diff --git a/lib/dns/include/dns/name.h b/lib/dns/include/dns/name.h
index 01f776debb..1cf7129b81 100644
--- a/lib/dns/include/dns/name.h
+++ b/lib/dns/include/dns/name.h
@@ -1298,10 +1298,17 @@ dns_name_isula(const dns_name_t *owner);
 
 bool
 dns_name_istat(const dns_name_t *name);
-/*
+/*%<
  * Determine if 'name' is a potential 'trust-anchor-telemetry' name.
  */
 
+bool
+dns_name_isdnssvcb(const dns_name_t *name);
+/*%<
+ * Determine if 'name' is a dns service name,
+ * i.e. it starts with and optional _port label followed by a _dns label.
+ */
+
 ISC_LANG_ENDDECLS
 
 /*
diff --git a/lib/dns/name.c b/lib/dns/name.c
index b8a9ec46f0..96586def8c 100644
--- a/lib/dns/name.c
+++ b/lib/dns/name.c
@@ -2376,3 +2376,57 @@ dns_name_istat(const dns_name_t *name) {
 	}
 	return (true);
 }
+
+bool
+dns_name_isdnssvcb(const dns_name_t *name) {
+	unsigned char len, len1;
+	const unsigned char *ndata;
+
+	REQUIRE(VALID_NAME(name));
+
+	if (name->labels < 1 || name->length < 5) {
+		return (false);
+	}
+
+	ndata = name->ndata;
+	len = len1 = ndata[0];
+	INSIST(len <= name->length);
+	ndata++;
+
+	if (len < 2 || ndata[0] != '_') {
+		return (false);
+	}
+	if (isdigit(ndata[1]) && name->labels > 1) {
+		char buf[sizeof("65000")];
+		long port;
+		char *endp;
+
+		/*
+		 * Do we have a valid _port label?
+		 */
+		if (len > 6U || (ndata[1] == '0' && len != 2)) {
+			return (false);
+		}
+		memcpy(buf, ndata + 1, len - 1);
+		buf[len - 1] = 0;
+		port = strtol(buf, &endp, 10);
+		if (*endp != 0 || port < 0 || port > 0xffff) {
+			return (false);
+		}
+
+		/*
+		 * Move to next label.
+		 */
+		ndata += len;
+		INSIST(len1 + 1U < name->length);
+		len = *ndata;
+		INSIST(len + len1 + 1U <= name->length);
+		ndata++;
+	}
+
+	if (len == 4U && strncasecmp((const char *)ndata, "_dns", 4) == 0) {
+		return (true);
+	}
+
+	return (false);
+}