diff --git a/tests/TestSuite_external_memory.py b/tests/TestSuite_external_memory.py
index f68a9a6..2f862fa 100644
--- a/tests/TestSuite_external_memory.py
+++ b/tests/TestSuite_external_memory.py
@@ -40,6 +40,7 @@ import time
 
 import framework.utils as utils
 from framework.test_case import TestCase
+from framework.pmd_output import PmdOutput
 
 
 class TestExternalMemory(TestCase):
@@ -49,7 +50,7 @@ class TestExternalMemory(TestCase):
         """
         self.dut_ports = self.dut.get_ports(self.nic)
         self.verify(len(self.dut_ports) >= 2, "Insufficient ports")
-
+        self.pmdout = PmdOutput(self.dut)
         self.app_testpmd_path = self.dut.apps_name['test-pmd']
 
     def set_up(self):
@@ -134,6 +135,7 @@ class TestExternalMemory(TestCase):
 
     def verifier_result(self):
         self.dut.send_expect("start", "testpmd>",10)
+        self.pmdout.wait_link_status_up(self.dut_ports[0])
         self.scapy_send_packet(20)
         out = self.dut.send_expect("stop", "testpmd>", 10)
 
diff --git a/tests/TestSuite_mtu_update.py b/tests/TestSuite_mtu_update.py
index ad13a8a..f16eb8e 100644
--- a/tests/TestSuite_mtu_update.py
+++ b/tests/TestSuite_mtu_update.py
@@ -235,6 +235,7 @@ class TestMtuUpdate(TestCase):
         self.exec("port start all")
         self.exec("set fwd mac")
         self.exec("start")
+        self.pmdout.wait_link_status_up(self.dut_ports[0])
         """
         On 1G NICs, when the jubmo frame MTU set > 1500, the software adjust it to MTU+4.
         """
diff --git a/tests/TestSuite_scatter.py b/tests/TestSuite_scatter.py
index 85312c5..499c0ab 100644
--- a/tests/TestSuite_scatter.py
+++ b/tests/TestSuite_scatter.py
@@ -110,6 +110,7 @@ class TestScatter(TestCase):
 
         self.dut.send_expect("set fwd mac", "testpmd> ", 120)
         self.dut.send_expect("start", "testpmd> ")
+        self.pmdout.wait_link_status_up(self.port)
 
         for offset in [-1, 0, 1, 4, 5]:
             ret = self.scatter_pktgen_send_packet(self.mbsize + offset)
diff --git a/tests/TestSuite_vxlan.py b/tests/TestSuite_vxlan.py
index 1442578..9605c89 100644
--- a/tests/TestSuite_vxlan.py
+++ b/tests/TestSuite_vxlan.py
@@ -472,8 +472,8 @@ class TestVxlan(TestCase):
         config.outer_mac_dst = self.dut_port_mac
         config.create_pcap()
         self.dut.send_expect("start", "testpmd>", 10)
+        self.pmdout.wait_link_status_up(self.dut_port)
         config.send_pcap(self.tester_iface)
-
         # check whether detect vxlan type
         out = self.dut.get_session_output(timeout=2)
         print(out)
@@ -572,6 +572,7 @@ class TestVxlan(TestCase):
         # send vxlan packet
         config.create_pcap()
         self.dut.send_expect("start", "testpmd>", 10)
+        self.pmdout.wait_link_status_up(self.dut_port)
         config.send_pcap(self.tester_iface)
         out = self.dut.get_session_output(timeout=2)
         print(out)
@@ -606,7 +607,7 @@ class TestVxlan(TestCase):
         self.dut.send_expect("set verbose 1", "testpmd>", 10)
         self.enable_vxlan(self.dut_port)
         self.enable_vxlan(self.recv_port)
-
+        self.pmdout.wait_link_status_up(self.dut_port)
         # check normal packet
         self.send_and_detect(outer_udp_dst=1234)
         # check vxlan + UDP inner packet
@@ -642,7 +643,7 @@ class TestVxlan(TestCase):
         self.dut.send_expect("set verbose 1", "testpmd>", 10)
         self.enable_vxlan(self.dut_port)
         self.enable_vxlan(self.recv_port)
-
+        self.pmdout.wait_link_status_up(self.dut_port)
         # check normal ipv6 packet
         self.send_and_detect(outer_ip6_src="FE80:0:0:0:0:0:0:0",
                              outer_ip6_dst="FE80:0:0:0:0:0:0:1",
@@ -692,7 +693,7 @@ class TestVxlan(TestCase):
 
         self.enable_vxlan(self.dut_port)
         self.enable_vxlan(self.recv_port)
-
+        self.pmdout.wait_link_status_up(self.dut_port)
         # check normal packet + ip checksum invalid
         self.send_and_check(outer_ip_invalid=1, outer_udp_dst=1234)
         # check vxlan packet + inner ip checksum invalid
@@ -754,6 +755,7 @@ class TestVxlan(TestCase):
         self.dut.send_expect("set fwd csum", "testpmd>", 10)
         self.csum_set_type('outer-ip', self.recv_port)
         self.csum_set_type('udp', self.recv_port)
+        self.csum_set_type('outer-udp', self.recv_port)
         self.csum_set_type('tcp', self.recv_port)
         self.csum_set_type('sctp', self.recv_port)
         self.dut.send_expect("csum parse-tunnel on %d" %
@@ -761,7 +763,7 @@ class TestVxlan(TestCase):
 
         self.enable_vxlan(self.dut_port)
         self.enable_vxlan(self.recv_port)
-
+        self.pmdout.wait_link_status_up(self.dut_port)
         # check normal ipv6 packet
         self.send_and_check(outer_ip6_src="FE80:0:0:0:0:0:0:0",
                             outer_ip6_dst="FE80:0:0:0:0:0:0:1")
@@ -821,7 +823,7 @@ class TestVxlan(TestCase):
         self.dut.send_expect("set verbose 1", "testpmd>", 10)
         self.enable_vxlan(self.dut_port)
         self.enable_vxlan(self.recv_port)
-
+        self.pmdout.wait_link_status_up(self.dut_port)
         config = VxlanTestConfig(self)
         config_vlan = VxlanTestConfig(self, inner_vlan=1)
         config.outer_mac_dst = self.dut_port_mac
@@ -892,6 +894,7 @@ class TestVxlan(TestCase):
 
         self.enable_vxlan(self.dut_port)
         self.enable_vxlan(self.recv_port)
+        self.pmdout.wait_link_status_up(self.dut_port)
         rule = 'flow create {} ingress pattern eth / ipv4 / udp / vxlan vni is {} / eth dst is {} / end actions pf ' \
                '/ queue index {} / end'.format(self.dut_port,
                                                config.vni,
@@ -1048,7 +1051,7 @@ class TestVxlan(TestCase):
 
             self.dut.send_expect("set fwd io", "testpmd>", 10)
             self.dut.send_expect("start", "testpmd>", 10)
-
+            self.pmdout.wait_link_status_up(self.dut_port)
             if BIDIRECT:
                 wirespeed = self.wirespeed(self.nic, PACKET_LEN, 2)
             else:
@@ -1131,6 +1134,7 @@ class TestVxlan(TestCase):
             self.dut.send_expect("set fwd csum", "testpmd>", 10)
             self.enable_vxlan(self.dut_port)
             self.enable_vxlan(self.recv_port)
+            self.pmdout.wait_link_status_up(self.dut_port)
 
             # redirect flow to another queue by tunnel filter
             rule_config = {
