Domain name system (DNS) is used by devices to locate websites by mapping a domain name to a website’s IP address.

A FortiGate can serve different roles based on user requirements:

  • A FortiGate can control what DNS server a network uses.
  • A FortiGate can function as a DNS server.

FortiGuard Dynamic DNS (DDNS) allows a remote administrator to access a FortiGate's Internet-facing interface using a domain name that remains constant even when its IP address changes.

FortiOS supports DNS configuration for both IPv4 and IPv6 addressing. When a user requests a website, the FortiGate looks to the configured DNS servers to provide the IP address of the website in order to know which server to contact to complete the transaction.

The FortiGate queries the DNS servers whenever it needs to resolve a domain name into an IP address, such as for NTP or web servers defined by their domain names.

The following topics provide information about DNS: