问题 单项选择题

下列对IPv6地址FF60:0:0:0601:BC:0:0:05D7的简化表示中,错误的是______。

A.FF60::601:BC:0:0:05D7
B.FF60::601:BC::05D7
C.FF60:0:0:601:BC::05D7
D.FF60:0:0:0601:BC::05D7

答案

参考答案:B

解析: RFC2373对IPv6地址空间结构与地址基本表示方法进行了定义。IPv6的128位地址按每 16位划分为1个位段,每个位段被转换为1个4位的十六进制数,并用冒号“:”隔开,这种表示法称为冒号十六进制表示法。
一个IPv6地址中可能会出现多个二进制数0,因此规定了“零压缩法”,通过压缩某个位段中的前导 0来简化IPv6地址的表示。例如,“0601”可以简写为“601”。但是在使用零压缩法时,不能把一个位段内部的有效0也压缩掉。例如“FF60”不能简写为“FF6”。需要注意的是,每个位段至少应该有1个数字,如“0000”可以简写为“0”。
如果IPv6地址中包含了一长串0,则可以使用“双冒号表示法”,进一步简化IP地址表达。例如,“FF60:0:0:0601:BC:0:0:05D7”可以简化为“FF60::601:BC:0:0:5D7”,或者是“FF60::601:BC:0:0:05D7”,或者是“FF60:0:0:601:BC::05D7”,再或者是“FF60:0:0:0601:BC::05D7”等。需要注意的是,双冒号“::”在一个IPv6地址中只能出现一次。例如,“FF60:0:0:0601:BC:0:0:05D7”不能简化为“FF60::601:BC::05D7”形式。

单项选择题

Information systems design is defined as those tasks that focus on the specification of a detailed computer-based solution. Typically, there are four systems design tasks for in-house development.

1) The first task is to specify(),which defines the technologies to be used by one, more, or all information systems in terms of their data, processes, interfaces, and network components. This task is accomplished by analyzing the data models and process models that are initially created during requirements analys16.

2) The next systems design task is to develop the (). The purpose of this task is to prepare technical design specifications for a database that will be adaptable to future requirements and expansion.

3) Once the database prototype has been built, the systems designer can work closely with system users to develop input, output and dialogue specifications. The()must be specified to ensure that the outputs are not lost, misrouted, misused, or incomplete.

4) The fourth design task involves packaging all the specifications from the previous design tasks into a set of specifications that will guide the() activities during the following phases of the systems development methodology.

Finally, we should() and update the project plan accordingly. The key deliverable should include a detailed plan for the construction phase that should follow

The()must be specified to ensure that the outputs are not lost, misrouted, misused, or incomplete.

A.format and layout

B.transaction details

C.additional instructions

D.internal controls

单项选择题