FreeBSD - Tutorials, Security
Home   Archives   Sitemap   About   Contact

List established connections on Unix servers

Home NEW! Unix Forum News 100 Tips and Tricks Website Development Server Operating Systems Databases
 Ivorde.ROarrow Server Operating Systems arrowAdministration GuidesarrowList established connections on Unix servers 

Article Sections

    Hello, Guest !
User name:
Password:
 
Google

 SSD VPS Hosting - Vpsie.com
 Mo.nitor.me
 Ivorde forum
 FreeBSD Tutorials
 Linux LVM Commands
 Free Shell Accounts
 FreeBSD Project
 FreeBSD Handbook
 Advanced Bash-Scripting Guide
 The OpenBSD Project
 Distrowatch
 FreeBSD Handbook


Apache Webserver Home Page

Posted on: 19 Oct 2007
Author: real_mc
Section: Server Operating Systems | Administration Guides
Views: 1755
Comments: 1 (Add)

List established connections on Unix servers
Using netstat to list established connections on UNIX (BSD, Linux) boxes

 



Netstat is a very useful tool for showing network status. It displays the contents of various net-work-related data structures. There are a number of output formats, depending on the options for the information presented.

Netstat:

-a Show the state of all sockets and all routing table entries; normally, sockets used by server processes are not shown and only interface, host, network, and default routes are shown.
-n Show network addresses and ports as numbers. Normally netstat attempts to resolve addresses and ports, and display them symbolically.

For Unix use: netstat -an | grep "ESTABLISHED". This will show established connections on port 80 (http) in this form:

$ netstat -an | grep "ESTABLISHED" | grep ".80 "
tcp4 0 0 192.168.1.10.80 194.212.29.163.63154 ESTABLISHED
tcp4 0 0 192.168.1.10.80 194.212.29.163.63154 ESTABLISHED
tcp4 0 0 192.168.1.10.80 194.212.29.163.63154 ESTABLISHED
tcp4 0 0 192.168.1.10.80 195.45.29.63.63154 ESTABLISHED
tcp4 0 0 192.168.1.10.80 15.212.31.56.63154 ESTABLISHED

On FreeBSD you can also use sockstat -4c command, which is also very usefull to list connected sockets (established connections) on the server. It combines netstat with lsof.

$ man sockstat
NAME
sockstat -- list open sockets

SYNOPSIS
sockstat [-46clu] [-p ports]

DESCRIPTION
The sockstat command lists open Internet or UNIX domain sockets.

The following options are available:

-4 Show AF_INET (IPv4) sockets.

-6 Show AF_INET6 (IPv6) sockets.

-c Show connected sockets.

-l Show listening sockets.

-p ports Only show Internet sockets if either the local or foreign
port number is on the specified list. The ports argument is
a comma-separated list of port numbers and ranges specified
as first and last port separated by a dash.

-u Show AF_LOCAL (UNIX) sockets.

$ sockstat -4c | grep -E "COMMAND|:80"
www httpd 28949 21 tcp4 192.168.1.10:80 193.35.20.13:56011

Of course, output from both commands sockstat -4c and netstat -an | grep "ESTABLISHED" can be redirected to grep or/and wc -l in order to count and/or filter established connections you are interested in.

Bookmarks: Echo "List established connections on Unix servers" around:
del.icio.usdiggFurlYahooMyWebGoogleBookmarksFaceBookTechnocratti
-------------------advertising-----------------

Other articles in Server Operating Systems / Administration Guides
» Windows XP: print LISTEN ports and network connections using netstat
» Unix/Linux/BSD - Show / View sendmail version and upgrade sendmail
» Unix,Linux,FreeBSD - How to rename a list of files, replacing spaces inside their names
» How to check if an rpm package is installed on a Red Hat Linux server
» Calculating the sum and average for a list of values




Contact webmaster regarding this article
Register or Login to post your article
Hello, Guest ! You can Login or Register to www.ivorde.ro!

 Post comment:

Name:
Title:
Comment:
Please type the word you see in the image (anti-spam verification). Refresh the page if you don't understand the word.
Allowed HTML Tags for comments:<p><strong><em><u><h1><h2><h3><h4><h5><h6><img><li>
<ol><ul><span><div><br><ins><del>

1 comment(s) to List established connections on Unix servers:

1. Re: List established connections on Unix servers
sockstat can select port by itself by Dan Farrell at September 07th, 2009 - 11:06
Rather than using grep, it makes a lot of sense to select interesting ports in sockstat directly. `sockstat -4cp 80` is equivilent to `sockstat -4c|grep 80`.

   Latest topics on the forum:
 
   Most viewed articles:
How to copy a mysql database using mysqldump - 9376 views
How to change a user's password in AIX with the output from ECHO command - 8635 views
FreeBSD: Add/remove an additional IP alias - 5609 views
Qmail relay to smarthost: How to route all mail to a smarthost - 3929 views
Print queues in AIX 5L - How to list print queues in AIX - 2884 views

   Latest 10 articles:
Qmail relay to smarthost: How to route all mail to a smarthost - 03 Feb 2009
EXIM 4 relay to smarthost: How to route all mail except local domain - 03 Feb 2009
Windows XP: print LISTEN ports and network connections using netstat - 30 Jan 2009
How to cut out first last n characters from each file name, from a filelist - 04 Nov 2008
Mozilla Firefox3 is now released - 18 Jun 2008
How to switch lower case to upper case and upper case to lower case in a string - 17 Jun 2008
How to rename files/directories to uppercase/lowercase character names - 17 Jun 2008
How to convert lower case to upper case letters in a shell script/command - 17 Jun 2008
Unix,Linux,FreeBSD - How to rename a list of files, replacing spaces inside their names - 12 Jun 2008
How to change a user's password in AIX with the output from ECHO command - 21 May 2008


Archives
» 2007  |  June  |  October  |  November  |  December
» 2008  |  January  |  February  |  March  |  April  |  May  |  June  |  November
» 2009  |  January  |  February



Home | Archives | Sitemap | About | Contact

Designed and developed by Andrei Manescu. Optimized for Mozilla Firefox.  
Copyright 2007 Andrei Manescu
All trademarks and copyrights on this page are owned by their respective owners. Comments are owned by those who posted them.
Valid W3 Document Valid XHTML 1.0 Transitional Valid CSS! The FreeBSD Project Viewable With Any Browser