Which DNS records specify the location of a service along with its protocol and port?

Which DNS records specify the location of a service along with its protocol and port?

• A. A Records
• B. PTR Records
• C. SRV Records
• D. MX Records

Answer: (C)

SRV records are used to locate a service in DNS and specify how to reach it. They name the service together with the protocol (for example, _sip._tcp or _http._tcp) and include the port number where the service runs, plus the target host to contact. This lets clients discover not only which server provides a service but also the exact port to connect to. By contrast, A records only map a hostname to an IP address, MX records designate mail servers for a domain, and PTR records map an IP address back to a hostname. For example, an SRV record might indicate that the SIP service for a domain is available via sipserver.example.com on port 5060.

SRV records are used to locate a service in DNS and specify how to reach it. They name the service together with the protocol (for example, _sip._tcp or _http._tcp) and include the port number where the service runs, plus the target host to contact. This lets clients discover not only which server provides a service but also the exact port to connect to. By contrast, A records only map a hostname to an IP address, MX records designate mail servers for a domain, and PTR records map an IP address back to a hostname. For example, an SRV record might indicate that the SIP service for a domain is available via sipserver.example.com on port 5060.