SRV Record Lookup
Find the host and port a named service is published on, with priority and weight.
Your input is used for this one lookup only. It is not logged or stored.
What is an SRV record?
An SRV record publishes the host and port for a named service, so clients can find it without a hardcoded port number. The name follows a fixed pattern — _service._protocol.domain — and the record adds priority and weight so a service can be spread across several hosts.
Fields in an SRV record
| Field | Meaning |
|---|---|
| Priority | Lower is tried first, like MX preference. |
| Weight | Relative share of traffic among records with the same priority. Higher takes proportionally more. |
| Port | TCP or UDP port the service listens on. |
| Target | Hostname of the server. It must have its own A or AAAA record. |
How to read the results
Read priority first, then weight. Clients pick the lowest priority available, and among equals distribute by weight — a record with weight 20 gets roughly twice the traffic of one with weight 10. A target of . means the service is explicitly not available at this domain.
Rules worth knowing
- The query name must be
_service._protocol.domain, for example_sip._tcp.example.com. Both underscores are required. - The target must be a hostname with A/AAAA records — not an IP address and not a CNAME.
- A target of
.declares the service unavailable. - The client has to support SRV for the record to matter. Browsers do not use SRV for ordinary HTTP.
Common problems
| What you see | Usual cause |
|---|---|
| No records | Nine times out of ten the name is missing its underscores or the protocol label. Query _service._tcp.domain, not service.domain. |
| The client ignores the record | That protocol does not use SRV. HTTP in browsers, for instance, does not. |
| Traffic is unevenly split | That is what weight does. Equal split needs equal weights at the same priority. |
| Connection refused | DNS is fine — the port in the record is not open on the target host. Check the service itself. |
Look up another record type
Each record type has its own page with the same explanation of its fields, or use the full DNS Lookup to query every common type at once.
Most often looked up alongside SRV: A Record Lookup , MX Record Lookup , TXT Record Lookup .
Data source: Public DNS-over-HTTPS resolvers. Queries go to the selected public resolver; results reflect that resolver’s cache. Learn about our data sources →
Frequently asked questions
How do I look up an SRV record?
_sip._tcp.example.com. Querying the bare domain returns nothing, which is the most common reason people think a record is missing.