Oracle Enterprise Manager Configure Auto Discovery

There are a couple of ways on how to add new hosts to Oracle Enterprise Manager. One of the methods you can use is the auto discovery option. When using this option Oracle Enterprise Manager will start scanning a specific range of IP addresses to identify hosts.  This might in some cases where you have to discover and add a large range of new hosts be the ideal way of doing things. To start a auto discovery porcess within Oracle Enterprise manager you have to start with selecting the menu option "Configure Auto Discovery" which can be found under "Setup" and then "Add Target".

This is the first step in a guided process. The main steps of the Oracle Enterprise Manager auto discovery option are shown here below.

On the setup page select the "Host and Oracle VM Manager Discovery Using IP Scan" option. This is the option that will help you to scan a range of IP address to find hosts that can be added to Oracle Enterprise Manager.

In the below shown "Host Discovery (agentless)" screen select the create option to create a new scan.

This will bring you to the page where you can specify the details of the scan. In the "Host Discovery Specification" screen you will have to enter a name for your scan and an optional description. Next to this you will have top add an agent to the scan. This will be the agent that will be performing the scan. This means that, if you have segregated your network in zones, you might want to give it some extra thought before selecting just a random agent.

After selecting an agent you will have to state the IP range you want to scan. In the example below I will be scanning the IP addresses 192.168.1.135 up until 192.168.1.145. You can use a number of options to specify IP ranges or hostnames. From the Oracle Enterprise Manager manual you can read the following options:

Select the agent in the IP Ranges for scan table, and enter the IP ranges to scan. You can specify any or even all of the following:

• One or more absolute hostnames, each separated by a space; for example: host1.example.com host3.example.com
  
• One or more IP addresses, each separated by a space
  
• A range of addresses; for example: 10.0.0-255.1-250. Note that IP addresses and IP ranges must be separated by a comma; for example: 10.0.0-255.1-250
  
• Classless Inter-Domain Routing (CIDR) notations; for example: 128.16.10.0/24
  

Separate each value with a space; for example:
host1.example.com 192.168.0.1 128.16.10.0/24 10.0.0-255.1-250,254

Next to adding the information on the "Scan Details" tab you will have to specify some details under the "Job Details" tab. On this tab, as shown below you will have to enter the credentials used to perform the scan from the host where the agent is used. You will have to have configured the sudo privileges to enable the host to perform the scan.

After setting the correct credentials you can click the "Save and Submit IP Scan" button to start the scan. This will schedule the scan. The scheduled scan and the final results will be shown in the overview screen as shown above where you will be able to zoom to the details of the discovered hosts. 

As you can see in the above screenshot the discovery job has completed with success. By using the results of this scan you can take next steps to add the discovered hosts to Oracle Enterprise Manager.