6741 ILNP Engineering November 2012 + + + sender that contain an ILNP Nonce Option, but that do NOT have the + correct ILNP Nonce value inside the ILNP Nonce Option, MUST be + discarded as forgeries. + + ICMP messages (not including ICMP Locator Update messages) with a + claimed sender that is NOT known to be a current ILNP correspondent + of the recipient (e.g., does not have a valid, non-expired, ILCC + entry) MAY include the ILNP Nonce Option, but, in this case, the ILNP + Nonce Option is ignored by the recipient upon receipt, since the + recipient has no way to authenticate the received ILNP Nonce value. + + Received ICMP messages (not including ICMP Locator Update messages) + with a claimed sender that is NOT known to be a current ILNP + correspondent of the recipient (e.g., does not have a valid, non- + expired, ILCC entry) do NOT require the ILNP Nonce Option because the + security risks are no different than for deployed IPv4 and IPv6 -- + provided that the received ICMP message is not an ICMP Locator Update + message. Such ICMP messages (e.g., Destination Unreachable, Packet + Too Big) might legitimately originate in an intermediate system along + the path of an ILNP session. That intermediate system might not be + ILNP capable. Even if ILNP capable itself, that intermediate system + might not know which of the packets it forwards are part of ILNP + sessions. + + When ILNP is in use, IP Security for ILNP also MAY be used to protect + stronger protections for ICMP packets associated with an ILNP + session. Even in this case, the ILNP Nonce Option also MUST be + present and MUST contain the correct ILNP Nonce value. This + simplifies packet processing and enables rapid discard of any forged + packets from an off-path attacker that lack either the ILNP Nonce + Option or the correct ILNP Nonce value -- without requiring + computationally expensive IPsec processing. Received ICMP messages + that are protected by ILNP IP Security, but fail the recipient's + IPsec checks, MUST be dropped as forgeries. If a deployment chooses + to use ILNP IPsec ESP to protect its ICMP messages and is NOT also + using ILNP IPsec AH with those messages, then the ILNP Nonce Option + MUST be placed in the ILNP packet after the ILNP IPsec ESP header, + rather than before the ILNP IPsec ESP header, to ensure that the + Nonce Option is protected in transit. + + Receipt of any ICMP message that is dropped or discarded as a forgery + SHOULD cause the details of the received forged ICMP packet (e.g., + Source and Destination Locators / Source and Destination Identifiers + / Source and Destination IP Addresses, ICMP message type, receiving + interface, receive date, receive time) to be logged in the receiving + system's security logs. Implementations MAY rate-limit such logging + + + + + +Atkinson & Bhatti Experimental [Page 30] + +RFC 6741 ILNP Engineering November 2012 + + + in order to reduce operational risk of denial-of-service attacks on + the system logging functions. The details of system logging are + implementation specific. + +11.2. Forged Identifier Attacks + + The ILNP Communication Cache (ILCC) contains two unidirectional nonce + values (one used in control messages sent by this node, a different + one used to authenticate messages from the other node) for each + active or recent ILNP session. The ILCC also contains the currently + valid set of Locators and set of Identifiers for each correspondent + node. + + If a received ILNP packet contains valid Identifier values and a + valid Destination Locator, but contains a Source Locator value that + is not present in the ILCC, the packet MUST be dropped as an invalid + packet and a security event SHOULD be logged, UNLESS the packet also + contains a Nonce Destination Option with the correct value used for + packets from the node with that Source Identifier to this node. This + prevents an off-path attacker from stealing an existing ILNP session. + +12. Privacy Considerations + + There are no additional privacy issues created by ILNP compared to + IP. Please see Section 10 of [RFC6740] for more detailed discussion + of Privacy Considerations. + + ILNPv6 supports use of the IPv6 Privacy Extensions for Stateless + Address Autoconfiguration in IPv6 [RFC4941] to enable identity + privacy (see also Section 2). + + Location Privacy can be provided by locator rewriting techniques as + described in Section 7 of [RFC6748]. + + A description of various possibilities for obtaining both identity + privacy and location privacy with ILNP can be found in [BAK11]. + +13. Operational Considerations + + This section covers various operational considerations relating to + ILNP, including potential session liveness and reachability + considerations and Key Management considerations. Again, the + situation is similar to IP, but it is useful to explain the issues in + relation to ILNP nevertheless. + + + + + + + +Atkinson & Bhatti Experimental [Page 31] + +RFC 6741 ILNP Engineering November 2012 + + +13.1. Session Liveness and Reachability + + For bidirectional flows, such as a TCP/ILNP session, each node knows + whether the current path in use is working by the reception of data + packets, acknowledgements, or both. Therefore, as with TCP/IP, + TCP/ILNP does not need special path probes. UDP/ILNP sessions with + acknowledgements work similarly and do not need special path probes. + + In the deployed Internet, the sending node for a UDP/IP session + without acknowledgements does not know for certain that all packets + are received by the intended receiving node. Such UDP/ILNP sessions + have the same properties as UDP/IP sessions in this respect. The + receiver(s) of such an UDP/ILNP session SHOULD send a gratuitous IP + packet containing an ILNP Nonce Option to the sender, in order to + enable the receiver to subsequently send ICMP Locator Updates if + appropriate [RFC6744]. In this case, UDP/ILNP sessions fare better + than UDP/IP sessions, still without using network path probes. + + A mobile (or multihomed) node may change its connectivity more + quickly than DNS can be updated. This situation is unlikely, + particularly given the widespread use of link-layer mobility + mechanisms (e.g., GSM, IEEE 802 bridging) in combination with + network-layer mobility. However, the situation is equivalent to the + situation where a traditional IP node is moving faster than the + Mobile IPv4 or Mobile IPv6 agents/servers can be updated with the + mobile node's new location. So the issue is not new in any way to + ILNP. In all cases, Mobile IPv4 and Mobile IPv6 and ILNP, a node + moving that quickly might be temporarily unreachable until it remains + at a given network-layer location (e.g., IP subnetwork, ILNP Locator + value) long enough for the location update mechanisms (for Mobile + IPv4, for Mobile IPv6, or ILNP) to catch up. + + Another potential issue for IP is what is sometimes called "Path + Liveness" or, in the case of ILNP, "Locator Liveness". This refers + to the question of whether an IP packet with a particular destination + Locator value will be able to reach the intended destination network + or not, given that some otherwise valid paths might be unusable by + the sending node (e.g., due to security policy or other + administrative choice). In fact, this issue has existed in the IPv4 + Internet for decades. + + For example, an IPv4 server might have multiple valid IP Addresses, + each advertised to the world via a DNS A record. However, at a given + moment in time, it is possible that a given sending node might not be + able to use a given (otherwise valid) destination IPv4 address in an + IP packet to reach that IPv4 server. + + + + + +Atkinson & Bhatti Experimental [Page 32] + +RFC 6741 ILNP Engineering November 2012 + + + Indeed, for ILNPv6, as the ILNP packet reuses the IPv6 packet header + and uses IPv6 routing prefixes as Locator values, such liveness + considerations are no worse than they are for IPv6 today. For + example, for IPv6, if a host, H, performs a DNS lookup for an FQDN + for remote host F, and receives a AAAA RR with IPv6 address F_A, this + does not mean necessarily that H can reach F on its F_A using its + current connectivity, i.e., an IPv6 path may not be available from H + to F at that point in time. + + So we see that using an Identifier/Locator Split architecture does + not create this issue, nor does it make this issue worse than it is + with the deployed IPv4 Internet. + + In ILNP, the same conceptual approach described in [RFC5534] (Locator + Pair Exploration for SHIM6) can be reused. Alternatively, an ILNP + node can reuse the existing IPv4 methods for determining whether a + given path to the target destination is currently usable, for which + existing methods leverage transport-layer session state information + that the communicating end systems are already keeping for transport- + layer protocol reasons. + + Lastly, it is important to note that the ICMP Locator Update + mechanism described in [RFC6743] [RFC6745] is a performance + optimisation, significantly shortening the network-layer handoff time + if/when a correspondent changes location. Architecturally, using + ICMP is no different from using UDP, of course. + +13.2. Key Management Considerations + + ILNP potentially has advantages over either form of Mobile IP with + respect to key management, given that ILNP is using Secure Dynamic + DNS Update -- which capability is much more widely available today in + deployed desktop and server environments (e.g., Microsoft Windows, + Mac OS X, Linux, other UNIX), as well as being widely available today + in deployed DNS server software (e.g., Microsoft and the freely + available BIND) and appliances [LA06], than the security enhancements + needed by either Mobile IPv4 or Mobile IPv6. + + In the IESG, there is work in progress that addresses use of DNS to + support key management for entities having DNS Fully Qualified Domain + Names. + +13.3. Point-to-Point Router Links + + As a special case, for the operational reasons described in + [RFC6164], ILNPv6 deployments MAY continue to use classic IPv6 with a + /127 routing prefix on router to router point-to-point links (e.g., + SONET/SDH). Because an ILNPv6 packet and an IPv6 packet are + + + +Atkinson & Bhatti Experimental [Page 33] + +RFC 6741 ILNP Engineering November 2012 + + + indistinguishable for forwarding purposes to a transit router, this + should not create any operational difficulty for ILNPv6 traffic + travelling over such links. + +14. Referrals and Application Programming Interfaces + + This section is concerned with support for using existing ("legacy") + applications over ILNP, including both referrals and Application + Programming Interfaces (APIs). + + ILNP does NOT require that well-behaved applications be modified to + use a new networking API, nor does it require applications be + modified to use extensions to an existing API. Existing well-behaved + IP applications should work over ILNP without modification using + existing networking APIs. + +14.1. BSD Sockets APIs + + The existing BSD Sockets API can continue to be used with ILNP + underneath the API. That API can be implemented in a manner that + hides the underlying protocol changes from the applications. For + example, the combination of a Locator and an Identifier can be used + with the API in the place of an IPv6 address. + + So it is believed that existing IP address referrals can continue to + work properly in most cases. For a rapidly moving target node, + referrals might break in at least some cases. The potential for + referral breakage is necessarily dependent upon the specific + application and implementation being considered. + + It is suggested, however, that a new, optional, more abstract, C + language API be created so that new applications may avoid delving + into low-level details of the underlying network protocols. Such an + API would be useful today, even with the existing IPv4 and IPv6 + Internet, whether or not ILNP were ever widely deployed. + +14.2. Java (and Other) APIs + + Most existing Java APIs already use abstracted network programming + interfaces, for example, in the java.Net.URL class. Because these + APIs already hide the low-level network-protocol details from the + applications, the applications using these APIs (and the APIs + themselves) don't need any modification to work equally well with + IPv4, IPv6, ILNP, and probably also HIP. + + Other programming languages, such as C++, python and ruby, also + provide higher-level APIs that abstract away from sockets, even + though sockets may be used beneath those APIs. + + + +Atkinson & Bhatti Experimental [Page 34] + +RFC 6741 ILNP Engineering November 2012 + + +14.3. Referrals in the Future + + The approach proposed in [REFERRAL] appears to be very suitable for + use with ILNP, in addition to being suitable for use with the + deployed Internet. Protocols using that approach would not need + modification to have their referrals work well with IPv4, IPv6, ILNP, + and probably also other network protocols (e.g., HIP). + + A sensible approach to referrals is to use FQDNs, as is commonly done + today with web URLs. This approach is highly portable across + different network protocols, even with both the IPv4 Internet or the + IPv6 Internet. + +15. References + +15.1. Normative References + + [IEEE-EUI] IEEE, "Guidelines for 64-bit Global Identifier (EUI-64) + Registration Authority", <http://standards.ieee.org/ + regauth/oui/tutorials/EUI64.html>, IEEE, Piscataway, NJ, + USA, March 1997. + + [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate + Requirement Levels", BCP 14, RFC 2119, March 1997. + + [RFC3007] Wellington, B., "Secure Domain Name System (DNS) Dynamic + Update", RFC 3007, November 2000. + + [RFC3177] IAB and IESG, "IAB/IESG Recommendations on IPv6 Address + Allocations to Sites", RFC 3177, September 2001. + + [RFC3587] Hinden, R., Deering, S., and E. Nordmark, "IPv6 Global + Unicast Address Format", RFC 3587, August 2003. + + [RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless + Address Autoconfiguration", RFC 4862, September 2007. + + [RFC4984] Meyer, D., Ed., Zhang, L., Ed., and K. Fall, Ed., + "Report from the IAB Workshop on Routing and + Addressing", RFC 4984, September 2007. + + [RFC6177] Narten, T., Huston, G., and L. Roberts, "IPv6 Address + Assignment to End Sites", BCP 157, RFC 6177, March 2011. + + [RFC6740] Atkinson, R. and S. Bhatti, "Identifier-Locator Network + Protocol (ILNP) Architectural Description", RFC 6740, + November 2012. + + + + +Atkinson & Bhatti Experimental [Page 35] + +RFC 6741 ILNP Engineering November 2012 + + + [RFC6742] Atkinson, R., Bhatti, S. and S. Rose, "DNS Resource + Records for the Identifier-Locator Network Protocol + (ILNP)", RFC 6742, November 2012. + + [RFC6743] Atkinson, R. and S. Bhatti, "ICMPv6 Locator Update + Message", RFC 6743, November 2012. + + [RFC6744] Atkinson, R. and S. Bhatti, "IPv6 Nonce Destination + Option for the Identifier-Locator Network Protocol for + IPv6 (ILNPv6)", RFC 6744, November 2012. + + [RFC6745] Atkinson, R. and S. Bhatti, "ICMP Locator Update + Message for the Identifier-Locator Network Protocol for + IPv4 (ILNPv4)", RFC 6745, November 2012. + + [RFC6746] Atkinson, R. and S.Bhatti, "IPv4 Options for the + Identifier-Locator Network Protocol (ILNP)", RFC 6746, + November 2012. + + [RFC6747] Atkinson, R. and S. Bhatti, "Address Resolution Protocol + (ARP) Extension for the Identifier-Locator Network + Protocol for IPv4 (ILNPv4)", RFC 6747, November 2012. + +15.2. Informative References + + [BA11] Bhatti, S. and R. Atkinson, "Reducing DNS Caching", + Proceedings of IEEE Global Internet Symposium (GI2011), + Shanghai, P.R. China, 15 April 2011. + + [BAK11] Bhatti, S.N., Atkinson, R., and J. Klemets, "Integrating + Challenged Networks", Proceedings of IEEE Military + Communications Conference (MILCOM), IEEE, Baltimore, MD, + USA, Nov 2011. + + [LA06] Liu, C. and P. Albitz, "DNS and Bind", 5th Edition, + O'Reilly & Associates, Sebastopol, CA, USA, 2006. ISBN + 0-596-10057-4. + + [PHG02] Pappas, A., Hailes, S. and R. Giaffreda, "Mobile Host + Location Tracking through DNS", Proceedings of IEEE + London Communications Symposium, IEEE, September 2002, + London, England, UK. + + [SBK02] Snoeren, A., Balakrishnan, H. and M. Frans Kaashoek, + "Reconsidering Internet Mobility", Proceedings of 8th + Workshop on Hot Topics in Operating Systems, IEEE, + Elmau, Germany, May 2001. + + + + +Atkinson & Bhatti Experimental [Page 36] + +RFC 6741 ILNP Engineering November 2012 + + + [REFERRAL] Carpenter, B., Boucadair, M., Halpern, J., Jiang, S., + and K. Moore, "A Generic Referral Object for Internet + Entities", Work in Progress, October 2009. + + [RFC826] Plummer, D., "Ethernet Address Resolution Protocol: Or + Converting Network Protocol Addresses to 48.bit Ethernet + Address for Transmission on Ethernet Hardware", STD 37, + RFC 826, November 1982. + + [RFC3972] Aura, T., "Cryptographically Generated Addresses (CGA)", + RFC 3972, March 2005. + + [RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing + Architecture", RFC 4291, February 2006. + + [RFC4581] Bagnulo, M. and J. Arkko, "Cryptographically Generated + Addresses (CGA) Extension Field Format", RFC 4581, + October 2006. + + [RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy + Extensions for Stateless Address Autoconfiguration in + IPv6", RFC 4941, September 2007. + + [RFC4982] Bagnulo, M. and J. Arkko, "Support for Multiple Hash + Algorithms in Cryptographically Generated Addresses + (CGAs)", RFC 4982, July 2007. + + [RFC5534] Arkko, J. and I. van Beijnum, "Failure Detection and + Locator Pair Exploration Protocol for IPv6 Multihoming", + RFC 5534, June 2009. + + [RFC6164] Kohno, M., Nitzan, B., Bush, R., Matsuzaki, Y., Colitti, + L., and T. Narten, "Using 127-Bit IPv6 Prefixes on + Inter-Router Links", RFC 6164, April 2011. + + [RFC6748] Atkinson, R. and S. Bhatti, "Optional Advanced + Deployment Scenarios for the Identifier-Locator Network + Protocol (ILNP)", RFC 6748, November 2012. + + + + + + + + + + + + + +Atkinson & Bhatti Experimental [Page 37] + +RFC 6741 ILNP Engineering November 2012 + + +16. Acknowledgements + + Steve Blake, Stephane Bortzmeyer, Mohamed Boucadair, Noel Chiappa, + Wes George, Steve Hailes, Joel Halpern, Mark Handley, Volker Hilt, + Paul Jakma, Dae-Young Kim, Tony Li, Yakov Rehkter, Bruce Simpson, + Robin Whittle and John Wroclawski (in alphabetical order) provided + review and feedback on earlier versions of this document. Steve + Blake provided an especially thorough review of an early version of + the entire ILNP document set, which was extremely helpful. We also + wish to thank the anonymous reviewers of the various ILNP papers for + their feedback. + + Roy Arends provided expert guidance on technical and procedural + aspects of DNS issues. + +Authors' Addresses + + RJ Atkinson + Consultant + San Jose, CA 95125 + USA + + EMail: rja.lists@gmail.com + + + SN Bhatti + School of Computer Science + University of St Andrews + North Haugh, St Andrews + Fife KY16 9SX + Scotland, UK + + EMail: saleem@cs.st-andrews.ac.uk + + + + + + + + + + + + + + + + + + +Atkinson & Bhatti Experimental [Page 38] + |