6 to4/6in4 tunnel of IPv4 to IPv6 transition Solution

Although the entire IPv4 infrastructure is still the foundation, IPv6 can be deployed on the infrastructure through tunneling. You can use tunnels to encapsulate IPv6 services in IPv4 packets and then transmit IPv6 services through IPv4 routing infrastructure. For example, IPv6 EDGE networks can be interconnected without upgrading the IPv4 core network. An IPv6 tunnel can be configured between two edge routers or between routers and hosts. However, nodes at both ends of the tunnel must support both IPv4 and IPv6 protocol stacks.

There are two common IPv6 tunnel modes: 6in4 tunnel and 6to4 tunnel.

6to4 tunnel

The 6to4 tunnel allows the local IPv6 network to connect to the remote IPv6 network through the IPv4 network. The main difference between the 6to4 tunnel and the 6in4 tunnel is that the 6to4 tunnel is not point-to-point, but point-to-point. In the 6to4 tunnel, the IPv4 network is regarded as a virtual NBMA network, so the router is not configured in pairs. You can find the other end of the tunnel by embedding the IPv4 address of the IPv6 address.

The VBR of the IPv6 EDGE network can create a 6to4 tunnel to the peer IPv6 network based on each packet. The IPv6 address of the VBR is prefixed with 2002:/16. Its format is shown in. This type of IPv6 address is short for 6to4.

The IPv4 address is the only IPv4 address in the world. You must configure the IPv4 address on the physical interface connecting the VBR to the IPv4 network. The length of the network identifier is 16 bits for addressing the edge network. The routers or hosts at both ends of the tunnel must support IPv4 and IPv6 protocol stacks. The following describes the workflow of the 6to4 tunnel.

As shown in, R1 and R2 are the two ends of the 6to4 tunnel. The host in R1 and site 1 is configured with the 6to4 address, the IPv4 address embedded in the 6to4 address is the IPv4 address that R1 connects to the IPv4 network.

Both the R2 and Site 2 hosts are configured with the 6to4 address. The IPv4 address embedded in the 6to4 address is the IPv4 address of R2 to connect to the IPv4 network.

When the host of Site 1 accesses the host of Site 2, IPv6 packets are sent to the gateway R1, and R1 displays the destination address of the message, which is 6to4, you can obtain the IPv4 address of the Liu Yi end of the 6to4 tunnel from the 6to4 address. Therefore, R1 encapsulates IPv6 packets in IPv4 packets. The destination address of IPv4 packets is the IPv4 address of the Peer tunnel, and the source address is the IPv4 address of the local tunnel. The packet is forwarded to R2. R2 performs the unencapsulate operation and sends the IPv6 packet to the target host.

6in4 Tunnel

The 6in4 tunnel establishes a permanent link between two IPv6 networks through an IPv4 network to provide stable connections for the IPv6 networks at both ends of the tunnel. You can manually configure the IPv6 address, tunnel source IPv4 address, and tunnel destination IPv4 address on the tunnel interface. The routers or hosts at both ends of the tunnel must support IPv4 and IPv6 protocol stacks.