Exam N10-008 topic 1 question 106 discussion

IPv6 networks use Stateless Address Auto Configuration (SLAAC) to assign IP addresses. With SLAAC, devices send the router a request for the network prefix, and the device then uses the prefix along with its own MAC address to create an IP address.

A. The network gateway is configured to send router advertisements. The network administrator should verify that the network gateway is configured to send router advertisements (RA) for SLAAC (Stateless Address Autoconfiguration) to work properly. RA's are used to advertise the network prefix and other information, such as the default gateway, to the hosts on the LAN. Without these advertisements, the hosts will not be able to autoconfigure their IP addresses. B. A DHCP server is present on the same broadcast domain as the clients. A DHCP server is not required for SLAAC to work. SLAAC uses the network prefix advertised by the router to generate an IP address for the host. DHCP is used for DHCPv4 only. C. The devices support dual stack on the network layer. It's not necessary that all devices should support dual stack on the network layer. They should support IPv6 stack on their own. D. The local gateway supports anycast routing. Anycast routing is a method of routing traffic to multiple devices with the same IP address, but it is not required for SLAAC to work.

The answer is C: that a DHCP server is present on the same broadcast domain and is giving out non-SLAAC IPv6 addresses. The network admin wants SLAAC but "the autoconfiguration of the IP address did not occur as expected." As he was expecting SLAAC addresses, IPv6 routable addresses would be an unexpected occurence.

SLAAC stands for "Stateless Address Autoconfiguration." It is a method used in IPv6 (Internet Protocol version 6) networks to automatically configure the network interfaces of devices with unique IPv6 addresses without the need for a dedicated DHCP (Dynamic Host Configuration Protocol) server.

Stateless address autoconfiguration (SLAAC) allows a host to autoconfigure an interface by listening for Router Advertisements to obtain a network prefix.