13

A bit of trivia... the Domain Name System (DNS) is an established infrastructure that permits surfers to access sites without the need to memorise IP addresses but instead type in domain names that are then translated. It is the foundation of what we know as the World Wide Web (WWW) and will affect the global community if they are not available. The DNS root servers are often targeted by hackers to cause disruption.

There are 13 root servers that support the Internet. The reason for this significant number is the use of UDP packets for DNS queries. UDP packets are 512 bytes in size and can only store a maximum of 13 DNS root server details.