Skip to main content

DNS settings

DNS settings determine which servers and services belong to a domain - for example, which website is loaded or where emails are delivered. A DNS zone file contains various entry types ("record types"), each serving a specific purpose.

Basic principle of DNS​

  • The Domain Name System, or DNS for short, translates human-readable domain names like example.com into IP addresses at which servers can be reached on the internet.
  • Each DNS record typically consists of a name (e.g. www), a type (e.g. A), content/value (e.g. an IP address) and a validity period (TTL, time to live).
  • The complete set of records for a domain is called a DNS zone and is stored on the authoritative name servers of that domain.

Important basic records​

  • A record: Maps a hostname to an IPv4 address, e.g. "example.com → 1.2.3.4".
  • AAAA record: Same as an A record, but points to an IPv6 address, e.g. "example.com → 2001:db8::1".
  • CNAME record: Defines an alias, e.g. "blog.example.com → www.example.com", pointing to another hostname rather than directly to an IP address. If the IP address of www.example.com changes in this example, the change automatically applies to blog.example.com as well.
  • MX record: Specifies which mail servers accept emails for a domain, e.g. "example.com → mail.example.com", usually with a priority value (e.g. 10 for the primary and 20 for a backup server).
  • TXT record: Contains freely definable text information, such as SPF, DKIM or DMARC data for spam protection and email authentication. It can also be used to verify domain ownership.
  • SPF (as TXT type): Defines which servers are allowed to send emails on behalf of the domain; technically usually implemented as a special TXT record.

Infrastructure records​

  • NS record: Specifies which name servers are responsible for a zone, e.g. "example.com → ns1.example.com", and is required for other DNS servers to correctly resolve the domain.
  • SOA record: The "Start of Authority" record contains basic zone data, such as the primary name server, the email address of the person responsible for the zone and update intervals.
  • CAA record: Specifies which certificate authorities (CAs) are allowed to issue TLS/SSL certificates for a domain.
  • SRV record: Describes the host and port on which a specific service is available, e.g. for SIP, XMPP or Microsoft services, including priority and weight.

Notes on settings​

  • You usually make changes in the client area of your domain provider, in the DNS or name server section. There you can create new records or update existing ones.
  • After saving, it often takes anywhere from a few minutes to 48 hours for new DNS records to become visible worldwide due to caching and TTL settings.
Last updated on