1. [单选题]以下特殊区域中哪一个没有自动下发缺省路由（）
A. 末梢区域
B. 完全末梢区域
C. NSSA区域
D. 完全NSSA区域
2. [单选题]OSI七层模型中，网络层的数据封装名称为（）
A. 比特
B. 帧
C. 包
D. 段
3. [多选题]As the Ezonexam network administrator, you are required to have a firm understanding of the OSI model. Why does the data communication industry use the layered OSI reference model? (Choose two)
A. It enables equipment from different vendors to use the same electronic components, thus saving research and development funds
B. It encourages industry standardization by defining what functions occur at each layer of the model
C. It divides the network communication process into smaller and simpler components; thus aiding component development, design and troubleshooting
D. It provides a means by which changes in functionality in one layer require changes in other layers
E. It supports the evolution of multiple competing standards and thus provides business opportunities for equipment manufacturers
4. [单选题]如果网络中的路由器都是cisco路由器，则优先选择哪一个路由协议（）
A. RIP
B. EIGRP
C. IGRP
D. OSPF
5. [单选题]对交换机的描述，正确的是（）
A. 单广播域，单冲突域的设备
B. 单广播域，多冲突域的设备
C. 多广播域，单冲突域的设备
D. 多广播域，多冲突域的设备
