单项选择题
Which command enables RSTP on a switch?（）
A. spanning-tree mode rapid-pvst B. spanning-tree uplinkfast C. spanning-tree backbonefast D. spanning-tree mode mst
单项选择题 DNS servers provide what service?（）
单项选择题 There are no boot system commands in a router configuration in NVRAM.What is the fallback sequence that router will use to find an ios during reload?（）
单项选择题 Which command shows your active Telnet connections?（）
