--- title: Free SRV Record Lookup description: Look up service records like _sip._tls or _xmpp-server._tcp — target host, port, priority and weight for each SRV entry. Verify SIP, XMPP, LDAP, Minecraft and Microsoft 365 service discovery, and find the SRV that points at a port nothing listens on. canonical: https://watchfor.io/srv-record-lookup --- [Back to all free tools](/free-tools) # SRV Record Lookup Look up service records like _sip._tls or _xmpp-server._tcp — target host, port, priority and weight for each SRV entry. Verify SIP, XMPP, LDAP, Minecraft and Microsoft 365 service discovery, and find the SRV that points at a port nothing listens on. Result No result yet Enter the inputs above and press Run. Results appear here in a moment. Monitor this 24/7 — get alerts on the first failure. [Start free](/auth/sign-up) Only run these tools against systems you own or are authorized to test. Using them to scan or probe systems without permission violates our [Terms](/legal/terms). ## What is SRV Record Lookup ? SRV records tell clients where a service lives — which host, which port, and in what order to try them. Instead of hard-coding sip.example.com:5061 , a SIP phone asks DNS for _sip._tls.example.com and gets back one or more targets with priority, weight and port. XMPP, LDAP and Active Directory, Kerberos, Minecraft servers, Microsoft 365 federation and Teams, and CalDAV/CardDAV autodiscovery all rely on them. This tool looks up the SRV records for any service name and shows each target with its priority, weight, port and TTL. Use it to verify the service records a provider asked you to add, to see why a client connects to the wrong host or port, and to confirm the target names themselves resolve. ## How it works SRV lookups differ from other records in one way — the name is structured: - 1 Build the service name — _._. : _sip._tls.example.com , _xmpp-server._tcp.example.com , _ldap._tcp.dc._msdcs.corp.example.com , _minecraft._tcp.example.com . Both underscores are required; the service and protocol names come from the IANA registry or the vendor's instructions. - 2 Query `QTYPE=SRV` — The answer is one record per target: priority, weight, port, target hostname. - 3 Resolve the target — Each target must have an A or AAAA record (never a CNAME, per RFC 2782). The lookup shows the targets; an A lookup on each confirms they exist. Clients try the lowest priority first and pick among equal priorities in proportion to weight — SRV is a small load balancer built into DNS. ## When you'd use it ### Microsoft 365, Teams and Skype federation Microsoft's setup asks for _sip._tls and _sipfederationtls._tcp records with specific targets and ports. If the admin center reports them as missing, look them up: usually the name was entered without the underscores or with the domain appended twice. ### Running a game or chat server on a non-standard port A Minecraft server on port 25566 can be reached as play.example.com without a port if _minecraft._tcp.play.example.com says so. When players can't connect, the SRV target or port is wrong. ### Active Directory and LDAP discovery Domain-joined machines find domain controllers through _ldap._tcp and _kerberos._tcp SRV records. A missing or stale one explains logon delays after a DC was replaced. ### XMPP and SIP interoperability Other servers find yours through _xmpp-server._tcp or _sip._udp . If federation only works in one direction, the other side's SRV lookup for your domain is the first thing to check. ## Reading the result ### Priority Lower is tried first. Put the primary server at 10 and a backup at 20 ; clients use the backup only when every 10 target fails. ### Weight Among targets with the same priority, the share of clients each gets. 60 and 40 split traffic 60/40; 0 means "only if nothing else has weight". ### Port The port the service actually listens on. This is the whole point of SRV: it doesn't have to be the protocol's default. ### Target A hostname with A/AAAA records. A single dot ( . ) as the target means the service is explicitly not available on this domain. ## Check it yourself dig SRV _sip._tls.example.com @1.1.1.1 +noall +answer The answer fields are, in order: priority, weight, port, target. ## Common pitfalls ### Underscores dropped by the DNS UI Some providers' forms strip or reject leading underscores; others need the record type set to SRV before the name field accepts them. The lookup returning NXDOMAIN for the exact name is the tell. ### Target is a CNAME RFC 2782 requires an A/AAAA target. Some clients follow the alias; many don't. Point the SRV at the real host. ### Assuming web browsers use SRV They don't — HTTP never adopted SRV. Browsers use A/AAAA and, newly, HTTPS records (type 65). SRV is for the protocols listed above, not for websites. ## Run SRV Record Lookup on every change, not just once. Get alerts the moment something breaks — across HTTP, DNS, SSL, RDAP, ping, blacklist and more. Free forever for 10 monitors. No card. [Start free](/auth/sign-up) ## Frequently asked questions What does an SRV record look like? _sip._tls.example.com. 3600 IN SRV 100 1 443 sipdir.online.lync.com. — name, TTL, class, type, then priority 100, weight 1, port 443, target hostname. What are the SRV records for Microsoft 365 / Teams? _sip._tls.example.com → priority 100, weight 1, port 443, target sipdir.online.lync.com ; and _sipfederationtls._tcp.example.com → 100, 1, 5061, sipfed.online.lync.com . Microsoft's admin center shows the current values. How does priority differ from weight? Priority is strict ordering (lowest first, others only as failover). Weight is proportional sharing among targets that have the same priority. Can SRV records point to a different domain? Yes — the target can be any hostname, including a provider's. That's how hosted SIP and XMPP services work. Do SRV records work for HTTP or HTTPS? No browser uses them. For web endpoints, look at HTTPS/SVCB records (RFC 9460), which the DNS Lookup tool can query with record type HTTPS . ## Related dns tools - [DNS LookupResolve A, AAAA, MX, TXT, NS, SOA, CNAME, PTR, CAA, SRV records for any domain.](/dns-checker) - [DNS PropagationCheck how a DNS record looks from every prober region simultaneously — spot stale anycast nodes and propagation gaps on a world map.](/dns-propagation-checker) - [Whois LookupModern RDAP-based domain registration lookup: registrar, expiry, nameservers, status flags.](/whois-lookup) - [A Record LookupFind the IPv4 address a domain resolves to — every A record with its TTL, from the resolver of your choice. Spot a stale IP after a migration, a missing record behind a 'site can't be reached', or a round-robin set that is one address short.](/a-record-lookup) --- Canonical page: https://watchfor.io/srv-record-lookup · Site guide: https://watchfor.io/llms.txt