System information

Configuring the Switch
3-20
3
• EUI-64 (Extended Universal Identifier) – Configures an IPv6 address for an
interface using an EUI-64 interface ID in the low order 64 bits.
- When using EUI-64 format for the low-order 64 bits in the host portion of the
address, the value entered in the IPv6 Address field includes the network
portion of the address, and the value in the Prefix Length field indicates how
many contiguous bits (from the left) of the address comprise the prefix (i.e.,
the network portion of the address). Note that the value specified in the IPv6
Address field may include some of the high-order host bits if the specified
prefix length is less than 64 bits. If the specified prefix length exceeds 64
bits, then the bits used in the network portion of the address will take
precedence over the interface identifier.
- IPv6 addresses are 16 bytes long, of which the bottom 8 bytes typically form
a unique host identifier based on the device’s MAC address. The EUI-64
specification is designed for devices that use an extended 8-byte MAC
address. For devices that still use a 6-byte MAC address (also known as
EUI-48 format), it must be converted into EUI-64 format by inverting the
universal/local bit in the address and inserting the hexadecimal number
FFFE between the upper and lower three bytes of the MAC address.
For example, if a device had an EUI-48 address of 28-9F-18-1C-82-35, the
global/local bit must first be inverted to meet EUI-64 requirements (i.e., 1 for
globally defined addresses and 0 for locally defined addresses), changing
28 to 2A. Then the two bytes FFFE are inserted between the OUI (i.e.,
organizationally unique identifier, or company identifier) and the rest of the
address, resulting in a modified EUI-64 interface identifier of
2A-9F-18-FF-FE-1C-82-35.
- This host addressing method allows the same interface identifier to be used
on multiple IP interfaces of a single device, as long as those interfaces are
attached to different subnets.
• Global – Configures an IPv6 global unicast address based on values entered
in the IPv6 Address and Prefix Length fields.
- Auto Detect – System will automatically detect the address type according to
the address/prefix entered in the IPv6 Address field.
Current Address Table
• IPv6 Address – IPv6 address assigned to this interface.
In addition to the unicast addresses assigned to an interface, a node is required to
join the all-nodes multicast addresses FF01::1 and FF02::1 for all IPv6 nodes
within scope 1 (interface-local) and scope 2 (link-local), respectively.
FF01::1/16 is the transient node-local multicast address for all attached IPv6
nodes, and FF02::1/16 is the link-local multicast address for all attached IPv6
nodes. The node-local multicast address is only used for loopback transmission of
multicast traffic. Link-local multicast addresses cover the same types as used by
link-local unicast addresses, including all nodes (FF02::1), all routers (FF02::2),
and solicited nodes (FF02::1:FFXX:XXXX) as described below.