Shim6

This document discusses some considerations on the applicability of the level 3 multihoming Shim protocol for IPv6 (Shim6) and associated support protocols and mechanisms to provide site multihoming capabilities in IPv6. This document is not an Internet Standards Track specification; it is published for informational purposes.

This document specifies sockets API extensions for the multihoming shim layer. The API aims to enable interactions between applications and the multihoming shim layer for advanced locator management, and access to information about failure detection and path exploration.

This document is based on an assumption that a multihomed host is equipped with a conceptual sub-layer (hereafter called "shim sub- layer") inside the IP layer that maintains mappings between identifiers and locators. Examples of the shim are Shim6 and the Host Identity Protocol (HIP). This document is not an Internet Standards Track specification; it is published for informational purposes.

This document defines extensions to the current sockets API for the Host Identity Protocol (HIP). The extensions focus on the use of public-key-based identifiers discovered via DNS resolution, but also define interfaces for manual bindings between Host Identity Tags (HITs) and locators. With the extensions, the application can also support more relaxed security models where communication can be non-HIP-based, according to local policies. The extensions in this document are experimental and provide basic tools for further experimentation with policies. This document defines an Experimental Protocol for the Internet community.

This document defines the Shim6 protocol, a layer 3 shim for providing locator agility below the transport protocols, so that multihoming can be provided for IPv6 with failover and load-sharing properties, without assuming that a multihomed site will have a provider-independent IPv6 address prefix announced in the global IPv6 routing table. The hosts in a site that has multiple provider- allocated IPv6 address prefixes will use the Shim6 protocol specified in this document to set up state with peer hosts so that the state can later be used to failover to a different locator pair, should the original one stop working. [STANDARDS-TRACK]

This document specifies how the level 3 multihoming Shim6 protocol (Shim6) detects failures between two communicating nodes. It also specifies an exploration protocol for switching to another pair of interfaces and/or addresses between the same nodes if a failure occurs and an operational pair can be found. [STANDARDS-TRACK]

This memo describes a mechanism to provide a secure binding between the multiple addresses with different prefixes available to a host within a multihomed site. This mechanism employs either Cryptographically Generated Addresses (CGAs) or a new variant of the same theme that uses the same format in the addresses. The main idea in the new variant is that information about the multiple prefixes is included within the addresses themselves. This is achieved by generating the interface identifiers of the addresses of a host as hashes of the available prefixes and a random number. Then, the multiple addresses are generated by prepending the different prefixes to the generated interface identifiers. The result is a set of addresses, called Hash-Based Addresses (HBAs), that are inherently bound to each other. [STANDARDS-TRACK]