from Wikipedia, the free encyclopedia
IPv6 transition mechanisms
4in6 Tunneling from IPv4 to IPv6
6in4 Tunneling from IPv6 to IPv4
6over4 Transport of IPv6 data packets between dual-stack nodes over an IPv4 network
6to4 Transport of IPv6 data packets over an IPv4 network (obsolete)
AYIYA Anything In Anything
Dual stack Network nodes with IPv4 and IPv6 in parallel operation
Dual-Stack Lite (DS-Lite) Like dual stack, but with global IPv6 and carrier NAT IPv4
6rd IPv6 rapid deployment
ISATAP Intra-Site Automatic Tunnel Addressing Protocol (deprecated)
Teredo Encapsulation of IPv6 packets in IPv4 UDP -Datenpaketen
NAT64 Translation of IPv4 addresses into IPv6 addresses
464XLAT Translation from IPv4 to IPv6 to IPv4 addresses
SIIT Stateless IP / ICMP translation

6over4 , also known as “ IPv6 over IPv4 ”, is an IPv6 transition mechanism for the transport of IPv6 data packets between dual-stack nodes that are connected via an IPv4 network. This mechanism requires an IPv4 multicast infrastructure.


With 6over4, a link-local IPv6 address is generated from an IPv4 address . To do this, the IPv4 address is fe80::preceded by the character string .

The following algorithm is used to generate the address :


The interface identifier is formed as follows:



The link-local address is derived from the IPv4 address:

fe80:0000:0000:0000:0000:0000: respectively

fe80:0000:0000:0000:0000:0000:5BC6:AEE1 or short: fe80::5BC6:AEE1

A special mechanism enables Neighbor Discovery for IPv4. From the perspective of the IPv4 nodes, the IPv6 infrastructure is used as a link layer (security layer in the OSI model ).

Compared to other IPv6 transition mechanisms, 6over4 is rarely used. The tunneling method used can cause throughput problems in the network and offers less security for data transmission than other methods.


  • RFC 2529 , Transmission of IPv6 over IPv4 Domains without Explicit Tunnels (March 1999)

Individual evidence

  1. 2529, Transmission of IPv6 over IPv4 Domains without Explicit Tunnels , Section 1.
  2. cf. Franz-Joachim Kauffels: Fundamentals of network technology, Heidelberg, mitp 2007, ISBN 978-3-8252-8377-3 , p. 327
  3. cf. 6over4