The following is a dump of a TCP header in hexadecimal format:

00CD0018 00000EF1 00000D5D 502200D1 01BF0010

We need to first split the above hex as such

00 CD 00 18 00 00 0E F1 00 00 0D 5D 50 22 00 D1 01 BF 00 10

1.1  What is the source port number?

Source port is 2 bytes take 00 CD   = 205

           (00 CD 00 18 00 00 0E F1 00 00 0D 5D 50 22 00 D1 01 BF 00 10)

1.2  What is the destination port number?

Next 2 bytes as destination address 00 18 = 24

1.3  What is the sequence number?

Next 4 bytes as sequence number 00 00 0E F1 = 3825

1.4  What is the acknowledgment number?

Next 4 bytes as acknowledgment number 00 00 0D 5D = 3421

1.5  What is the length of the header?

Next 4 bits as HLEN 5 (this indicates number of sets of 4 bytes which makes the header lenght = 20bytes)

1.6  Which control bits are set and what do they represent?

Next 6 bits are reserved 02 = 02 (10 - remaining (binary))

Next 6 bits are control bits 22= 34 (100010)

1.7  What is the window size?

Next 2 bytes indicate the window length 00 D1 =209