Which of the following would MOST likely be used to pun……

单项选择题In which of the following layers of the OSI model does the TCP protocol operate?（）

A.Session
B.Network
C.Data link
D.Transport

单项选择题Which of the following ports does POP3 services use, by default?（）

A.25
B.110
C.143
D.443

单项选择题A user took a laptop on vacation and made changes to the configuration in order to use the device at the hotel. The user can reach the Internet, but cannot access any internal network resources. Which of the following is the MOST likely reason?（）

A. Incorrect DNS
B. Incorrect subnet mask
C. Duplicate IP address
D. Incorrect SSID

单项选择题A technician is reporting wireless transmission speeds of 300Mbps. Which of the following wireless standards is being used?（）

A.802.11a
B.802.11b
C.802.11g
D.802.11n

单项选择题A new company has been given one public IP address. The company employs 200 users requiring Internet access from the headquarters. Which of the following can be implemented to provide Internet access for all the employees?（）

A. Multicasting
B. Proxy server
C. NAT
D. Subnetting