Architecture

The SHIM6 architecture defines SHIM6 Failure Detection and Locator Pair Exploration functions. The first is used to detect outages through the path defined by the current locator pair for a communication. To achieve this, hints provided by upper protocols such as TCP

Transmission Control Protocol

The Transmission Control Protocol is one of the core protocols of the Internet Protocol Suite. TCP is one of the two original components of the suite, complementing the Internet Protocol , and therefore the entire suite is commonly referred to as TCP/IP...

 are used, or specific SHIM6 packet probes. The second function is used to determine valid locator pairs that could be used when an outage is detected.

The ability to change locators while a communication is being held introduces security problems, so mechanisms based on applying cryptography to the address generation process (Cryptographically Generated Addresses

Cryptographically Generated Addresses

A Cryptographically Generated Address is an Internet Protocol Version 6 address that has a host identifier computed from a cryptographic one-way hash function...

, CGA), or on bounding the addresses to the prefixes assigned to a host through a hash (Hash-based addresses, HBA) have been defined. These approaches are not feasible for IPv4 because of the short address length (32 bits).

An implementation of shim6 in the Linux kernel called LinShim6 is now available.

External links

• IETF SHIM6 Working Group status page
• SHIM6 IPv6 multihoming web page

See also

• Locator/Identifier Separation Protocol
  Locator/Identifier Separation Protocol
  LISP is a "map-and-encapsulate" protocol which is currently developed by the Internet Engineering Task Force LISP Working Group. The basic idea behind the separation is that the Internet architecture combines two functions, routing locators and identifiers in one number space: the IP address...