diff --git a/neutron_tempest_plugin/scenario/test_trunk.py b/neutron_tempest_plugin/scenario/test_trunk.py
index b5e8cda..2ff7e5d 100644
--- a/neutron_tempest_plugin/scenario/test_trunk.py
+++ b/neutron_tempest_plugin/scenario/test_trunk.py
@@ -34,7 +34,8 @@
     'sudo su -c '
     '"ip l a link $IFACE name $IFACE.%(tag)d type vlan id %(tag)d &&'
     'ip l s up dev $IFACE.%(tag)d && '
-    'dhclient $IFACE.%(tag)d"')
+    '{ ps -ef | grep -q "dhclient .*$IFACE.%(tag)d" || '
+    'dhclient $IFACE.%(tag)d"; }')
 
 
 class TrunkTest(base.BaseTempestTestCase):