多项选择题
A.The transport layer divides a data stream into segments and may add reliability and flow control information.
B.The data link layer adds physical source and destination addresses and an FCS to the segment.
C.Packets are created when the network layer encapsulates a frame with source and destination host addresses and protocol-related control information.
D.Packets are created when the network layer adds Layer 3 addresses and control information to a segment.
E.The presentation layer translates bits into voltages for transmission across the physical link.
单项选择题 A receiving host computes the checksum on a frame and determines that the frame is damaged.The frame is then discarded.At which OSI layer did this happen?（）
单项选择题 A network administrator is verifying the configuration of a newly installed host by establishing an FTP connection to a remote server. What is the highest layer of the protocol stack that the nework administrator is using for this operation?（）
单项选择题 Refer to the exhibit, Host A pings interface S0/0 on router 3, what is the TTL value for that ping?（）