DNS

If you are using fully qualified domain names (FQDN) instead of IP addresses for some of your device configuration, the domain names need to be resolved into IP addresses by Domain Name System servers. The device provides various ways to do this:

External, third-party DNS servers:
DNS servers configured in the IP Interfaces table for the associated IP network interface (see Configuring IP Network Interfaces)
Default DNS servers (see Configuring Default DNS Servers)
Device's embedded DNS (and SRV) server:
Internal DNS table (see Configuring the Internal DNS Table)
Internal SRV table (Configuring the Internal SRV Table)