SRV records allow applications to locate services by providing the address and port information required. They also allow the load to be shared among several different servers using the priority and weight values.
There are six configurable components of an SRV record, and they must be defined at the point of creation. You can add SRV records in the DNS Management section of your Domain Control Panel.
The six configurable components:
- Service: The symbolic name of the desired service. Select from a list of predefined services, or enter your own.
- Protocol: The transport protocol of the service, either UDP or TCP.
- Server: The canonical hostname of the machine providing the server. You will need a trailing “.” to make this correctly formed
- Port: The TCP or UDP port for this service – this is auto-completed for predefined services.
- Priority: The priority of the target server. As with MX records, a lower value implies greater preference. Records with the lowest priority value will be used first, then falling back to other records if these fail.
- Weight: Relative weighting of records with the same priority value. Clients will query targets in proportion to their weight (for example, a record with a weight of 2 will receive twice as much traffic as a record with a weight of 1).
Complete SRV records take the following format, with the configurable fields in bold:
_Service._Protocol.Domain.com TTL IN SRV Priority Weight Port Server
And as an example:
_http._tcp.your-domain.com. 86400 IN SRV 0.5 80 www.your-domain.com