Chapter 33 IPv6 Commands
Ethernet Switch CLI Reference Guide
142
Unspecified
An unspecified address (0:0:0:0:0:0:0:0 or ::) is used as the source address when a device does
not have its own address. It is similiar to “0.0.0.0” in IPv4.
EUI-64
The EUI-64 (Extended Unique Identifier) defined by the IEEE (Institute of Electrical and
Electronics Engineers) is an interface ID format designed to adapt with IPv6. It is derived from
the 48-bit (6-byte) Ethernet MAC address as shown next. EUI-64 inserts the hex digits fffe
between the third and fourth bytes of the MAC address and complements the seventh bit of the
first byte of the MAC address. See the following example.
Stateless Autoconfiguration
With stateless autoconfiguration in IPv6, addresses can be uniquely and automatically
generated. Unlike DHCPv6 (Dynamic Host Configuration Protocol version six) which is used
in IPv6 stateful autoconfiguration, the owner and status of addresses don’t need to be
maintained by a DHCP server. Every IPv6 device is able to generate its own and unique IP
address automatically when IPv6 is initiated on its interface. It combines the prefix and the
interface ID (generated from its own Ethernet MAC address, see Interface ID and EUI-64) to
form a complete IPv6 address.
When IPv6 is enabled on a device, its interface automatically generates a link-local address
(beginning with fe80).
When the interface is connected to a network with a router and the ipv6 address
autoconfig command is issued on the Switch, it generates
1
another address which
combines its interface ID and global and subnet information advertised from the router. This is
a routable global IP address.
DHCPv6
The Dynamic Host Configuration Protocol for IPv6 (DHCPv6, RFC 3315) is a server-client
protocol that allows a DHCP server to assign and pass IPv6 network addresses, prefixes and
other configuration information to DHCP clients. DHCPv6 servers and clients exchange
DHCP messages using UDP.
Each DHCP client and server has a unique DHCP Unique IDentifier (DUID), which is used
for identification when they are exchanging DHCPv6 messages. The DUID is generated from
the MAC address, time, vendor assigned ID and/or the vendor's private enterprise number
registered with the IANA. It should not change over time even after you reboot the device.
MAC
00 : 13 : 49 :12 : 34 :56
EUI-64
02 :13 :49 : FF : FE :12 : 34 :56
1. In IPv6, all network interfaces can be associated with several addresses.
To Next Page
Loading...
Need help?
General
