Figure 1 shows the router solicitation process by displaying a computer sending a request for IPv6 addressing information from all IPv6 routers.  The figure also shows a router advertisement message being sent by a router.  This message can have one of three options configured, option one gives all the necessary addressing information, option two sets some addressing options but relies on a DHCPv6 server for some settings, and option three relies solely on a DHCPv6 server for all addressing information.  The router advertisement in the figure is using option one and it is telling the computer the prefix, prefix-length, and default gateway to use. Figure 2 shows an example of SLAAC. A computer uses the IPv6 global unicast of the router to construct its own global unicast  address. The computer uses the prefix from the router's address, which is 2001:DB8:ACAD:1 in the example. And then the computer either uses EUI-64 or generates a random 64-bit number to fill in the interface ID portion of the address.