单项选择题
A. Disable TELNET
B. Disable IGMP snooping
C. Enable TELNET but not SSL
D. Disable ICMP/ping on device
单项选择题 Web users are reporting issues downloading various types of media. Which of the following shouldthe administrator do FIRST?（）
单项选择题 When debugging a routing problem, the time-to-live (TTL) value can be used to determine:（）
单项选择题 An administrator has found interference on a network. Which of the following cable types is thenetwork MOST likely composed of?（）