LinuxQuestions.org
Help answer threads with 0 replies.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Newbie
User Name
Password
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!

Notices


Reply
  Search this Thread
Old 08-02-2012, 10:29 AM   #1
godegisel
LQ Newbie
 
Registered: Nov 2010
Posts: 5

Rep: Reputation: 0
Unhappy what the port 0 is used for?


recently I used a port-scan tool,and I found that the port 0 in my machine is openned for all,does it have any bad effect on the security of my system?and what is port 0 userd for?
Thanks for all in advance.

Kind Regards,
G.g
 
Old 08-02-2012, 01:42 PM   #2
camorri
LQ Guru
 
Registered: Nov 2002
Location: Somewhere inside 9.9 million sq. km. Canada
Distribution: Slackware 14.1, 14.2
Posts: 5,189

Rep: Reputation: 526Reputation: 526Reputation: 526Reputation: 526Reputation: 526Reputation: 526
This link explains it. -->http://compnetworking.about.com/od/t...-numbers-0.htm
 
1 members found this post helpful.
Old 08-02-2012, 06:22 PM   #3
jefro
Moderator
 
Registered: Mar 2008
Posts: 17,195

Rep: Reputation: 2562Reputation: 2562Reputation: 2562Reputation: 2562Reputation: 2562Reputation: 2562Reputation: 2562Reputation: 2562Reputation: 2562Reputation: 2562Reputation: 2562
http://www.networksorcery.com/enp/pr...ports00000.htm
 
Old 08-03-2012, 11:11 AM   #4
godegisel
LQ Newbie
 
Registered: Nov 2010
Posts: 5

Original Poster
Rep: Reputation: 0
Thanks for all. the link is useful,content as below.
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 that environment, port 0 is a programming technique for specifying system-allocated (dynamic) ports.
Configuring a new socket connection requires assigning a TCP or UDP port number. Instead of hard-coding a particular port number, or writing code that searches for an available port on the local system, network programmers can instead 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.
Unix, Windows and other operating systems vary slightly in their handling of port 0.
 
Old 08-03-2012, 04:49 PM   #5
jefro
Moderator
 
Registered: Mar 2008
Posts: 17,195

Rep: Reputation: 2562Reputation: 2562Reputation: 2562Reputation: 2562Reputation: 2562Reputation: 2562Reputation: 2562Reputation: 2562Reputation: 2562Reputation: 2562Reputation: 2562
Well, not sure I agree with that. Ports have been listed as common but there is no law that they must be on those ports. You don't need to register any port. You simply use a port as you wish. If it interferes then you would have to fix one or the other. I have used stuff over port 80 to get past firewalls for example. I know people who's ISP blocks port 80 at their home so they run http server on some other port that is open. Many people move remote desktop ports to help secure the connection.

Last edited by jefro; 08-03-2012 at 04:50 PM.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
Tomcat6 stops listening on port 80 when i change from port 8080 to port 80 trongthect Linux - Server 1 07-27-2012 06:41 PM
SFTP server port blocked on Uni network, need to change the listening port. sammyboy161 Linux - Newbie 2 10-21-2010 01:03 PM
LXer: LD Port Report Project aka Switch Port Mapper Tool LXer Syndicated Linux News 0 05-10-2009 08:11 PM
Configuring Automatic Redirects from port 80 to port 443 with bundled Apache server kaplan71 Fedora 1 12-28-2007 09:30 AM
--destination-ports port[,port[,port...]] KevinGuy Linux - Networking 1 03-16-2004 07:06 PM

LinuxQuestions.org > Forums > Linux Forums > Linux - Newbie

All times are GMT -5. The time now is 07:39 AM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration