Intra-Site Automatic Tunnel Addressing Protocol (ISATAP)

RFC 4214

The Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) connects IPv6 hosts/routers over IPv4 networks.  ISATAP views the IPv4 network as a link layer for IPv6 and views other nodes on the network as potential IPv6 hosts/routers.  ISATAP supports an automatic tunneling abstraction similar to the Non-Broadcast Multiple Access (NBMA) model.