Loopback adapter, what was that? another tutorial in dynamips tell about loopback adapter.
After googling for a while I found some interesting link to help me to answer my question.

Loopback adapter, this adapter suitable for computer who don’t have network adapter installed.

I see, I already use vmware where I can add new adapter as much as I can
I like graphic visualization , here’s the steps :

1.  The network before add loopback adapter

2. Open Control Panel

3. Double click on Add Hardware

4. Click Next

5. Wizard will search

6. Choose, ‘Yes, I have already connected the hardware’

7. Choose ‘Network adapters’

7. Choose ‘Microsoft Loopback Adapter’

8. Click Next

9. Click Finish

10. Network connection after loopback adapter added.

By default ‘Local Area Connection 2′ use DHCP

Great, I learn howto add loopback adapter, will try in my old computer at home