How to build your own Network Mgmt System?

Anindya Roy

Let's start this article with a few questions. How fast can you rollout an NMS (Network Monitoring System)? 2 Months? 2 weeks? 2 days? 2hours? No, its two minutes! Can't believe me? Ok, then take out your stop watch and start counting, while we start the process of rolling out an NMS system.

Backgrounder

If you remember, we had an article about how to configure an NMS system with alerts and using OpenNMS, around a couple of years back. It was a two page story, with lots of configurations, dependency hazards, and CLI. But, today we will be configuring the same OpenNMS (well, not exactly the same. It's an updated version) in just a couple of minutes.

Let us briefly talk about what OpenNMS is, just for recap. OpenNMS is an Open Source Network Management System, which runs on any OS that supports Java and Tomcat. This software is capable of SNMP service polling, data collection, notification and event management. Using this software you can monitor your crucial servers and individual services running on them such as HTTP, FTP, MySQL; that too in an agent less environment.

The installation of OpenNMS is pretty tedious, and you need to configure quite a few components such as Tomcat, Java to make it work. So, to minimize the time consumed when deploying OpenNMS, we will go the Virtualization way. This time we are also carrying VMware appliance of OpenNMS in our DVD, which is pre-installed and pre-configured with everything. So, let us start the roll out the process.

Getting the NMS Ready

To deploy this NMS all you're required to do is to copy and unpack the zipped files named OpenNMS-VM, and load it using any VMware client such as VMware player or VMware Workstation.

We loaded it on top of the VMware Player. Here, we have a word of caution for you. This 600 MB file when inflated yields a huge 12 GB VMD file, so make sure you have that much of free disk space. Once booted into the appliance, login using 'root' as username and 'pppppp' as password.

Now, to make sure that you have got an IP, run the 'ifconfig' command. Now, you have to run some commands and do some configurations. Change directory to “/opt/opennms/etc” by running the following command and open the file called 'discovery-configuration.xml.'

#cd /opt/opennms/etc

#vi discovery-configuration.xml

Now, you will see a section like this in the file:

192.168.0.1

192.168.0.254

Here, change the IP addresses in starting and ending tags, with the IP addresses which make your range. For instance, on have a 192.168.3.x network, we will put 192.168.3.1 in the starting tag and 192.168.3.254 in the ending tag. Once this is done, save your settings and then close the editor. Now, run the following commands in the given sequence to start Tomcat and OpenNMS server:

#/etc/init.d/tomcat5 start

#/opt/opennms/bin/opennms strat

So, now your NMS is up and running.

Using the system

Once you get the IPs, go to any machine on the same network and open up your favorite browser. Now type in the address “http ://: 8080/opennms,” and you will be prompted with the login screen of OpenNMS.

Log in to this screen as admin with the password 'admin'. This is the default username of OpenNMS interface. Once you login, the OpenNMS dashboard pops up. As you have defined the default range of your network, OpenNMS will automatically discover all nodes on the network and will also check for the services available on those nodes. Now, see how much time it took you to build the system?

Configuring Notification

The final thing, which youcan do, is to configure notifications in case of failure of any node or any service specific to any node. OpenNMS is capable of configuring alerts in an escalated fashion. For instance if there is an error in any of the crucial system. So, an alert will be immediately sent to the concerned person and if because of any reason he cannot resolve the problem in a given amount of time, then the system will automatically escalate the matter and send an alert to the next level of support.

To configure this, go to the “Admin” menu at the top of the window. Select the “Configure Notification Path” option and click on the “New Path” button. Now, a new window will open up. Give a name for the notification path.

Now, click on the “Edit” button at the right of the window. In the next window which comes up click on the “add address” button. Now, a dialogue box will open up. Enter in your mail address where you want to receive the notifications, click on “Next” button twice, then click on the “Finish” button and you are all done.