多项选择题 Which two are valid fields in an IPv6 header?（）

单项选择题 You have a firewall filter applied in an inbound direction on a customer interface. You would like this filter to protect your network from a spoofed denial of service attack. Which action should be configured to accomplish your goal?（）

单项选择题 Which code causes only a Level 2 adjacency to be formed under the SONET interface so-2/2/2 withFrame Relay encapsulation?Which code causes only a Level 2 adjacency to be formed under the SONET interface so-2/2/2 with Frame Relay encapsulation?（）