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IPv6 Advantages

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Local Network Addressing

To autoconfigure hosts on a local network, IPv6 uses each network device's hardware MAC address to generate a link-local temporary address by which hosts are queried and configured. The address is prefixed by FE80::0, followed by an interface identifier. A uniqueness test is then performed on the generated address using the Neighbor Discovery Protocol (NDP). It checks the other host's link-local addresses, and it remains unmatched assigns the valid Link-local address within the physical network. It connects hosts available on a small local network and cannot be routed to an extensive network.

This address is added to the local address, replacing the original link-local prefix giving a complete global Internet address, or in case of private networks, site-local addresses. The NDP, a duplicate address detection procedure, is used to query information before assigning it officially. Routers routinely advertise this address information, though they can be specifically requested.

For Linux system operating as router radvd (Router ADVertisement Daemon) is used for advertising addresses with IPv6 forwarding (Use sysctl and set net.ipv6.conf.all.forwarding to 1). It specifies the network prefix in the /etc/radvd.conf configuration file consisting of interface entries listing interface options, prefix definitions, and options along with router definitions.

The radvd daemon detects router network address requests from hosts as router solicitations and provides them with a network address using a router advertisement.

Router Renumbering Protocol

Renumbering used when a network changes ISP and requires the change in net addresses of all hosts. Example mobile networks, where hosts get plugged to different large-networks and thus require renumbering each time. The router assigns a time limit on addresses, specifying an expiration limit. At expiry, to ease transition interface still keeps old addresses as deprecated addresses, while the new one first being used as preferred addresses for new connections. In effect, a host has two addresses, one deprecated and one preferred.

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