1. [单选题]Your network uses the172.12.0.0 class B address. You need to support 459 hosts per subnet, while accommodating the maximum number of subnets. Which mask would you use?
A. 255.255.0.0.
B. 255.255.128.0.
C. 255.255.224.0.
D. 255.255.254.0.
E. None of the above
2. [多选题]When you compare the differences between half-duplex and full-duplex Ethernet, which of the following characteristics are exclusive to half-duplex? (Select two answer choices)
A. Half-duplex Ethernet operates in a shared collision domain.
B. Half-duplex Ethernet operates in an exclusive broadcast domain.
C. Half-duplex Ethernet has efficient throughput.
D. Half-duplex Ethernet has lower effective throughput.
E. Half-duplex Ethernet operates in an exclusive collision domain.
3. [单选题]“ipaccess-group”命令在接口上缺省的应用方向是什么(what is)"（）。
A. in
B. 具体取决于接口应用哪个访问控制列表
C. out
D. 无缺省值
4. [单选题]You need to decide on which trunking method to implement in the Ezonexam network. What is a characteristic of ISL and 802.1q frame. tagging in a switched LAN environment?
A. They are used to find the best path through a network.
B. They allow the exchange of filtering tables.
C. They specify different implementations of the Spanning-Tree Protocol.
D. They allow the exchange of routing tables
E. They provide inter-switch VLAN communication.
5. [单选题]路由器上，清空路由表的命令是（）
A. clear ip
B. delete ip route
C. delete route
D. clearip route*
