diff --git a/xCAT-nbroot2/restart b/xCAT-nbroot2/restart
index 059ade921..f0736629d 100755
--- a/xCAT-nbroot2/restart
+++ b/xCAT-nbroot2/restart
@@ -7,7 +7,7 @@ if [ ! -z "$FORCENICS" ]; then
     for pidfile in /var/run/dhclient.*.pid; do
 	NIC=`echo $pidfile|awk -F. '{print $2}'`
 	if [ ! -z "$NIC" -a "$NIC" != "$FORCENICS" ]; then
-		dhclient -r -cf /etc/dhclient.conf -pf $pidfile $NIC
+		dhclient -r -1 -cf /etc/dhclient.conf -pf $pidfile $NIC
 		rm $pidfile
 		ip link set $NIC down
 	fi
@@ -15,7 +15,7 @@ if [ ! -z "$FORCENICS" ]; then
     for pidfile in /var/run/dhclient6.*.pid; do
 	NIC=`echo $pidfile|awk -F. '{print $2}'`
 	if [ ! -z "$NIC" -a "$NIC" != "$FORCENICS" ]; then
-		dhclient -6 -r -pf $pidfile -lf /var/lib/dhclient/dhclient6.leases $NIC
+		dhclient -6 -r -1 -pf $pidfile -lf /var/lib/dhclient/dhclient6.leases $NIC
 		rm $pidfile
 		ip link set $NIC down
 	fi
@@ -25,12 +25,12 @@ WAITING=1
 while [ $WAITING -gt 0 ]; do
     for pidfile in /var/run/dhclient.*.pid; do
 	NIC=`echo $pidfile|awk -F. '{print $2}'`
-	dhclient -r -cf /etc/dhclient.conf -pf $pidfile $NIC
+	dhclient -r -1 -cf /etc/dhclient.conf -pf $pidfile $NIC
 	dhclient -cf /etc/dhclient.conf -nw -pf $pidfile $NIC
     done
     for pidfile in /var/run/dhclient6.*.pid; do
 	NIC=`echo $pidfile|awk -F. '{print $2}'`
-	dhclient -6 -r -pf $pidfile -lf /var/lib/dhclient/dhclient6.leases $NIC
+	dhclient -6 -r -1 -pf $pidfile -lf /var/lib/dhclient/dhclient6.leases $NIC
 	dhclient -6 -pf $pidfile -nw -lf /var/lib/dhclient/dhclient6.leases $NIC
     done