H3C Technologies H3C S12500 Series Switches - Manual (Page 149)

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• The loopback address is 0:0:0:0:0:0:0:1 (or ::1). It might never be assigned to any physical
interface and can be used by a node to send an IPv6 packet to itself in the same way as the
loopback address in IPv4.
• The unspecified address is 0:0:0:0:0:0:0:0 (or ::). It cannot be assigned to any node. Before
acquiring a valid IPv6 address, a node fills this address in the source address field of IPv6 packets.
The unspecified address cannot be used as a destination IPv6 address.
Multicast addresses
IPv6 multicast addresses listed in Table 8 are reserved for special purposes.
Table 8 Reserved IPv6 multicast addresses
Address Application
FF01::1 Node-local scope all-nodes multicast address
FF02::1 Link-local scope all-nodes multicast address
FF01::2 Node-local scope all-routers multicast address
FF02::2 Link-local scope all-routers multicast address
FF05::2 Site-local scope all-routers multicast address
Multicast addresses also include solicited-node addresses. A node uses a solicited-node multicast
address to acquire the link-layer address of a neighboring node on the same link and to detect duplicate
addresses. Each IPv6 unicast or anycast address has a corresponding solicited-node address. The format
of a solicited-node multicast address is:
FF02:0:0:0:0:1:FFXX:XXXX
Where FF02:0:0:0:0:1:FF is fixed and consists of 104 bits, and XX:XXXX is the last 24 bits of an IPv6
unicast address or anycast address.
EUI-64 address-based interface identifiers
An interface identifier is 64 bits and uniquely identifies an interface on a link.
Various types of interfaces generate EUI-64 address-based interface identifiers in different ways.
• On an IEEE 802 interfaces (such as an Ethernet interface and a VLAN interface)
The interface identifier is derived from the link-layer address (typically a MAC address) of the
interface. To expand the 48-bit MAC address to a 64-bit interface identifier, the hexadecimal
number FFFE (16 bits of 1111111111111110) is inserted into the MAC address (behind the 24th
high-order bit). To make sure the obtained interface identifier is unique, the universal/local (U/L)
bit (which is the seventh high-order bit) is set to 1. Thus, an EUI-64 address-based interface
identifier is obtained.
Figure 58 shows the process of how an EUI-64 address-based interface identifier is generated
from a MAC address.