diff --git a/tests/scripts/thread-cert/Cert_5_6_06_NetworkDataExpiration.py b/tests/scripts/thread-cert/Cert_5_6_06_NetworkDataExpiration.py
index b6c15a934..b557f0296 100755
--- a/tests/scripts/thread-cert/Cert_5_6_06_NetworkDataExpiration.py
+++ b/tests/scripts/thread-cert/Cert_5_6_06_NetworkDataExpiration.py
@@ -162,7 +162,9 @@ class Cert_5_6_6_NetworkDataExpiration(thread_cert.TestCase):
 
         # Step 5: The DUT MUST send a multicast MLE Data Response with
         # the new network information collected from Router_1
-        _lpkts.filter_mle_cmd(MLE_DATA_RESPONSE).must_next().must_verify(
+        _lpkts_med = _lpkts.copy()
+        _lpkts_sed = _lpkts.copy()
+        _lpkts.filter_LLANMA().filter_mle_cmd(MLE_DATA_RESPONSE).must_next().must_verify(
             lambda p: {
                 NWD_SERVICE_TLV, NWD_PREFIX_TLV, NWD_BORDER_ROUTER_TLV, NWD_6LOWPAN_ID_TLV, NWD_PREFIX_TLV,
                 NWD_BORDER_ROUTER_TLV, NWD_6LOWPAN_ID_TLV, NWD_PREFIX_TLV, NWD_BORDER_ROUTER_TLV, NWD_6LOWPAN_ID_TLV
@@ -170,8 +172,6 @@ class Cert_5_6_6_NetworkDataExpiration(thread_cert.TestCase):
                 Ipv6Addr('2001:2:0:1::'), Ipv6Addr('2001:2:0:2::'),
                 Ipv6Addr('2001:2:0:3::')
             } == set(p.thread_nwd.tlv.prefix) and p.thread_nwd.tlv.stable == [0, 1, 1, 1, 0, 0, 0, 1, 1, 1])
-        _lpkts_med = _lpkts.copy()
-        _lpkts_sed = _lpkts.copy()
 
         # Step 7: The DUT MUST send a unicast MLE Child Update Response to MED_1
         _lpkts_med.filter_wpan_dst64(MED).filter_mle_cmd(MLE_CHILD_UPDATE_RESPONSE).must_next().must_verify(
@@ -196,31 +196,30 @@ class Cert_5_6_6_NetworkDataExpiration(thread_cert.TestCase):
         # from Network Data TLV after Router_1 power off
         # Step 13: The DUT MUST multicast a MLE Data Response with the
         # new network information
-        _lpkts.filter_mle_cmd(MLE_DATA_RESPONSE).filter_ipv6_dst(LINK_LOCAL_ALL_NODES_MULTICAST_ADDRESS).must_next(
-        ).must_verify(
+        _lpkts.filter_LLANMA().filter_mle_cmd(MLE_DATA_RESPONSE).filter_ipv6_dst(
+            LINK_LOCAL_ALL_NODES_MULTICAST_ADDRESS
+        ).must_next().must_verify(
             lambda p: {
                 NWD_SERVICE_TLV, NWD_PREFIX_TLV, NWD_BORDER_ROUTER_TLV, NWD_6LOWPAN_ID_TLV, NWD_PREFIX_TLV,
                 NWD_BORDER_ROUTER_TLV, NWD_6LOWPAN_ID_TLV, NWD_PREFIX_TLV, NWD_BORDER_ROUTER_TLV, NWD_6LOWPAN_ID_TLV
             } == set(p.thread_nwd.tlv.type) and
             {Ipv6Addr('2001:2:0:1::'), Ipv6Addr('2001:2:0:2::'),
-             Ipv6Addr('2001:2:0:3::')} == set(p.thread_nwd.tlv.prefix) and p.mle.tlv.leader_data.data_version == _pkt.
-            mle.tlv.leader_data.data_version + 1 and p.mle.tlv.leader_data.stable_data_version == _pkt.mle.tlv.
-            leader_data.stable_data_version + 1)
-
-        _lpkts_med = _lpkts.copy()
-        _lpkts_sed = _lpkts.copy()
+             Ipv6Addr('2001:2:0:3::')} == set(p.thread_nwd.tlv.prefix) and p.mle.tlv.leader_data.data_version ==
+            (_pkt.mle.tlv.leader_data.data_version + 1) % 256 and p.mle.tlv.leader_data.stable_data_version ==
+            (_pkt.mle.tlv.leader_data.stable_data_version + 1) % 256)
 
         # Step 15: The DUT MUST send a unicast MLE Child Update Response to MED_1
         _lpkts_med.filter_mle_cmd(MLE_CHILD_UPDATE_RESPONSE).filter_wpan_dst64(MED).must_next().must_verify(
-            lambda p: {SOURCE_ADDRESS_TLV, MODE_TLV, LEADER_DATA_TLV, ADDRESS_REGISTRATION_TLV} < set(
-                p.mle.tlv.type) and p.mle.tlv.leader_data.data_version == _pkt.mle.tlv.leader_data.data_version + 1 and
-            p.mle.tlv.leader_data.stable_data_version == _pkt.mle.tlv.leader_data.stable_data_version + 1)
+            lambda p: {SOURCE_ADDRESS_TLV, MODE_TLV, LEADER_DATA_TLV, ADDRESS_REGISTRATION_TLV} < set(p.mle.tlv.type)
+            and p.mle.tlv.leader_data.data_version == (_pkt.mle.tlv.leader_data.data_version + 1) % 256 and p.mle.tlv.
+            leader_data.stable_data_version == (_pkt.mle.tlv.leader_data.stable_data_version + 1) % 256)
 
         # Step 16: The DUT MUST send a unicast MLE Child Update Request to SED_1
         _lpkts_sed.filter_mle_cmd(MLE_CHILD_UPDATE_REQUEST).filter_wpan_dst64(SED).must_next().must_verify(
             lambda p: {SOURCE_ADDRESS_TLV, LEADER_DATA_TLV, NETWORK_DATA_TLV, ACTIVE_TIMESTAMP_TLV} == set(
-                p.mle.tlv.type) and p.mle.tlv.leader_data.data_version == _pkt.mle.tlv.leader_data.data_version + 1 and
-            p.mle.tlv.leader_data.stable_data_version == _pkt.mle.tlv.leader_data.stable_data_version + 1)
+                p.mle.tlv.type) and p.mle.tlv.leader_data.data_version ==
+            (_pkt.mle.tlv.leader_data.data_version + 1) % 256 and p.mle.tlv.leader_data.stable_data_version ==
+            (_pkt.mle.tlv.leader_data.stable_data_version + 1) % 256)
 
         # Step 18: The DUT MUST send a unicast MLE Child Update Response to SED_1
         _lpkts_sed.filter_mle_cmd(MLE_CHILD_UPDATE_RESPONSE).filter_wpan_dst64(SED).must_next().must_verify(