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. [单选题]The Ezonexam network administrator needs to a switch named VE1 to become the root bridge for a redundant path switched network. What can be done to ensure that VE1 will always assume the role as the root bridge?
A. Assign the switch a higher MAC address than the other switches in the network have
B. Establish a direct link from the switch to all other switches in the network
C. Configure the switch full-duplex operation and configure the other switches for half-duplex operation
D. Configure the switch so that it has lower priority than other switches in the network
E. None of the above
3. [单选题]IP地址为：192.168.50.70，掩码为：255.255.255.248，则该IP地址所在子网的子网号为（）
A. 192.168.50.32
B. 192.168.80.64
C. 192.168.50.96
D. 192.168.50.71
