Ipv6 Over Ipv4 Tunnel - 3Com MSR 50 Series Configuration Manual

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IPv6 over IPv4 Tunnel

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ONFIGURATION
solutions are available. With their own characteristics, they are used to solve
communication problems in different transition stages under different
environments.
Currently, there are three major transition technologies: dual stack (RFC2893),
tunneling (RFC2893), and NAT-PT (RFC2766).
Tunneling is an encapsulation technology, which utilizes one network transport
protocol to encapsulate packets of another network transport protocol and
transfer them over the network. A tunnel is a virtual point-to-point connection. In
practice, a tunnel interface can be considered as a virtual interface that supports
only point-to-point connection. One tunnel provides one channel to transfer
encapsulated packets. Packets can be encapsulated and decapsulated at both
ends of a tunnel. Tunneling refers to the whole process from data encapsulation to
data transfer to data decapsulation.
For related configuration about the dual protocol stack, refer to
■
Configuration" on page
For related configuration about NAT-PT, refer to
■
681.
In addition, the device supports IPv6 on the provider edge routers (6PE) - a
■
transition technology.
Principle
The IPv6 over IPv4 tunneling mechanism encapsulates an IPv4 header in IPv6 data
packets so that IPv6 packets can pass an IPv4 network through a tunnel to realize
interworking between isolated IPv6 networks, as shown in
CAUTION: The devices at both ends of an IPv6 over IPv4 tunnel must support
IPv4/IPv6 dual stack.
Figure 205 Principle of IPv6 over IPv4 tunnel
IPv 6 header IPv 6 data
IPv 6 network
Dual stack router
IPv 6 host
The IPv6 over IPv4 tunnel processes packets in the following way:
1 A host in the IPv6 network sends an IPv6 packet to the device at the source end of
the tunnel.
2 After determining according to the routing table that the packet needs to be
forwarded through the tunnel, the device at the source end of the tunnel
691.
IPv 4 header IPv 6 header
IPv 4 network
IPv 6 over IPv 4 tunnel
"Dual Stack
"Configuring NAT-PT" on page
Figure 205.
IPv 6 data
IPv 6 header
IPv 6 network
Dual stack router
IPv 6 host
IPv 6 data