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?（）

Which IPsec security protocol should be used when confidentiality is required?（）

A network administrator is trying to add a new router into an established OSPF network.The networks attached to the new router do not appear in the routing tables of the other OSPF routers.Given the information in the partial configuration shown below,what configuration error is causing this problem?（）Router(config)#router ospf 1Router(config-router)#network 10.0.0.0 255.0.0.0 area 0

At which layer of the OSI model is RSTP used to prevent loops?（）

Which command encrypts all plaintext passwords?（）

What is the subnetwork address for a host with the IP address 201.100.5.68/28?（）

What is the result of issuing the frame-relay map ip 192.168.1.2 202 broadcast command?（）

Which statement is true, as relates to classful or classless routing?（）

Which encapsulation type is a Frame Relay encapsulation type that is supported by Cisco routers?（）

Which cisco ios command can help to determine the timing of various debug events,relative to each other,when you are debugging a complicated router issue?（）