diff --git a/neutron_tempest_plugin/scenario/test_floatingip.py b/neutron_tempest_plugin/scenario/test_floatingip.py
index 0febce27..b253890a 100644
--- a/neutron_tempest_plugin/scenario/test_floatingip.py
+++ b/neutron_tempest_plugin/scenario/test_floatingip.py
@@ -21,6 +21,7 @@ from tempest.lib import decorators
 import testscenarios
 from testscenarios.scenarios import multiply_scenarios
 
+from neutron_lib import constants as lib_constants
 from neutron_tempest_plugin.common import ssh
 from neutron_tempest_plugin.common import utils as common_utils
 from neutron_tempest_plugin import config
@@ -58,6 +59,17 @@ class FloatingIpTestCasesMixin(object):
         else:
             cls._dest_network = cls._create_dest_network()
 
+    @classmethod
+    def _get_external_gateway(cls):
+        if CONF.network.public_network_id:
+            subnets = cls.os_admin.network_client.list_subnets(
+                network_id=CONF.network.public_network_id)
+
+            for subnet in subnets['subnets']:
+                if (subnet['gateway_ip']
+                    and subnet['ip_version'] == lib_constants.IP_VERSION_4):
+                    return subnet['gateway_ip']
+
     @classmethod
     def _create_dest_network(cls):
         network = cls.create_network()
@@ -157,3 +169,30 @@ class FloatingIpSeparateNetwork(FloatingIpTestCasesMixin,
     @decorators.idempotent_id('f18f0090-3289-4783-b956-a0f8ac511e8b')
     def test_east_west(self):
         self._test_east_west()
+
+
+class DefaultSnatToExternal(FloatingIpTestCasesMixin,
+                            base.BaseTempestTestCase):
+    same_network = True
+
+    @decorators.idempotent_id('3d73ea1a-27c6-45a9-b0f8-04a283d9d764')
+    def test_snat_external_ip(self):
+        """Check connectivity to an external IP"""
+        gateway_external_ip = self._get_external_gateway()
+
+        if not gateway_external_ip:
+            raise self.skipTest("IPv4 gateway is not configured for public "
+                                "network or public_network_id is not "
+                                "configured")
+        proxy = self._create_server()
+        proxy_client = ssh.Client(proxy['fip']['floating_ip_address'],
+                                  CONF.validation.image_ssh_user,
+                                  pkey=self.keypair['private_key'])
+        src_server = self._create_server(create_floating_ip=False)
+        src_server_ip = src_server['port']['fixed_ips'][0]['ip_address']
+        ssh_client = ssh.Client(src_server_ip,
+                                CONF.validation.image_ssh_user,
+                                pkey=self.keypair['private_key'],
+                                proxy_client=proxy_client)
+        self.check_remote_connectivity(ssh_client,
+                                       gateway_external_ip)