单项选择题
Which of the following ports should be allowed through a firewall for Telnet to function？（）
A.23 B.25 C.50 D.110
单项选择题 Which of the following expansion cards would be necessary to increase fault tolerance in a VoIP server?（）
单项选择题 WhichofthefollowingensurestheMOSTsecureaccesstoaserverroom？（）
单项选择题 WhichofthefollowingisanexampleofaprivateIPaddress？（）
