What is a DNS SRV record?

An SRV record, which stands for "Service Record," is a specific type of DNS record used to provide information about the location of a specific service within a domain. These records are often used in situations where multiple services are available on different servers within the same domain, and they help route requests to the correct server for a particular service.

An SRV record contains the following information:

1. Service: This indicates which service is offered, such as "ldap" for Lightweight Directory Access Protocol, "http" for HTTP websites, "smtp" for e-mail and many others.
2. Protocol: Specifies the protocol used for the service, such as "tcp" or "udp."
3. Priority: This indicates which server has priority when multiple servers are available for the same service. Lower numbers have higher priority.
4. Weight: If there are multiple servers with the same priority, the weight is used to distribute the load. Servers with a higher weight receive a larger share of requests.
5. Port: This is the port on which the service is available. Each protocol usually has a default port number (e.g., 80 for HTTP, 25 for SMTP).
6. Target domain name: This is the domain name of the server on which the service is available.

With this information, clients (such as Web browsers or e-mail clients) can find the correct server and connect to the desired service within a domain.