N10-004单项选择题每日一练(2018.08.12)

单项选择题
All of the following will interfere with a 2.4GHz wireless phone EXCEPT:（）
A.Bluetooth.
B.802.11a.
C.802.11b.
D.802.11g.
单项选择题
Which of the following protocols should be used to monitor network performance?（）
A.SNTP
B.SMTP
C.HTTP
D.SNMP
单项选择题
Which of the following networks would MOST likely require EGP routing?（）
A. Networks that use OSPF in addition to static routes
B. Networks with classless Internet domain routing
C. Networks with multiple ISPs
D. Networks that use encryption
单项选择题
Which of the following DNS record types provides the hostname to IP address mapping?（）
A. A record
B. NS record
C. CNAME record
D. MX record
单项选择题
Users are unable to access the Internet but the users are able to send/receive email from theirdesktops. Which of the following ports is MOST likely being blocked?（）
A.25
B.80
C.110
D.143