In TCP communications there are 8 flags; FIN, SYN, RST, PSH, ACK, URG, ECE, CWR. These
flags have decimal numbers assigned to them:
FIN = 1
SYN = 2
RST = 4
PSH = 8
ACK = 16
URG = 32
ECE = 64
CWR = 128
Jason is the security administrator of ASPEN Communications. He analyzes some traffic using
Wireshark and has enabled the following filters.
What is Jason trying to accomplish here?
A.
SYN,FIN,URG and PSH
B.
SYN,SYN/ACK,ACK
C.
RST,PSH/URG,FIN
D.
ACK,ACK,SYN,URG
A is the Right Ans.
Ans: B
Convert the hex values to decimal.
0x02 = 2 (SYN)
0x12 = 18 –> 0x10 — 16 (ACK) / 0x02 — 2 (SYN)
0x10 = 16 –> ACK
tcp.ack==1 (3 way comm is completed with ACK flag)
tcp.len == 0 (ACK flag confirms connection, no data is needed to acknowledge the connection)