单选题 IPv6 has many new and different characteristics and functionality compared to IPv4. Which of the following is an incorrect functionality or characteristic of IPv6? i. IPv6 allows for nonscoped addresses, which enables an administrator to restrict specific addresses for specific servers or file and print sharing, for example. ii. IPv6 has IPSec integrated into the protocol stack, which provides application-based secure transmission and authentication, iii. IPv6 has more flexibility and routing capabilities compared to IPv4 and allows for Quality of Service (QoS) priority values to be assigned to timesensitive transmissions. iv. The protocol offers autoconfiguration, which makes administration much easier compared to IPv4, and it does not require network address translation (NAT) to extend its address space.
【正确答案】 B
【答案解析】解析：B正确。IPv6允许范围地址，即它允许管理员限制诸如特定服务器、文件和打印共享的特定地址。IPv6的协议栈里已经集成了可以提供端到端的安全传输和身份认证的IPSec。 A不正确。因为IPv6支持范围地址，即它允许管理员限制诸如特定服务器、文件和打印共享的特定地址。例如，IPv6具有更大的灵活性和路由能力，并允许为时间敏感的传输分配服务质量(OoS)优先级。 C不正确。因为IPv6具有更大的灵活性和更强的路由能力，并允许为时间敏感的传输分配服务质量(QoS)优先级。IPv6的协议栈里已经集成了可以提供端到端的安全传输和身份认证的IPSec。 D不正确。因为IPv6的协议栈里已经集成了可以提供端到端的安全传输和身份认证的IPSec。此协议提供了自动配置功能，使得对其的管理工作变得更加容易；并且该协议并不需要使用网络地址转换(NAT)来扩展地址空间。