In order to ping an Ubuntu box using its NetBIOS name, use the following steps:

  1. edit /etc/nsswitch.conf
  2. Replace this line:
    hosts: files dns
    
  3. With this line:
    hosts: files dns wins
    
  4. Next, install winbind:
    sudo apt-get install winbind. 
    
  5. Now the machine should be ready to ping from Windows.