Glossary
DNS RECORDS

SRV Record

Service location record — advertises the hostname and port for a specific service on a domain. Used by SIP, XMPP, LDAP, Matrix, and Minecraft.

SRV record (Service, RFC 2782) advertises the hostname, port, priority, and weight for a specific service on a domain — solving what MX does for mail but for any service.

Record Format

_service._proto.name.  TTL  IN  SRV  priority weight port target

Real example — SIP over UDP for example.com:

_sip._udp.example.com.  86400  IN  SRV  10  60  5060  sip1.example.com.
_sip._udp.example.com.  86400  IN  SRV  10  40  5060  sip2.example.com.
_sip._udp.example.com.  86400  IN  SRV  20  0   5060  backup.example.com.

Fields

  • priority — lower = tried first
  • weight — load balancing within same priority (60% / 40% here)
  • port — service port on the target
  • target — the hostname to connect to

Who Uses SRV

  • XMPP / Matrix — federation server discovery
  • SIP — voice / video call routing
  • LDAP / Kerberos — Active Directory service discovery
  • Minecraft — server discovery for players
  • Custom microservices — internal service discovery for on-prem Kubernetes

Common Miss

Publishing SRV records for services whose clients don’t support SRV lookup (like HTTP browsers). Most web clients ignore SRV entirely — they hit A/AAAA + hardcoded ports (80, 443). SRV only helps if the client is coded to query it.

Check the MX record glossary entry, the A record glossary entry, and browse every major DNS record type.

← All terms Learning hub →