SRV-Records (location of service)

SRV-records are used to specify the location of a service.

They are used in connection with different directory servers such as LDAP (Lightweight Directory Access Protocol), and Windows Active Directory, and more recently with SIP servers (see

The SRV record identification (record name) is made of of 3 parts:

  • Service: Most internet services are defined in RFC1700 (page 15).

  • Protocol: Generally TCP or UDP, but other values are also valid.

  • Domain name.

The "service location" is specified through a priority, weight, port and target:

  • Priority is a preference number used when more servers are providing the same service (lower numbers are tried first).

  • Weight is used for advanced load balancing.

  • Port is the TCP/UDP port number on the server that provides this service.

  • Target is the domain name of the server (referencing an A-record or AAAA-record).

To create a new SRV-record, right-click a zone in the left list in the DNS Records window, and select "Other new record" from the pop-up menu.

This record type is defined in RFC2782.

Note: While this record type could potentially have been used by web-browser software (to locate web-servers), this was never implemented by any major browsers. Instead browsers have recently (2021) started supporting the HTTPS record-type which provdides similar functionality specifically for web-sites.

8 Oct 2019 15:07 UTC
Sentense: "Protocol: Generally TCP or UDP, but also values are also valid.". Do you mean that also numerical values are accepted besides typing "TCP" or "UPD"?
JH Software
17 Dec 2019 23:37 UTC
JH Software
This would most likely be letters (not numbers) - and almost always either UDP or TCP - but this depends entirely on the application using the service.
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