Service Record (SRV)
Specifies the hostname and port of servers for specific protocols and services.
Standards: RFC 2782
What is a DNS SRV record?
SRV (Service) records allow services to advertise their location (hostname + port + priority + weight) in DNS. Clients that support SRV can auto-discover where to connect without hardcoded configuration. SRV records are used by SIP (VoIP), XMPP (chat), Microsoft Exchange autodiscover, Minecraft servers, and Kubernetes. The record name format is: _service._proto.name (e.g. _sip._tcp.example.com). Priority and weight control load balancing: lower priority is preferred; equal-priority records are weighted proportionally. If no SRV record exists for a service, clients typically fall back to port defaults or manual configuration.
Record Structure
| Field | Description |
|---|---|
| Name | _service._proto.name, e.g. _sip._tcp.example.com |
| TTL | Time to live in seconds |
| Class | IN |
| Type | SRV |
| Priority | Lower value = higher priority |
| Weight | Load-balancing weight among same-priority records |
| Port | TCP/UDP port the service listens on |
| Target | FQDN of the host providing the service |
Examples
_sip._tcp.example.com. 3600 IN SRV 10 60 5060 sipserver.example.com.
_xmpp-client._tcp.example.com. 3600 IN SRV 5 0 5222 xmpp.example.com.
_minecraft._tcp.example.com. 30 IN SRV 0 5 25565 mc.example.com.
Common Issues & Fixes
SRV lookup returns no results
The client cannot auto-discover the service endpoint.
✓ Fix: Verify the SRV record name follows _service._proto.domain format exactly. Use the DNS Lookup tool with type=SRV.