单项选择题
What is a valid multicast MAC address?（）
A. 00:90:69:9f:ea:46 B. ff:ff:ff:ff:ff:ff C. 01:00:5e:28:12:95 D. 99:99:99:99:99:99
单项选择题 In the MAC address 00: : :9f:eA. , what represents the Organizationally Unique Identifier (OUI)?（）
多项选择题 Which two fields are found in an Ethernet frame header?（）
多项选择题 Which two statements are correct about Layer 2 broadcast frames?（）
