单项选择题
Which of the following protocols can be used to retrieve system and network performance information from a router?（）
A.LDAP B.IMAP C.TFTP D.SNMP
单项选择题 Which of the following commands would allow a computer to acquire an IP address?（）
单项选择题 Interior gateway protocols are used for resolving routes:（）。
单项选择题 At which of the following layers does the UDP protocol operate?（）
