You have been asked to come up with a subnet mask that will allow all three web servers to be on the same network while providing the max number of subnets.Which network address and subnet mask meet this requirement?（）

单项选择题Which command displays the CHAP authentication process as it occurs between two routers?（）

A. debug authentication
B. debug chap ppp
C. debug chap authentication
D. debug ppp authentication

单项选择题At which layer of the OSI model dose PPP perform?（）

A. Layer 3
B. Layer 4
C. Layer 2
D. Layer 5

单项选择题Which command is used to display the collection of OSPF link states?（）

A. show ip ospf lsa database
B. show ip ospf link-state
C. show ip ospf neighbors
D. show ip ospf database

单项选择题When you are troubleshooting an ACL issue on a router,which command can help you to verify which interfaces are affected by the ACL?（）

A. show ip access-list
B. show access-list
C. list ip interface
D. show interface
E. show ip interface

单项选择题Three switches are connected to one anther via trunk ports.Assuming the default switch configuration,which switch is elected as the root bridge for the spanning-tree instance of vlan 1?（）

A. the switch with the lowest MAC address
B. the switch with the higest MAC address
C. the switch witch the higest IP address
D. the switch with the lowest IP address