Windows - Installing a Loopback Adapter

Dynamic Host Configuration Protocol (DHCP) assigns dynamic IP addresses on a network. Dynamic addressing allows a computer to have a different IP address each time it connects to the network. In some cases, the IP address can change while the computer is still connected. You can have a mixture of static and dynamic IP addressing in a DHCP system.

In a DHCP setup, the software tracks IP addresses, which simplifies network administration. This lets you add a new computer to the network without having to manually assign that computer a unique IP address. However, before installing Oracle Database onto a computer that uses the DHCP protocol, you need to install a loopback adapter to assign a local IP address to that computer.

When you install a loopback adapter, the loopback adapter assigns a local IP address for your computer. After you install a loopback adapter on your computer, you have at least two network adapters on your computer: your own network adapter and the loopback adapter.

To check if a loopback adapter is installed on your computer, run the ipconfig /all command:

SYSTEM_DRIVE:\> ipconfig /all

If there is a loopback adapter installed, you would see a section that lists the values for the loopback adapter. For example:

Ethernet adapter Local Area Connection 2:
  Connection-specific DNS Suffix  . :
  Description . . . . . . . . . . . : Microsoft Loopback Adapter
  Physical Address. . . . . . . . . : 02-00-4C-4F-4F-50
  DHCP Enabled. . . . . . . . . . . : Yes
  Autoconfiguration Enabled . . . . : Yes
  Autoconfiguration IP Address. . . : 169.254.25.129
  Subnet Mask . . . . . . . . . . . : 255.255.0.0

Windows 2000 reports on the last network adapter installed. This means that if you install additional network adapters after you install the loopback adapter, you need to remove and reinstall the loopback adapter. The loopback adapter must be the last network adapter installed on the computer.

To install a loopback adapter on Windows 2000:

• From the Start menu, select Settings, then Control Panel.
• Double-click Add/Remove Hardware to start the Add/Remove Hardware wizard.
• In the Welcome window, click Next.
• In the Choose a Hardware Task window, select Add/Troubleshoot a device, and click Next.
• In the Choose a Hardware Device window, select Add a new device, and click Next.
• In the Find New Hardware window, select No, I want to select the hardware from a list, and click Next.
• In the Hardware Type window, select Network adapters, and click Next.
• In the Select Network Adapter window, do the following:
  • Manufacturers: Select Microsoft.
  • Network Adapter: Select Microsoft Loopback Adapter.
  • Click Next.
• In the Start Hardware Installation window, click Next.
• In the Completing the Add/Remove Hardware Wizard window, click Finish.
• Right-click My Network Places on the desktop and select Properties. This displays the Network and Dial-up Connections control panel.
• Right-click the connection that was just created. This is usually “Local Area Connection 2”. Select Properties.
• On the General tab, select Internet Protocol (TCP/IP), and click Properties.
• In the Properties dialog box, click Use the following IP address and do the following:
  • IP Address: Enter a non-routable IP address for the loopback adapter. Oracle recommends the following non-routable addresses:
    • 10.10.10.10
    • 192.168.x.x (x is any value between 0 and 255)
  • Subnet mask: Enter 255.255.255.0.
  • Record the values you entered, which you will need later in this procedure.
  • Leave all other fields empty.
  • Click OK.
• Close the Network Connections window.
• Restart the computer.
• Add a line to the SYSTEM_DRIVE:\WINNT\system32\drivers\etc\hosts

For example:

      10.10.10.10   mycomputer.mydomain.com   mycomputer

• Check the network configuration:
  • Open System in the Control Panel, and select the Network Identification tab.

In Full computer name, make sure you see the host name and the domain name, for example, sales.us.mycompany.com.

• Click Properties.

In Computer name, you should see the host name, and in Full computer name, you should see the host name and domain name. Using the previous example, the host name would be sales and the domain would be us.mycompany.com.

• Click More. In Primary DNS suffix of this computer, the domain name, for example, us.mycompany.com, should appear.
• Exit the System Control Panel.

To install a loopback adapter on Windows 2003 or Windows XP:

• Open the Windows Control Panel.
• Double-click Add Hardware to start the Add Hardware wizard.
• In the Welcome window, click Next.
• In the Is the hardware connected? window, select Yes, I have already connected the hardware, and click Next.
• In the The following hardware is already installed on your computer window, in the list of installed hardware, select Add a new hardware device, and click Next.
• In the The wizard can help you install other hardware window, select Install the hardware that I manually select from a list, and click Next.
• From the list of hardware types, select the type of hardware you are installing window, select Network adapters, and click Next.
• In the Select Network Adapter window, make the following selections:
  • Manufacturer: Select Microsoft.
  • Network Adapter: Select Microsoft Loopback Adapter.
• Click Next.
• In the The wizard is ready to install your hardware window, click Next.
• In the Completing the Add Hardware Wizard window, click Finish.
• If you are using Windows 2003, restart your computer.
• Right-click My Network Places on the desktop and choose Properties. This displays the Network Connections Control Panel.
• Right-click the connection that was just created. This is usually named “Local Area Connection 2”. Choose Properties.
• On the General tab, select Internet Protocol (TCP/IP), and click Properties.
• In the Properties dialog box, click Use the following IP address and do the following:
  • IP Address: Enter a non-routable IP for the loopback adapter. For instance :
    • 10.10.10.10
    • 192.168.x.x (x is any value between 0 and 255)
  • Subnet mask: Enter 255.255.255.0.
  • Leave all other fields empty.
  • Click OK.
• Click OK.
• Close Network Connections.
• Restart the computer.
• Add a line to the SYSTEM_DRIVE:\WINNT\system32\drivers\etc\hosts with the following format, after the localhost line:

For example:

      10.10.10.10   mycomputer.mydomain.com   mycomputer

• Check the network configuration:
  • Open System in the Control Panel, and select the Computer Name tab. In Full computer name, make sure you see the host name and the domain name, for example, sales.us.mycompany.com.
  • Click Change. In Computer name, you should see the hostname, and in Full computer name, you should see the host name and domain name. Using the previous example, the host name would be sales and the domain would be us.mycompany.com.
  • Click More. In Primary DNS suffix of this computer, you should see the domain name, for example, us.mycompany.com.

To install a loopback adapter on Windows Vista:

• Open the Windows Control Panel.
• Double-click Add Hardware to start the Add Hardware wizard.
• In the Welcome window, click Next.
• In the The wizard can help you install other hardware window, select Install the hardware that I manually select from a list, and click Next.
• From the list of hardware types, select the type of hardware you are installing window, select Network adapters, and click Next.
• In the Select Network Adapter window, make the following selections:
  • Manufacturer: Select Microsoft.
  • Network Adapter: Select Microsoft Loopback Adapter.
• Click Next.
• In the The wizard is ready to install your hardware window, click Next.
• In the Completing the Add Hardware Wizard window, click Finish.

The remaining steps are same as given for Windows XP.

To remove a loopback adapter:

• Display System in the Windows Control Panel.
• In the Hardware tab, click Device Manager.
• In the Device Manager window, expand Network adapters. You should see Microsoft Loopback Adapter.
• Right-click Microsoft Loopback Adapter and select Uninstall.
• Click OK.

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