diff --git a/neutron/agent/l3/ha.py b/neutron/agent/l3/ha.py
index 9a55d25c256..aa77b729066 100644
--- a/neutron/agent/l3/ha.py
+++ b/neutron/agent/l3/ha.py
@@ -122,10 +122,23 @@ class AgentMixin(object):
                          'possibly deleted concurrently.'), router_id)
             return
 
+        self._configure_ipv6_ra_on_ext_gw_port_if_necessary(ri, state)
         self._update_metadata_proxy(ri, router_id, state)
         self._update_radvd_daemon(ri, state)
         self.state_change_notifier.queue_event((router_id, state))
 
+    def _configure_ipv6_ra_on_ext_gw_port_if_necessary(self, ri, state):
+        # If ipv6 is enabled on the platform, ipv6_gateway config flag is
+        # not set and external_network associated to the router does not
+        # include any IPv6 subnet, enable the gateway interface to accept
+        # Router Advts from upstream router for default route.
+        ex_gw_port_id = ri.ex_gw_port and ri.ex_gw_port['id']
+        if state == 'master' and ex_gw_port_id and ri.use_ipv6:
+            gateway_ips = ri._get_external_gw_ips(ri.ex_gw_port)
+            if not ri.is_v6_gateway_set(gateway_ips):
+                interface_name = ri.get_external_device_name(ex_gw_port_id)
+                ri.driver.configure_ipv6_ra(ri.ns_name, interface_name)
+
     def _update_metadata_proxy(self, ri, router_id, state):
         if state == 'master':
             LOG.debug('Spawning metadata proxy for router %s', router_id)
diff --git a/neutron/agent/l3/ha_router.py b/neutron/agent/l3/ha_router.py
index fd15e19b37e..92493578d84 100644
--- a/neutron/agent/l3/ha_router.py
+++ b/neutron/agent/l3/ha_router.py
@@ -192,7 +192,7 @@ class HaRouter(router.RouterInfo):
         self.routes = new_routes
 
     def _add_default_gw_virtual_route(self, ex_gw_port, interface_name):
-        gateway_ips, enable_ra_on_gw = self._get_external_gw_ips(ex_gw_port)
+        gateway_ips = self._get_external_gw_ips(ex_gw_port)
         for gw_ip in gateway_ips:
                 # TODO(Carl) This is repeated everywhere.  A method would
                 # be nice.
@@ -207,9 +207,6 @@ class HaRouter(router.RouterInfo):
                     keepalived.KeepalivedVirtualRoute(
                         default_gw, gw_ip, interface_name))
 
-        if enable_ra_on_gw:
-            self.driver.configure_ipv6_ra(self.ns_name, interface_name)
-
     def _should_delete_ipv6_lladdr(self, ipv6_lladdr):
         """Only the master should have any IP addresses configured.
         Let keepalived manage IPv6 link local addresses, the same way we let
diff --git a/neutron/agent/l3/router_info.py b/neutron/agent/l3/router_info.py
index 66d45dd4272..8f2b930bad3 100644
--- a/neutron/agent/l3/router_info.py
+++ b/neutron/agent/l3/router_info.py
@@ -434,7 +434,6 @@ class RouterInfo(object):
 
     def _get_external_gw_ips(self, ex_gw_port):
         gateway_ips = []
-        enable_ra_on_gw = False
         if 'subnets' in ex_gw_port:
             gateway_ips = [subnet['gateway_ip']
                            for subnet in ex_gw_port['subnets']
@@ -444,11 +443,7 @@ class RouterInfo(object):
             if self.agent_conf.ipv6_gateway:
                 # ipv6_gateway configured, use address for default route.
                 gateway_ips.append(self.agent_conf.ipv6_gateway)
-            else:
-                # ipv6_gateway is also not configured.
-                # Use RA for default route.
-                enable_ra_on_gw = True
-        return gateway_ips, enable_ra_on_gw
+        return gateway_ips
 
     def _external_gateway_added(self, ex_gw_port, interface_name,
                                 ns_name, preserve_ips):
@@ -458,7 +453,11 @@ class RouterInfo(object):
         # will be added to the interface.
         ip_cidrs = common_utils.fixed_ip_cidrs(ex_gw_port['fixed_ips'])
 
-        gateway_ips, enable_ra_on_gw = self._get_external_gw_ips(ex_gw_port)
+        gateway_ips = self._get_external_gw_ips(ex_gw_port)
+        enable_ra_on_gw = False
+        if self.use_ipv6 and not self.is_v6_gateway_set(gateway_ips):
+            # There is no IPv6 gw_ip, use RouterAdvt for default route.
+            enable_ra_on_gw = True
         self.driver.init_l3(interface_name,
                             ip_cidrs,
                             namespace=ns_name,