指定した IPv6 プレフィックスとインターフェイスの MAC アドレスから IPv6 アドレスを自動的に生成するコマンドはどれですか?
正解:B
The correct command is ipv6 address 2001:DB8:5:112::/64 eui-64. The wording says the address is generated from a specified IPv6 prefix and the interface MAC address. That is exactly what the eui-64 keyword does: it derives the 64-bit interface identifier from the MAC address and combines it with the configured /64 prefix. The ipv6 address autoconfig command also can create an address, but it learns the prefix from Router Advertisement messages through SLAAC; the prefix is not explicitly specified in the command. DHCPv6 would request addressing information from a DHCPv6 server, and the link-local option shown is not a global unicast address built from the stated prefix. Cisco CCNA v1.1 Network Fundamentals includes IPv6 address types and address configuration methods, and this question tests precise IOS syntax. When the prefix is typed in the command and the MAC-derived interface ID is required, choose the static EUI-64 form, not autoconfig.