H3C Technologies H3C S12500-X Series Switches - Manual (Page 125)

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Redirection
Upon receiving a packet from a host, the gateway sends an ICMPv6 Redirect message to inform a better
next hop to the host when the following conditions are met (similar to the ICMP redirection function in
IPv4):
• The interface receiving the packet is the same as the interface forwarding the packet.
• The selected route is not created or modified by an ICMPv6 Redirect message.
• The selected route is not a default route on the device.
• The forwarded IPv6 packet does not contain the routing extension header.
IPv6 transition technologies
IPv6 transition technologies enable communication between IPv4 and IPv6 networks. Several IPv6
transition technologies can be used in different environments and periods.
Dual stack
Dual stack is the most direct transition approach. A network node that supports both IPv4 and IPv6 is a
dual-stack node. A dual-stack node configured with an IPv4 address and an IPv6 address can forward
both IPv4 and IPv6 packets. An application that supports both IPv4 and IPv6 prefers IPv6 at the network
layer. Dual stack is suitable for communication between IPv4 nodes or between IPv6 nodes. It is the basis
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.
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 ."
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
• RFC 2464, Transmission of IPv6 Packets over Ethernet Networks
• RFC 2526, Reserved IPv6 Subnet Anycast Addresses
• RFC 3307, Allocation Guidelines for IPv6 Multicast Addresses
• RFC 3513, Internet Protocol Version 6 (IPv6) Addressing Architecture
• RFC 4191, Default Router Preferences and More-Specific Routes