diff --git a/etc/neutron.conf b/etc/neutron.conf
index 5c31cb2f318..83a6dbe23de 100644
--- a/etc/neutron.conf
+++ b/etc/neutron.conf
@@ -211,8 +211,9 @@ notification_driver = neutron.openstack.common.notifier.rpc_notifier
 # max_fixed_ips_per_port = 5
 
 # =========== items for agent management extension =============
-# Seconds to regard the agent as down.
-# agent_down_time = 5
+# Seconds to regard the agent as down; should be at least twice
+# report_interval, to be sure the agent is down for good
+# agent_down_time = 9
 # ===========  end of items for agent management extension =====
 
 # =========== items for agent scheduler extension =============
@@ -301,8 +302,8 @@ notification_driver = neutron.openstack.common.notifier.rpc_notifier
 # root_helper = sudo
 
 # =========== items for agent management extension =============
-# seconds between nodes reporting state to server, should be less than
-# agent_down_time
+# seconds between nodes reporting state to server; should be less than
+# agent_down_time, best if it is half or less than agent_down_time
 # report_interval = 4
 
 # ===========  end of items for agent management extension =====
diff --git a/neutron/agent/common/config.py b/neutron/agent/common/config.py
index e00d43cc972..9d5f5b1c48e 100644
--- a/neutron/agent/common/config.py
+++ b/neutron/agent/common/config.py
@@ -33,7 +33,9 @@ ROOT_HELPER_OPTS = [
 
 AGENT_STATE_OPTS = [
     cfg.FloatOpt('report_interval', default=4,
-                 help=_('Seconds between nodes reporting state to server')),
+                 help=_('Seconds between nodes reporting state to server; '
+                        'should be less than agent_down_time, best if it '
+                        'is half or less than agent_down_time.')),
 ]
 
 
diff --git a/neutron/db/agents_db.py b/neutron/db/agents_db.py
index d04f7faf56b..e095a4c2a74 100644
--- a/neutron/db/agents_db.py
+++ b/neutron/db/agents_db.py
@@ -31,8 +31,10 @@ from neutron.openstack.common import timeutils
 
 LOG = logging.getLogger(__name__)
 cfg.CONF.register_opt(
-    cfg.IntOpt('agent_down_time', default=5,
-               help=_("Seconds to regard the agent is down.")))
+    cfg.IntOpt('agent_down_time', default=9,
+               help=_("Seconds to regard the agent is down; should be at "
+                      "least twice report_interval, to be sure the "
+                      "agent is down for good.")))
 
 
 class Agent(model_base.BASEV2, models_v2.HasId):