SRV record lookup

SRV records advertise which host serves a given service on a given port — used by SIP, XMPP, LDAP, Kerberos, Microsoft AD, and Matrix. Format: `_service._proto.<domain>`.

intermediate SRV

How to look it up

Four ways to query — pick by what's available on your machine.

dig (XMPP)dig SRV _xmpp-server._tcp.example.com +short

dig (LDAP)dig SRV _ldap._tcp.example.com +short

dotdigdotdig srv _xmpp-server._tcp.example.com

Sample response

10 5 5269 xmpp.example.com.

Format

Format: `<priority> <weight> <port> <target>.`. Priority lower = preferred. Weight = tiebreaker among same priority (proportional). Target must point to A/AAAA, NOT CNAME.

Common pitfalls

SRV target must be a hostname (A/AAAA), not a CNAME — same rule as MX. Many clients fail silently with CNAME targets.
Service prefix is hardcoded per protocol. Get one wrong (e.g. `_xmpp._tcp` vs `_xmpp-server._tcp`) and the entire SRV is invisible to the client.
Priority + weight combination is per-CHURCH — DNS doesn't track which servers are healthy. Health checks belong in the application layer.

Why it matters for security

security relevance SRV records expose your internal service infrastructure. Large enterprises hide critical SRV (Active Directory) behind split-horizon DNS to prevent reconnaissance.

Use cases

Discovering Active Directory domain controllers
Federating XMPP / Matrix services
SIP softphone provisioning
Kerberos KDC discovery

Look up DNS without flag soup

dotdig is a friendly DNS resolver — formatted output, custom resolver support, DNSSEC validation. Zero-config alternative to dig.

Open dotdig

Related DNS lookups

TXT · MX · NS · TXT (DMARC)