Stateless Address Autoconfiguration

Correct Answer: Generating a link-local address

In an IPv6 network, the first step in the Stateless Address Autoconfiguration process is generating a link-local address. This address, which is not globally unique, is used for communication within a network segment. This is the correct answer because it is the first action a device will take when using Stateless Address Autoconfiguration. On the other hand, contacting a DHCP server is usually not needed in Stateless Address Autoconfiguration because the address configuration is done without a centralized server. Generating a global unicast address is an eventual step, not the first one, in the Stateless Address Autoconfiguration process. Similarly, obtaining a unique local address is not the initial step in Stateless Address Autoconfiguration since these addresses are designed for local networking and can be manually or automatically configured, but this is not necessarily the first action that a device will take.

Correct Answer: Duplicate Address Detection (DAD)

The best method to resolve the issue of duplicate IP addresses in an IPv6 network using Stateless Address Autoconfiguration (SLAAC) is Duplicate Address Detection (DAD). The DAD process involves a device sending a Neighbor Solicitation message and if a Neighbor Advertisement message is received in response, it means the IP address is already in use and a duplicate, hence it's not bound to the interface. This process helps to quickly detect duplicates and prevent IP address conflicts on the network. The other options listed are not specifically designed to detect duplicate IP addresses. The Neighbor Discovery Protocol is for maintaining and discovering other IPv6 nodes on the network, Router Advertisement is a type of ICMPv6 message that routers use to distribute network configuration parameters, and Soliciting Node Multicast refers to a special type of IP multicast group that nodes join to receive specific information.

Correct Answer: Stateless Address Autoconfiguration (SLAAC)

The Stateless Address Autoconfiguration (SLAAC) is the correct method to automatically assign IPv6 addresses to devices in a medium-sized business network. SLAAC is a method in which the device uses inherent IPv6 network capabilities to generate its own IP address using a combination of locally available information and information advertised by routers. This removes the need for manual configuration or DHCP servers. On the other hand, Dynamic Host Configuration Protocol (DHCP) can also be used but it is not the most optimal solution as it may require a bit more setup and administration compared to SLAAC. Manual configuration is not a method to automatically assign IPv6 addresses, it is a manual task. Lastly, IPv4 to IPv6 tunneling is a mechanism to encapsulate IPv6 packets within IPv4 packets, but it doesn't assign IPv6 addresses.