H3C Technologies H3C S12500 Series Switches - Manual (Page 123)

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of all transition technologies. However, it does not solve the IPv4 address depletion issue because each
dual stack node must have a globally unique IPv4 address.
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Tunneling
Tunneling uses one network protocol to encapsulate the packets of another network protocol and
transfers them over the network. For more information about tunneling, see "Configuring tunneling."
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NAT-PT
Network Address Translation – Protocol Translation (NAT-PT) enables communication between IPv4 and
IPv6 nodes by translating between IPv4 and IPv6 packets. It performs IP address translation, and
according to different protocols, performs semantic translation for packets. This technology is only
suitable for communication between a pure IPv4 node and a pure IPv6 node. For more information about
NAT-PT, see "Configuring NAT-PT."
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6PE
6PE enables communication between isolated IPv6 networks over an IPv4 backbone network.
6PE adds labels to the IPv6 routing information about customer networks and advertises the information
into the IPv4 backbone network over internal Border Gateway Protocol (IBGP) sessions. IPv6 packets are
labeled and forwarded over tunnels on the backbone network. The tunnels can be GRE tunnels or MPLS
LSPs.
Figure 46 Network diagram
6PE is a highly-efficient solution. When an ISP wants to utilize the existing IPv4/MPLS network to provide
IPv6 traffic switching, it only needs to upgrade the PE routers. In addition, the operation risk of 6PE is very
low. For more information about 6PE, see Layer 3—IP Routing Configuration Guide.
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Protocols and standards
Protocols and standards related to IPv6 include:
• RFC 1881, IPv6 Address Allocation Management
• RFC 1887, An Architecture for IPv6 Unicast Address Allocation
• RFC 1981, Path MTU Discovery for IP version 6
• RFC 2375, IPv6 Multicast Address Assignments
• RFC 2460, Internet Protocol, Version 6 (IPv6) Specification
• RFC 2463, Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6)
Specification