单项选择题
The network administrator has discovered that the power supply has failed on a switch in the company LAN and that the switch has stopped functioning. It has been replaced with a Cisco Catalyst 2950 series switch.What must be done to ensure that this new switch becomes the root bridge on the network?（）
A.One router is running RIPv1. B.RIP neighbor is 224.0.0.9. C.The network contains a loop. D.Network 10.10.1.0 is reachable.
单项选择题 Which IPsec security protocol should be used when confidentiality is required？（）
多项选择题 Which two subnetworks would be included in the summarized address of 172.31.80.0 /20? （）
单项选择题 Which command can you use to manually assign a static IPV6 address to a router interface？（）
