How to change DNS in Ubuntu?

DNS(Domain Name System)

Google public dns

• open NETWORK option in system settings
  
   
•  click options in the window that appears
                          
  • Select the IPv4 Settings or IPv6 Settings  
    
    
  •  select Automatic (DHCP) addresses only and enter DNS server add.
     in DNS server field
                     
    

    • For IPv4: 8.8.8.8 and/or 8.8.4.4.
    • For IPv6: 2001:4860:4860::8888 and/or 2001:4860:4860::8844

       
    
     save your current options and enjoy