The Shim6 architecture for IPv6 multihoming

The Shim6 architecture enables IPv6 multihoming without compromising the scalability of the global routing system by using provider aggregatable addresses. To do so, hosts use different addresses as locators for data packet transmission, but present the same source and destination identifier pair to transport and upper layers. The components of this architecture are the Shim6 entity, which maps and translates upper-layer identifiers and locators for remote hosts; the Shim6 protocol, which exchanges mapping information between two hosts that communicate; and the REAP protocol, which monitors the existing unidirectional paths and finds new valid locator combinations in case of failure. To protect against new vulnerabilities this architecture may introduce compared to IPv6, Shim6 hosts use either cryptographically generated addresses or hash-based addresses.