The last post of our serie ‘Install Sonar’ described the installation and configuration of Oracle.

As it was already long enough, we could not see some tips and tricks that can be useful to verify that Oracle is installed and usable.

If your installation was a on a computer of you company, with a network connection, then your Oracle should already be working correctly.

In fact, Oracle requires an IP address in order to work. And without going into details, if your PC is running on a network, you already have an IP address. If you’re not always – if ever – connected to a corporate network, you will need a local IP address. It is the role of the Loopback Adapter, which simulates a network loop on your computer.

We will discuss in this post how to install a Loopback Adapter needed to use Oracle on a standalone station, such as a laptop for example.

The first thing to do is to check if you already have one on your machine.

Check if a Loopback Adapter is installed

To do this, open a DOS window (cmd.exe), and type the command ipconfig /all.
Here is the result on my PC:

• First, the name of my computer: JPFPC.
• Then a Network Adapter named ‘Microsoft Loopback Adapter’, with its configuration.

How has been created this Loopback Adapter? This is what we will see now.

Installing a Loopback Adapter

During this installation, the Loopback Adapter will assign an IP address to your local machine.

You most likely already have a network, either in your company, or just a wifi connection at home. Some recommend setting the Loopback Adapter as a primary connection, but this is not essential. All applications will be routed to the Internet or your local network (Ethernet card), but tools such as Oracle Enterprise Manager will use your local IP address.

To proceed with the installation, select the Windows menu ‘Start’ (or hit the ‘Windows’ key) and enter ‘hdwwiz’ in the search field (search box). The search result should return a menu of the same name, that you can click to get this window:

In this Welcome window, click ‘Next’. In the following window:

Select the option ‘Install the hardware that I manually select from a list’. Then ‘Next’ to continue.

From the list of hardware types, select ‘Network adapters’ and again click ‘Next’. Windows takes a little time to populate the list of different network adapters available, then displays the following window:

In this window, select:

• Manufacturer : ‘Microsoft’.
• Network Adapter : ‘Microsoft Loopback Adapter’.

‘Next’ to continue and again ‘Next’ when Windows tells us that it is ready to install:

In the window ‘Completing the Add Hardware Wizard’, click the button ‘Finish’.

Once the installation is complete, click the button ‘Finish’ to exit this installation Wizard.

Configuring le Loopback Adapter

We will now configure the Loopback Adapter. Open the Control Panel, select ‘Network and Internet’, then ‘Network and Sharing Center’.

I already have a WiFi connection, and I can see a local connection which corresponds to the LoopBack Adapter I just installed. It can also be displayed with the name ‘Local Area Connection 2’ if you already have a network connection.

Click on this connection to display its status in the following window:

Click the ‘Properties’ button and in the next window:

… select ‘Internet Protocol Version 4 (TCP/IPv4)’.

Again, click ‘Properties’:

We will be able to configure our Loopback Adapter in this new window:

• Select the radio-button ‘Use the following IP address’.
• In the field ‘IP adress :’, enter an IP address for your Loopback Adapter.

Oracle recommends to use a non-routable address, inside a private address range that allows to avoid conflict with a public IP address. These addresses are called non-routable and their ranges are as follows:

• From 10.0.0.0 to 10.255.255.255.
• From 172.16.0.0 to 172.31.255.255.
• From 192.168.0.0 to 192.168.255.55.

For small home networks, we generally use the address range 192.168.0.1 to 192.168.0.255.

• In the ‘Subnet mask’ field, enter 255.255.255.0.

Note the value that you selected for your IP address: 192.168.254.254 in my example.

Select ‘OK’ to close this window, then ‘Close’ in the two other windows.

The ‘hosts’ file

The last thing we need to do to complete the configuration of our Loopback Adapter is to add the corresponding IP address intho the ‘hosts’ file. You will find this file into the directory ‘C:\Windows\System32\drivers\etc\’.

Here is how looks mine:

Add a new line at the end of this file with the IP address you have chosen for your Loopback Adapter and a host name that you want to assign to this address (JPFPC in my example). Depending on your operating system, you may need to restart your computer.

To verify that everything works well, we will ‘ping’ this address to see if it responds correctly: use the ‘Ping’ command into a DOS windows, followed by the address (host name or IP address itself directly).

In this example, the command ‘Ping JPFPC’ shows the IP address defined for our Loopback Adapter.

We have finished with our configuration. Oracle can now run on our standalone workstation, when it is not connected to a network.

The next post will focus again on other tips and tricks about Oracle, useful to know before installing Sonar.

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