diff --git a/tempest/api/network/base.py b/tempest/api/network/base.py
index 159c4f5..ed915c1 100644
--- a/tempest/api/network/base.py
+++ b/tempest/api/network/base.py
@@ -215,3 +215,19 @@
         vpnservice = body['vpnservice']
         cls.vpnservices.append(vpnservice)
         return vpnservice
+
+
+class BaseAdminNetworkTest(BaseNetworkTest):
+
+    @classmethod
+    def setUpClass(cls):
+        super(BaseAdminNetworkTest, cls).setUpClass()
+        admin_username = cls.config.compute_admin.username
+        admin_password = cls.config.compute_admin.password
+        admin_tenant = cls.config.compute_admin.tenant_name
+        if not (admin_username and admin_password and admin_tenant):
+            msg = ("Missing Administrative Network API credentials "
+                   "in configuration.")
+            raise cls.skipException(msg)
+        cls.admin_manager = clients.AdminManager(interface=cls._interface)
+        cls.admin_client = cls.admin_manager.network_client
diff --git a/tempest/api/network/test_routers.py b/tempest/api/network/test_routers.py
index 2cfbf61..512d065 100644
--- a/tempest/api/network/test_routers.py
+++ b/tempest/api/network/test_routers.py
@@ -20,7 +20,10 @@
 from tempest.test import attr
 
 
-class RoutersTest(base.BaseNetworkTest):
+class RoutersTest(base.BaseAdminNetworkTest):
+    # NOTE(salv-orlando): This class inherits from BaseAdminNetworkTest
+    # as some router operations, such as enabling or disabling SNAT
+    # require admin credentials by default
     _interface = 'json'
 
     @classmethod
@@ -130,3 +133,99 @@
             interface['port_id'])
         self.assertEqual(show_port_body['port']['device_id'],
                          router['id'])
+
+    def _verify_router_gateway(self, router_id, exp_ext_gw_info=None):
+        resp, show_body = self.client.show_router(router_id)
+        self.assertEqual('200', resp['status'])
+        actual_ext_gw_info = show_body['router']['external_gateway_info']
+        if exp_ext_gw_info is None:
+            self.assertIsNone(actual_ext_gw_info)
+            return
+        # Verify only keys passed in exp_ext_gw_info
+        for k, v in exp_ext_gw_info.iteritems():
+            self.assertEqual(v, actual_ext_gw_info[k])
+
+    def _verify_gateway_port(self, router_id):
+        resp, list_body = self.admin_client.list_ports(
+            network_id=self.network_cfg.public_network_id,
+            device_id=router_id)
+        self.assertEqual(len(list_body['ports']), 1)
+        gw_port = list_body['ports'][0]
+        fixed_ips = gw_port['fixed_ips']
+        self.assertEqual(len(fixed_ips), 1)
+        resp, public_net_body = self.admin_client.show_network(
+            self.network_cfg.public_network_id)
+        public_subnet_id = public_net_body['network']['subnets'][0]
+        self.assertEqual(fixed_ips[0]['subnet_id'], public_subnet_id)
+
+    @attr(type='smoke')
+    def test_update_router_set_gateway(self):
+        router = self.create_router(rand_name('router-'))
+        self.client.update_router(
+            router['id'],
+            external_gateway_info={
+                'network_id': self.network_cfg.public_network_id})
+        # Verify operation - router
+        resp, show_body = self.client.show_router(router['id'])
+        self.assertEqual('200', resp['status'])
+        self._verify_router_gateway(
+            router['id'],
+            {'network_id': self.network_cfg.public_network_id})
+        self._verify_gateway_port(router['id'])
+
+    @attr(type='smoke')
+    def test_update_router_set_gateway_with_snat_explicit(self):
+        router = self.create_router(rand_name('router-'))
+        self.admin_client.update_router_with_snat_gw_info(
+            router['id'],
+            external_gateway_info={
+                'network_id': self.network_cfg.public_network_id,
+                'enable_snat': True})
+        self._verify_router_gateway(
+            router['id'],
+            {'network_id': self.network_cfg.public_network_id,
+             'enable_snat': True})
+        self._verify_gateway_port(router['id'])
+
+    @attr(type='smoke')
+    def test_update_router_set_gateway_without_snat(self):
+        router = self.create_router(rand_name('router-'))
+        self.admin_client.update_router_with_snat_gw_info(
+            router['id'],
+            external_gateway_info={
+                'network_id': self.network_cfg.public_network_id,
+                'enable_snat': False})
+        self._verify_router_gateway(
+            router['id'],
+            {'network_id': self.network_cfg.public_network_id,
+             'enable_snat': False})
+        self._verify_gateway_port(router['id'])
+
+    @attr(type='smoke')
+    def test_update_router_unset_gateway(self):
+        router = self.create_router(
+            rand_name('router-'),
+            external_network_id=self.network_cfg.public_network_id)
+        self.client.update_router(router['id'], external_gateway_info={})
+        self._verify_router_gateway(router['id'])
+        # No gateway port expected
+        resp, list_body = self.admin_client.list_ports(
+            network_id=self.network_cfg.public_network_id,
+            device_id=router['id'])
+        self.assertFalse(list_body['ports'])
+
+    @attr(type='smoke')
+    def test_update_router_reset_gateway_without_snat(self):
+        router = self.create_router(
+            rand_name('router-'),
+            external_network_id=self.network_cfg.public_network_id)
+        self.admin_client.update_router_with_snat_gw_info(
+            router['id'],
+            external_gateway_info={
+                'network_id': self.network_cfg.public_network_id,
+                'enable_snat': False})
+        self._verify_router_gateway(
+            router['id'],
+            {'network_id': self.network_cfg.public_network_id,
+             'enable_snat': False})
+        self._verify_gateway_port(router['id'])
diff --git a/tempest/services/network/json/network_client.py b/tempest/services/network/json/network_client.py
index 92c1faf..e7cd33f 100644
--- a/tempest/services/network/json/network_client.py
+++ b/tempest/services/network/json/network_client.py
@@ -123,8 +123,12 @@
         resp, body = self.delete(uri, self.headers)
         return resp, body
 
-    def list_ports(self):
+    def list_ports(self, **filters):
         uri = '%s/ports' % (self.uri_prefix)
+        filter_items = ["%s=%s" % (k, v) for (k, v) in filters.iteritems()]
+        querystring = "&".join(filter_items)
+        if querystring:
+            uri = "%s?%s" % (uri, querystring)
         resp, body = self.get(uri, self.headers)
         body = json.loads(body)
         return resp, body
@@ -223,7 +227,7 @@
         body = json.loads(body)
         return resp, body
 
-    def update_router(self, router_id, **kwargs):
+    def _update_router(self, router_id, set_enable_snat, **kwargs):
         uri = '%s/routers/%s' % (self.uri_prefix, router_id)
         resp, body = self.get(uri, self.headers)
         body = json.loads(body)
@@ -231,15 +235,34 @@
         update_body['name'] = kwargs.get('name', body['router']['name'])
         update_body['admin_state_up'] = kwargs.get(
             'admin_state_up', body['router']['admin_state_up'])
-        # Must uncomment/modify these lines once LP question#233187 is solved
-        # update_body['external_gateway_info'] = kwargs.get(
-        # 'external_gateway_info', body['router']['external_gateway_info'])
+        cur_gw_info = body['router']['external_gateway_info']
+        if cur_gw_info and not set_enable_snat:
+            cur_gw_info.pop('enable_snat', None)
+        update_body['external_gateway_info'] = kwargs.get(
+            'external_gateway_info', body['router']['external_gateway_info'])
         update_body = dict(router=update_body)
         update_body = json.dumps(update_body)
         resp, body = self.put(uri, update_body, self.headers)
         body = json.loads(body)
         return resp, body
 
+    def update_router(self, router_id, **kwargs):
+        """Update a router leaving enable_snat to its default value."""
+        # If external_gateway_info contains enable_snat the request will fail
+        # with 404 unless executed with admin client, and therefore we instruct
+        # _update_router to not set this attribute
+        # NOTE(salv-orlando): The above applies as long as Neutron's default
+        # policy is to restrict enable_snat usage to admins only.
+        return self._update_router(router_id, set_enable_snat=False, **kwargs)
+
+    def update_router_with_snat_gw_info(self, router_id, **kwargs):
+        """Update a router passing also the enable_snat attribute.
+
+        This method must be execute with admin credentials, otherwise the API
+        call will return a 404 error.
+        """
+        return self._update_router(router_id, set_enable_snat=True, **kwargs)
+
     def add_router_interface_with_subnet_id(self, router_id, subnet_id):
         uri = '%s/routers/%s/add_router_interface' % (self.uri_prefix,
               router_id)