单项选择题
A.8 subnets, 31 hosts
B.8 subnets, 32 hosts
C.16 subnets, 30 hosts
D.16 subnets, 32 hosts
E.A Class B address can't be subnetted into the fourth octet.
单项选择题 As a network administrator，you have been instructed to prevent all traffic or iginating on the LAN from entering the R2 router.Which the following command would implement the access list on the interface of theR2 router？（）
单项选择题 S0/0 on R1 is configured as a multipoint interface to communicate with R2 and R3 in the hub-and-spoke Frame Relay topology shown in the exhibit. Originally, static routes were configured between these routers to successfully route traffic between the attached networks. What will need to be done in order to use RIPv2 in place of the static routes?（）
单项选择题 为了允许建立一个TELNET会话，以下哪个命令集必须被配置？（）