?
Solved

what are listeners?

Posted on 2004-05-01
6
Medium Priority
?
242 Views
Last Modified: 2010-04-11
Hi there,

I hope if anyone help me on giving me a brief description about listeners in general..

or some webpages that will explain them for me,

thanks in advance,
waiting for ur answers :)
0
Comment
Question by:SEstudent
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
6 Comments
 

Author Comment

by:SEstudent
ID: 10966359
I must say that my question is about (port listeners)..
0
 
LVL 37

Accepted Solution

by:
bbao earned 172 total points
ID: 10966672
commonly, a listener is a program that is used to accept incoming connections, in order to provide specific services. it opens one or several listener sockets, each accepting TCP/IP connections on a specified port number, and, optionally on a specified local IP address.

hope it helps,
bbao
0
 
LVL 11

Assisted Solution

by:rafael_acc
rafael_acc earned 164 total points
ID: 10967811
A listener is an Operating System Service wich waits for a connection on a predefined port, using a predefined protocol. Note that when using tcp/ip, different protocols may be used (because TCP/IP its a protocols stack) for example: ftp, smpt, http, ... etc. Each of these protocols use already defined fixed ports (known as well known ports). However there are services wich open ports in a dinamic fashion, only when needed.

If you type at your command prompt, "netstat -na <enter>" then you will better understant that. Trust me !

Cheers.
0
 
LVL 7

Assisted Solution

by:fifthelement80
fifthelement80 earned 164 total points
ID: 10970269
u should know some basic knowledge of networking first let me explain u some basics :
1.in IP protocol every pc connected to network has an unique IP address and 65535 ports available to use.
2.every application uses some specific port number (it is software based not hardware) to let other clients or applications to communicate with it.
3.if an application listen on some port then that port is assumed as open.
4.1024 ports have common specific use like : 80 for WWW 21 for ftp 23 for telnet and ...
An Example :
your IP address is : 192.168.10.1
u have an webserver on your computer running then your webserver listens on port 80 and port 80 is open.
other computers connect through your computer through this address : http://192.168.10.1:80 (because of http 80 is not required)
and so they will be able to communicate to your application
Hope it helps

0

Featured Post

Get your Conversational Ransomware Defense e‑book

This e-book gives you an insight into the ransomware threat and reviews the fundamentals of top-notch ransomware preparedness and recovery. To help you protect yourself and your organization. The initial infection may be inevitable, so the best protection is to be fully prepared.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Sometimes clients can lose connectivity with the Lotus Notes Domino Server, but there's not always an obvious answer as to why it happens.   Read this article to follow one of the first experiences I had with Lotus Notes on a client's machine, my…
Make the most of your online learning experience.
Get a first impression of how PRTG looks and learn how it works.   This video is a short introduction to PRTG, as an initial overview or as a quick start for new PRTG users.
In this video we outline the Physical Segments view of NetCrunch network monitor. By following this brief how-to video, you will be able to learn how NetCrunch visualizes your network, how granular is the information collected, as well as where to f…

719 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question