DNS Server

DSM Version

DNS Server


  • Resolution from domain names to IP addresses for devices or resources connected to the Internet or local area networks (LAN)
  • Master, slave, and forwarding zones that ensure high availability of DNS service
  • Flexible migration of DNS service through robust backup and restoring


  • Supported resource records: A, AAAA, CAA, CNAME, MX, NS, PTR, SPF, SRV, and TXT
  • Manages DNS zones of the domain created by Synology Directory Server
  • Listens on IP address changes of network interfaces to update DNS host records automatically (for AD zones only)
  • Provides access control for zone transferring, DNS queries, and dynamic zone updates
  • Safeguards the following mechanisms via TSIG (Transfer Signature) keys:
    • Synchronization of DNS files
    • Dynamic updates from master zones
  • Sends recursive queries to resolve external DNS records
  • Supports forwarders for resolving external DNS records
  • Supports slave zone notifications
  • Supports importing and exporting zone settings and resource records
  • Supports split-horizon DNS, providing each client with customized DNS information
  • Supports forward and reverse DNS lookups
  • Supports searching and exporting logs
  • Supports customizing the amount of system resources used by DNS activities:
    • Maximum cache size
    • Maximum cache TTL (Time-to-live)
    • Maximum number of recursive clients
    • Maximum number of TCP connections
    • Maximum log size


  • For Synology Directory Server's zones, access control for slave zone notifications is integrated to that of zone transfer limitation
  • Listening on IP address changes of network interfaces only triggers updates of the default domain name in Synology Directory Server's zones