diff --git a/agents/libdns_test.go b/agents/libdns_test.go
index bef6861e3..e6665054a 100644
--- a/agents/libdns_test.go
+++ b/agents/libdns_test.go
@@ -18,7 +18,14 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>
 
 package agents
 
-import "testing"
+import (
+	"reflect"
+	"testing"
+
+	"github.com/cgrates/cgrates/config"
+	"github.com/cgrates/cgrates/utils"
+	"github.com/cgrates/dns"
+)
 
 func TestE164FromNAPTR(t *testing.T) {
 	if e164, err := e164FromNAPTR("8.7.6.5.4.3.2.1.0.1.6.e164.arpa."); err != nil {
@@ -27,3 +34,265 @@ func TestE164FromNAPTR(t *testing.T) {
 		t.Errorf("received: <%s>", e164)
 	}
 }
+
+func TestAppendDNSAnswerTypeNAPTR(t *testing.T) {
+	m := new(dns.Msg)
+	m.SetQuestion("3.6.9.4.7.1.7.1.5.6.8.9.4.e164.arpa.", dns.TypeNAPTR)
+	if err := appendDNSAnswer(m); err != nil {
+		t.Error(err)
+	}
+	if len(m.Answer) != 1 {
+		t.Fatalf("Unexpected number of Answers : %+v", len(m.Answer))
+	} else if m.Answer[0].Header().Name != "3.6.9.4.7.1.7.1.5.6.8.9.4.e164.arpa." {
+		t.Errorf("expecting: <3.6.9.4.7.1.7.1.5.6.8.9.4.e164.arpa.>, received: <%+v>", m.Answer[0].Header().Name)
+	} else if m.Answer[0].Header().Rrtype != 35 {
+		t.Errorf("expecting: <35>, received: <%+v>", m.Answer[0].Header().Rrtype)
+	} else if m.Answer[0].Header().Class != dns.ClassINET {
+		t.Errorf("expecting: <%+v>, received: <%+v>", dns.ClassINET, m.Answer[0].Header().Rrtype)
+	} else if m.Answer[0].Header().Ttl != 60 {
+		t.Errorf("expecting: <60>, received: <%+v>", m.Answer[0].Header().Rrtype)
+	}
+}
+
+func TestAppendDNSAnswerTypeA(t *testing.T) {
+	m := new(dns.Msg)
+	m.SetQuestion("3.6.9.4.7.1.7.1.5.6.8.9.4.e164.arpa.", dns.TypeA)
+	if err := appendDNSAnswer(m); err != nil {
+		t.Error(err)
+	}
+	if len(m.Answer) != 1 {
+		t.Fatalf("Unexpected number of Answers : %+v", len(m.Answer))
+	} else if m.Answer[0].Header().Name != "3.6.9.4.7.1.7.1.5.6.8.9.4.e164.arpa." {
+		t.Errorf("expecting: <3.6.9.4.7.1.7.1.5.6.8.9.4.e164.arpa.>, received: <%+v>", m.Answer[0].Header().Name)
+	} else if m.Answer[0].Header().Rrtype != 1 {
+		t.Errorf("expecting: <1>, received: <%+v>", m.Answer[0].Header().Rrtype)
+	} else if m.Answer[0].Header().Class != dns.ClassINET {
+		t.Errorf("expecting: <%+v>, received: <%+v>", dns.ClassINET, m.Answer[0].Header().Rrtype)
+	} else if m.Answer[0].Header().Ttl != 60 {
+		t.Errorf("expecting: <60>, received: <%+v>", m.Answer[0].Header().Rrtype)
+	}
+}
+
+func TestAppendDNSAnswerUnexpectedType(t *testing.T) {
+	m := new(dns.Msg)
+	m.SetQuestion("3.6.9.4.7.1.7.1.5.6.8.9.4.e164.arpa.", dns.TypeAFSDB)
+	if err := appendDNSAnswer(m); err == nil || err.Error() != "unsupported DNS type: <18>" {
+		t.Error(err)
+	}
+}
+
+func TestDNSDPFieldAsInterface(t *testing.T) {
+	m := new(dns.Msg)
+	m.SetQuestion("3.6.9.4.7.1.7.1.5.6.8.9.4.e164.arpa.", dns.TypeNAPTR)
+	dp := newDNSDataProvider(m, nil)
+	expected := m.Question[0]
+	if data, err := dp.FieldAsInterface([]string{"test"}); err != nil {
+		t.Error(err)
+	} else if !reflect.DeepEqual(data, expected) {
+		t.Errorf("expecting: <%+v>, received: <%+v>", expected, data)
+	}
+}
+
+func TestDNSDPFieldAsInterfaceEmptyPath(t *testing.T) {
+	m := new(dns.Msg)
+	m.SetQuestion("3.6.9.4.7.1.7.1.5.6.8.9.4.e164.arpa.", dns.TypeNAPTR)
+	dp := newDNSDataProvider(m, nil)
+	if _, err := dp.FieldAsInterface([]string{}); err == nil ||
+		err.Error() != "empty field path" {
+		t.Error(err)
+	}
+}
+
+func TestDNSDPFieldAsInterfaceFromCache(t *testing.T) {
+	m := new(dns.Msg)
+	m.SetQuestion("3.6.9.4.7.1.7.1.5.6.8.9.4.e164.arpa.", dns.TypeNAPTR)
+	dp := newDNSDataProvider(m, nil)
+	expected := m.Question[0]
+	if data, err := dp.FieldAsInterface([]string{"test"}); err != nil {
+		t.Error(err)
+	} else if !reflect.DeepEqual(data, expected) {
+		t.Errorf("expecting: <%+v>, received: <%+v>", expected, data)
+	}
+	if data, err := dp.FieldAsInterface([]string{"test"}); err != nil {
+		t.Error(err)
+	} else if !reflect.DeepEqual(data, expected) {
+		t.Errorf("expecting: <%+v>, received: <%+v>", expected, data)
+	}
+}
+
+func TestDNSDPFieldAsString(t *testing.T) {
+	m := new(dns.Msg)
+	m.SetQuestion("3.6.9.4.7.1.7.1.5.6.8.9.4.e164.arpa.", dns.TypeNAPTR)
+	dp := newDNSDataProvider(m, nil)
+	expected := utils.ToJSON(m.Question[0])
+	if data, err := dp.FieldAsString([]string{"test"}); err != nil {
+		t.Error(err)
+	} else if !reflect.DeepEqual(data, expected) {
+		t.Errorf("expecting: <%+v>, received: <%+v>", expected, data)
+	}
+}
+
+func TestDNSDPFieldAsStringEmptyPath(t *testing.T) {
+	m := new(dns.Msg)
+	m.SetQuestion("3.6.9.4.7.1.7.1.5.6.8.9.4.e164.arpa.", dns.TypeNAPTR)
+	dp := newDNSDataProvider(m, nil)
+	if _, err := dp.FieldAsString([]string{}); err == nil ||
+		err.Error() != "empty field path" {
+		t.Error(err)
+	}
+}
+
+func TestDNSDPFieldAsStringFromCache(t *testing.T) {
+	m := new(dns.Msg)
+	m.SetQuestion("3.6.9.4.7.1.7.1.5.6.8.9.4.e164.arpa.", dns.TypeNAPTR)
+	dp := newDNSDataProvider(m, nil)
+	expected := utils.ToJSON(m.Question[0])
+	if data, err := dp.FieldAsString([]string{"test"}); err != nil {
+		t.Error(err)
+	} else if !reflect.DeepEqual(data, expected) {
+		t.Errorf("expecting: <%+v>, received: <%+v>", expected, data)
+	}
+	if data, err := dp.FieldAsString([]string{"test"}); err != nil {
+		t.Error(err)
+	} else if !reflect.DeepEqual(data, expected) {
+		t.Errorf("expecting: <%+v>, received: <%+v>", expected, data)
+	}
+}
+
+func TestUpdateDNSMsgFromNM(t *testing.T) {
+	m := new(dns.Msg)
+	m.SetQuestion("3.6.9.4.7.1.7.1.5.6.8.9.4.e164.arpa.", dns.TypeNAPTR)
+
+	nM := config.NewNavigableMap(nil)
+	itm := &config.NMItem{
+		Path: []string{},
+		Data: "Val1",
+	}
+	nM.Set([]string{"Path"}, []*config.NMItem{itm}, true, true)
+	if err := updateDNSMsgFromNM(m, nM); err == nil ||
+		err.Error() != "empty path in config item" {
+		t.Error(err)
+	}
+
+	nM = config.NewNavigableMap(nil)
+	nM.Set([]string{"Path"}, "test", true, true)
+	if err := updateDNSMsgFromNM(m, nM); err == nil ||
+		err.Error() != `cannot cast val: "test" into []*config.NMItem` {
+		t.Error(err)
+	}
+
+	nM = config.NewNavigableMap(nil)
+	itm = &config.NMItem{
+		Path: []string{utils.Rcode},
+		Data: 10,
+	}
+	nM.Set(itm.Path, []*config.NMItem{itm}, true, true)
+	if err := updateDNSMsgFromNM(m, nM); err != nil {
+		t.Error(err)
+	}
+	if m.Rcode != 10 {
+		t.Errorf("expecting: <10>, received: <%+v>", m.Rcode)
+	}
+
+	nM = config.NewNavigableMap(nil)
+	itm = &config.NMItem{
+		Path: []string{utils.Rcode},
+		Data: "RandomValue",
+	}
+	nM.Set(itm.Path, []*config.NMItem{itm}, true, true)
+	if err := updateDNSMsgFromNM(m, nM); err == nil ||
+		err.Error() != `item: <Rcode>, err: strconv.ParseInt: parsing "RandomValue": invalid syntax` {
+		t.Error(err)
+	}
+
+	nM = config.NewNavigableMap(nil)
+	itm = &config.NMItem{
+		Path: []string{utils.Order},
+		Data: "RandomValue",
+	}
+	nM.Set(itm.Path, []*config.NMItem{itm}, true, true)
+	if err := updateDNSMsgFromNM(m, nM); err == nil ||
+		err.Error() != `item: <Order>, err: strconv.ParseInt: parsing "RandomValue": invalid syntax` {
+		t.Error(err)
+	}
+
+	nM = config.NewNavigableMap(nil)
+	itm = &config.NMItem{
+		Path: []string{utils.Preference},
+		Data: "RandomValue",
+	}
+	nM.Set(itm.Path, []*config.NMItem{itm}, true, true)
+	if err := updateDNSMsgFromNM(m, nM); err == nil ||
+		err.Error() != `item: <Preference>, err: strconv.ParseInt: parsing "RandomValue": invalid syntax` {
+		t.Error(err)
+	}
+
+	m = new(dns.Msg)
+	m.SetQuestion("3.6.9.4.7.1.7.1.5.6.8.9.4.e164.arpa.", dns.TypeA)
+	nM = config.NewNavigableMap(nil)
+	itm = &config.NMItem{
+		Path: []string{utils.Order},
+		Data: 10,
+	}
+	nM.Set(itm.Path, []*config.NMItem{itm}, true, true)
+	if err := updateDNSMsgFromNM(m, nM); err == nil ||
+		err.Error() != `field <Order> only works with NAPTR` {
+		t.Error(err)
+	}
+
+	nM = config.NewNavigableMap(nil)
+	itm = &config.NMItem{
+		Path: []string{utils.Preference},
+		Data: 10,
+	}
+	nM.Set(itm.Path, []*config.NMItem{itm}, true, true)
+	if err := updateDNSMsgFromNM(m, nM); err == nil ||
+		err.Error() != `field <Preference> only works with NAPTR` {
+		t.Error(err)
+	}
+
+	nM = config.NewNavigableMap(nil)
+	itm = &config.NMItem{
+		Path: []string{utils.Flags},
+		Data: 10,
+	}
+	nM.Set(itm.Path, []*config.NMItem{itm}, true, true)
+	if err := updateDNSMsgFromNM(m, nM); err == nil ||
+		err.Error() != `field <Flags> only works with NAPTR` {
+		t.Error(err)
+	}
+
+	nM = config.NewNavigableMap(nil)
+	itm = &config.NMItem{
+		Path: []string{utils.Service},
+		Data: 10,
+	}
+	nM.Set(itm.Path, []*config.NMItem{itm}, true, true)
+	if err := updateDNSMsgFromNM(m, nM); err == nil ||
+		err.Error() != `field <Service> only works with NAPTR` {
+		t.Error(err)
+	}
+
+	nM = config.NewNavigableMap(nil)
+	itm = &config.NMItem{
+		Path: []string{utils.Regexp},
+		Data: 10,
+	}
+	nM.Set(itm.Path, []*config.NMItem{itm}, true, true)
+	if err := updateDNSMsgFromNM(m, nM); err == nil ||
+		err.Error() != `field <Regexp> only works with NAPTR` {
+		t.Error(err)
+	}
+
+	nM = config.NewNavigableMap(nil)
+	itm = &config.NMItem{
+		Path: []string{utils.Replacement},
+		Data: 10,
+	}
+	nM.Set(itm.Path, []*config.NMItem{itm}, true, true)
+	if err := updateDNSMsgFromNM(m, nM); err == nil ||
+		err.Error() != `field <Replacement> only works with NAPTR` {
+		t.Error(err)
+	}
+
+}