Stateless address autoconfiguration automates some of the network administrator's tasks.
Stateless address autoconfiguration is the process
that IPv6 nodes (hosts or routers) use to automatically configure IPv6 addresses
for interfaces. The node builds various IPv6 addresses by combining an address
prefix with either an identifier derived from the MAC address of the node
or a user-specified interface identifier. The prefixes include the link-local
prefix (fe80::/10) and prefixes of length 64 advertised by
local IPv6 routers (if any exist). 
The node performs duplicate address detection to verify the uniqueness of the address before assigning it to an interface. The node sends out a neighbor solicitation query to the new address and waits for a response. If the node does not receive a response, then the address is assumed to be unique. If the node receives a response in the form of a neighbor advertisement, the address is already in use. If a node determines that its tentative IPv6 address is not unique, then autoconfiguration stops and manual configuration of the interface is required.