Which PPP subprotocol negotiates authentication options?（）

多项选择题A network administrator issues the ping 192.168.2.5 command and successfully tests connectivity to a host that has been newly connected to the network. Which protocols were used during the test?（）

A. ARP
B. CDP
C. DHCP
D. DNS
E. ICMP

单项选择题What is the purpose of Spanning Tree Protocol?（）

A. to prevent routing loops
B. to create a default route
C. to provide multiple gateways for hosts
D. to maintain a loop-free Layer 2 network topology
E. to enhance the functions of SNMP

单项选择题What is the function of the CSMA CD algorithm in Ethernet technologies?（）

A. defines how the media is accessed
B. supplies a token to determine which host has access to the media
C. defines the encoding of electrical signals on the wire
D. determines the preamble bits

单项选择题What value is primarily used to determine which port becomes the root port on each non root switch in a spanning-tree topology?（）

A. path cost
B. lowest port MAC address
C. VTP revision number
D. highest port priority number
E. port priority number and MAC address

单项选择题What is the purpose of the OSPF router ID in a OR BOR election?（）

A. It is used with the OSPF priority values to determine which OSPF router will become the DR or BOR in a point-to-point network
B. It is used with the OSPF priority values to determine which interface will be used to form a neighbor relationship with another OSPF router
C. It is used with the OSPF priority values to determine which router will become the DR or BOR in a multi access network
D. It is used to determine which interfaces will send Hello packets to neighboring OSPF routers