"Symbiosis rules" between IPv4 and IPv6"

We are no stranger to the proposal of tunneling technology. It is better to apply it to the intercommunication between IPv4 and IPv6. Tunnel technology plays an important role in this transitional period. Now let's take a look at the related terms and some standards for intercommunication and conversion.

What are the common technical standards for intercommunication between IPv4 and IPv6?

The transition from an existing network to an IPv6 network is technically mature and can be gradual. International Standardization Organization and many R & D institutions have developed a variety of interconnection and conversion mechanisms between IPv4 and IPv6. The following provides common technical standards for intercommunication between IPv4 and IPv6:

◆ 6to4: RFC 3056

◆ NAT-PTNetwork Address Translation-Protocol Translation): RFC 2766

◆ SIITStateless IP/ICMP Translation): RFC 2765

◆ Tunnel broker: RFC 3053

◆ 6over4: RFC 2529

◆ BISBump-In-the-Stack): RFC 2767

◆ BIABump-in-the-API): RFC 3338

◆ SOCKS-gateway: RFC 3089

◆ TCP/UDP-relay: RFC 3142

◆ D1_dual Stack Transition mechanic): draft-ietf-ngtrans-dstm-08.txt

◆ ISATAPIntra-Site Automatic Tunnel Addressing Protocol): draft-ietf-ngtrans-isatap-08.txt

What is a tunnel? What does "IPv6 over IPv4" mean?

Tunnel) refers to the encapsulation of one protocol header in another protocol header, so that one protocol can communicate through the encapsulation of another protocol. An IPv6 tunnel encapsulates an IPv6 Header in an IPv4 header so that an IPv6 packet can communicate over an IPv4 network.

Before IPv6 is fully implemented, some networks provide IPv6 support first, but these IPv6 networks are isolated by backbone networks running the IPv4 protocol. The "IPv6 over IPv4" Tunnel is used to connect these isolated IPv6 networks to achieve intercommunication between IPv4 and IPv6. Tunneling Technology is currently used in the International IPv6 test bed 6Bone. The tunneling technology can be used to connect local IPv6 networks through the existing Internet backbone network that runs the IPv4 protocol, that is, the tunnel. Therefore, it is the most easy-to-use technology in the early stage of IPv4 to IPv6 transition.

The advantage of tunneling technology lies in the transparency of tunnels. Communication between IPv6 hosts can ignore the existence of tunnels. tunnels only serve as physical channels. It does not need a large number of IPv6 dedicated router devices and dedicated links, which can significantly reduce investment. The disadvantage is that configuring an IPv6 Tunnel on an IPv4 network is troublesome, and the tunnel technology cannot implement communication between an IPv4 host and an IPv6 host.