|  |  | Domain Name Service (DNS) is another non-authenticating protocol. For example, whenever you enter www.globalknowledge.com into your Web browser, your system contacts a DNS server to get the IP address to access the Global Knowledge Web site. If the DNS server does not know the IP address, it contacts another DNS to find the answer, which it will then pass on to your system. If hackers are able to respond to your request with an incorrect IP address, the answer will not be authenticated by your system or your DNS server. This attack results in your inability to connect to the desired Web site.