Monthly Archives: August 2011

Graph your network environment with Cacti

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There are many commercial and open source solution out there to graph your network utilization and in this article I am going to show you how to use Cacti the open source RRDTool-based graphing solution. Cacti is freely available at http://www.cacti.net and comes preloaded with a few Host and Graph Templates. If a template for the device you are trying to set up is not available by default you can download contributed cacti host and graph templates at http://docs.cacti.net/templates and import those to your cacti installation.

The installation and configuration for Cacti is on Ubuntu very simple. Let’s go over the installation procedure. First I recommend that you always update your apt-get repository with

sudo apt-get update

and then you can go ahead and install the latest version available from the repository with

sudo apt-get install cacti cacti-spine

accept all dependencies and the installation will start. During the installation the installer probably ask you a few questions depending on your current system setup but on a fresh install it most likely will ask your if you like to install MySQL and for a SQL Root user password. Further more it will also ask you if you like to use db-config to setup the cacti SQL Database and it will also ask for a password again. The next step it will ask you if you like to configure the installation for a version of apache web server. I recommend to use Apache2 unless you know what you are doing.

Now the installation should be done and the next step of the configuration is web based. Start you preferred web browser and browse to http://yourserver/cacti and you will see a disclaimer if your installation worked as planned, click next to start the web based configuration. Read the information displayed on those pages and make sure that there are now errors and click on finish at the end. If you run into errors try to solve those and re-run the steps until everything is the way it suppose to be.

Now you are done and you can browse to your Cacti website again and this time it should ask to to login. Use admin for the user name and password. The Cacti website now forces you to change your admin password for the website. Enter a desired password. Now there are two things that needs to be checked that they are correct. On the left pane click on settings and in the right pane click on the tab Paths. Make sure that all paths are green and it states that the file is found. Click on the Poller tab and change the poller from cmd.php to spine and scroll all the way to the bottom and click on save. Now you are done and can start adding devices and graphs.

Watch the video below to see the entire installation, configuration and adding devices and graphs. If you like the video don’t forget to rate it and leave a comment if you like.

Thanks for reading and enjoy the video.

Test Post

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simple send only mail daemon with sSMTP

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Are you in the situation of managing a network without your own in-house mail server but still to receive messages from your servers like: warning, logs, error or any kind of notification? Than this article might be the one you are looking all along. In this article I will introduce you to sSMTP which is short for Simple SMTP. sSMTP is a sendmail emulator and not a full fletched smtp mail daemon.

In order to install it open up a terminal and type the following line:

sudo apt-get install ssmtp

accept the dependencies. After the installation is done we have to go and touch the two configuration files located in the /etc/ssmtp/ directory. The is a ssmtp.conf and a revaliases file. Lets start with ssmtp.conf. type the following line:

sudo nano /etc/ssmtp/ssmtp.conf

and make it look like this:

root=youremail@domain.com
mailhub=smtp.mailserver.com:25
hostname=yourhostname.domain.com
AuthUser=loginusername
AuthPass=loginpassword
UseSTARTTLS=yes
UseTLS=yes
FromLineOverride=yes

when done save the file. Let’s go over the configuration directives.

root=youremail@domain.com          : You specify the user who is getting all mail for userids less than 1000

mailhub=smtp.mailserver.com:25   : You specify the host to send mail to

AuthUser=loginusername                 : You specify the login username to login to the host

AuthPass=loginpassword                  : You specify the login password to login to the host

UseSTARTTLS=yes                            : You specify whether or not to use STARTTLS yes/no

UseTLS=yes                                         : You specify whether or not to use TLS yes/no

FromLineOverride=yes                     : You specify whether the from header of an mail may override the default domain

Next is to edit the revaliases file. Type sudo nano /etc/ssmtp/revaliases and add the following line:

root:youremail@domain.com:smtp.domain.com:25

A reverse alias gives the From: address placed on a user’s outgoing messages and (optionally) the mailhub these messages will be sent through.

Save the file and let’s get it tested. Type in the following line and hit enter.

echo “This is a test message” | mailx -s ‘Test Message’ yourmail@domain.com

Now start your mail client and you should receive this test message if everything is configured correctly.

You can also watch the following Video clip that demonstrated exactly what I just have written up for you.

Enjoy!