NETWORK SECURITY
INTRODUCTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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PSH
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FIN
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SYN
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URG
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Detailed explanation-1: -TCP uses a three-way handshake to establish a reliable connection. The connection is full duplex, and both sides synchronize (SYN) and acknowledge (ACK) each other. The exchange of these four flags is performed in three steps: SYN, SYN-ACK, ACK, as shown in Figure 5.8.
Detailed explanation-2: -The SYN flag synchronizes sequence numbers to initiate a TCP connection. The FIN flag indicates the end of data transmission to finish a TCP connection. Their purposes are mutually exclusive.
Detailed explanation-3: -As with all flags, a value of ‘1’ means that a particular flag is ‘set’ or, if you like, is ‘on’. In this example, only the “SYN” flag is set, indicating that this is the first segment of a new TCP connection.