IPv6 Address Assignment

Correct Answer: /64

The most efficient IPv6 prefix to use when connecting 500 devices to a subnet is /64. IPv6 addresses are 128 bits long, and the /64 notation means that the first 64 bits are used for the network address, leaving the other 64 bits for host addresses. This allows for a huge number of unique host addresses well into the trillions, far more than enough for 500 devices. On the contrary, using a /56, /48, or /32 prefix would leave fewer bits for the network address and unnecessarily more bits for host addresses, which is inefficient given the requirement.

Correct Answer: 2001:0DB8:0001:0000:0211:22FF:FE33:4455

When generating an IPv6 address using EUI-64, the MAC address is split in half and 'FFFE' is inserted in the middle. The 7th bit of the first byte (which is the 'universe/local' bit) is complemented. The original MAC address is 00:11:22:33:44:55. Following the guidelines, the EUI-64 based part of the address becomes 0211:22FF:FE33:4455. The prefix provides the rest of the address which is 2001:0DB8:0001:0000. Combining them results in the IPv6 address: '2001:0DB8:0001:0000:0211:22FF:FE33:4455'. This is why the correct answer is '2001:0DB8:0001:0000:0211:22FF:FE33:4455'. The other answers are incorrect as they do not comply to the EUI-64 rule to flip the 7th bit, use the correct prefix, or correctly insert 'FFFE'.

Correct Answer: FF02::1:FF00:1

The correct answer is FF02::1:FF00:1. In IPv6, FF02::1:FF00:0/104 is the prefix used for solicited-node multicast addresses. The last 24 bits of the IPv6 address (2001:db8::1) are appended to the prefix to create the solicited-node multicast address. For the address 2001:db8::1, the last 24 bits are 0:0:1. The Concatenation of FF02::1:FF00:0/104 and 0:0:1 gives FF02::1:FF00:1. The other options, FF02::2:FF00:1, FF02::1:FF00:db8, and FF02::1:Fdb8:1, are not valid as they did not follow the process as described earlier nor the right format.