I wonder why HPING3 has two different flags for setting TCP ACK...

-A --ack: Set ACK tcp flag.

-L --tcpack: Set the TCP ack.


There has to be a difference, but I don't know.....

Can someone through some light on that ?

thanks

Soapp

On 30 Mar 2007, in the Usenet newsgroup comp.security.firewalls, in article
<1175259164.504210.159720 [at] l77g2000hsb.googlegroups.com>, Soapp wrote:

>I wonder why HPING3 has two different flags for setting TCP ACK...

[compton ~]$ whatis hping3
hping3 (8) - send (almost) arbitrary TCP/IP packets to network hosts
[compton ~]$

Versatility.

>-A --ack: Set ACK tcp flag.
>
>-L --tcpack: Set the TCP ack.
>
>There has to be a difference, but I don't know.....

0793 Transmission Control Protocol. J. Postel. September 1981.
(Format: TXT=172710 bytes) (Updated by RFC3168) (Also STD0007)
(Status: STANDARD)

Section 3.1 - you can find the RFC using the same search engine you are
posting from.

>Can someone through some light on that ?

What is the difference between 12th bit in the fourth 32 bit word (ACK) of
a TCP header and the entire third 32 bit word of the header?

Old guy

> What is the difference between 12th bit in the fourth 32 bit word (ACK) of
> a TCP header and the entire third 32 bit word of the header?
>
> Old guy


Oh, I see,

-L --tcpack, sets the 32 Bit TCP ackknowledge Number :)

Thank you