title: internet is not working in virtualbox linux(CentOS 7)
body: <p>Internet is not working in my virtual machine (CentOS 7)</p>
  
  <p>I don't know where to start...
  machine has two network adapter, NAT and Host 
  I can ping among virtual machines such as "ping slave1" "ping slave2" .... it works just fine</p>
  
  <ol>
  <li><p>ping 8.8.8.8 </p>
  
  <p>-> PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data. </p></li>
  </ol>
  
  <p>after this message, nothing comes out..</p>
  
  <ol start="2">
  <li><p>ping google.com</p>
  
  <p>-> no any message comes out for a while and it says "ping: unkown host google.com"</p></li>
  <li><p>enp0s3 -> NAT(on)</p>
  
  <p>-> inet 10.0.2.15
  -> netmask 255.255.255.0</p></li>
  <li><p>enp0s8 -> host(on)</p>
  
  <p>-> 192.168.56.101</p></li>
  </ol>
  
  <p>Where should I start to figure it out?</p>
  
  <p>Please I am spending more than 17 hours for this...</p>