Practical Hacking Techniques and Countermeasures

710  Practical Hacking Techniques and Countermeasures

Chapter Tool Syntax

Chapter 6

(continued)

Packit a ack number The acknowledgment (ACK) number

defines the next sequence number that the sender of

the ACK expects to see. It is typically the sequence

number + 1 during valid TCP communication. It is a 32-

bit unsigned (positive) number.

-W window size The window size provides flow control.

It is a 16-bit number that defines how many bytes the

receiver is willing to accept. The default value is 1500.

-u urgent pointer In valid TCP communication, the urgent

pointer is only useful if the URG flag is set. Used with

the sequence number, it points to the last ...