Re: Port Zero

["STRAMBO" <Strambo () t-online de>]

Hi,

Port 0 is officially a reserved port in TCP/IP networking, meaning that it
should not be used for any TCP or UDP network communications.

However, port 0 sometimes takes on a special meaning in network programming,
particularly Unix socket programming. In this environment, port 0 is a
programming technique for specifying system-allocated (dynamic) ports.

Instead of "hard-coding" a particular port number, or writing code that
searches for an open port, Unix programmers simply specify port 0 as a
connection parameter. That triggers the operating system to automatically
search for and return the next available port in the dynamic port number
range.

This programming technique does not work the same way in Microsoft Windows
as it does in Unix.

Best regards
Strambo

----- Original Message ----- 
From: <omibaba () gmail com>
To: <incidents () securityfocus com>
Sent: Saturday, July 16, 2005 6:14 AM
Subject: Port Zero


> Active Connections
>
>   Proto  Local Address          Foreign Address        State
>   TCP    0.0.0.0:135            0.0.0.0:0              LISTENING
>   TCP    0.0.0.0:445            0.0.0.0:0              LISTENING
>   TCP    0.0.0.0:1025           0.0.0.0:0              LISTENING
>   TCP    0.0.0.0:1028           0.0.0.0:0              LISTENING
>   TCP    0.0.0.0:1054           0.0.0.0:0              LISTENING
>   TCP    0.0.0.0:1307           0.0.0.0:0              LISTENING
>   TCP    0.0.0.0:1344           0.0.0.0:0              LISTENING
>   TCP    0.0.0.0:1445           0.0.0.0:0              LISTENING
>   TCP    0.0.0.0:1447           0.0.0.0:0              LISTENING
>   TCP    0.0.0.0:1452           0.0.0.0:0              LISTENING
>   TCP    0.0.0.0:1453           0.0.0.0:0              LISTENING
>   TCP    0.0.0.0:1455           0.0.0.0:0              LISTENING
>   TCP    0.0.0.0:1460           0.0.0.0:0              LISTENING
>   TCP    0.0.0.0:1465           0.0.0.0:0              LISTENING
>   TCP    0.0.0.0:1466           0.0.0.0:0              LISTENING
>   TCP    0.0.0.0:1469           0.0.0.0:0              LISTENING
>   TCP    0.0.0.0:1491           0.0.0.0:0              LISTENING
>   TCP    0.0.0.0:1496           0.0.0.0:0              LISTENING
>   TCP    0.0.0.0:1498           0.0.0.0:0              LISTENING
>   TCP    0.0.0.0:1507           0.0.0.0:0              LISTENING
>
> Above is the output of netstat -an |more
>
> Guys / Gals Do you know what means port zero in Windoze Platform ? I know
the answer but jst wanted to know anyone has a better explaination.
> In Unix Family port zero is used for socket programming but not the same
in Windoze family.
> I have asked this question in many programs of mine in CEH - Certfied
Ethical Hacking but still awaiting for answers. Lemme see if can get some
answers for this post!!!!
> Ciao
>
> Baba
> CEO
> Appsec