diff --git a/xCAT-test/autotest/testcase/confignetwork/cases0 b/xCAT-test/autotest/testcase/confignetwork/cases0
index b1b4b6ed4..911f01641 100644
--- a/xCAT-test/autotest/testcase/confignetwork/cases0
+++ b/xCAT-test/autotest/testcase/confignetwork/cases0
@@ -607,7 +607,7 @@ cmd:xdsh $$CN "rm -rf /tmp/backupnet/"
 cmd:xdsh $$CN "mkdir -p /tmp/backupnet/"
 check:rc==0
 cmd:if grep SUSE /etc/*release;then xdsh $$CN "cp -f /etc/sysconfig/network/ifcfg-* /tmp/backupnet/"; elif grep -E "Red Hat|CentOS" /etc/*release;then xdsh $$CN "cp -rf /etc/sysconfig/network-scripts /tmp/backupnet/"; elif grep Ubuntu /etc/*release;then xdsh $$CN "cp -f /etc/network/interfaces.d/* /tmp/backupnet/";else echo "Sorry,this is not supported os"; fi
-cmd:if grep -E "Red Hat|CentOS" /etc/*release | grep "release 7";then xdsh $$CN "yum -y install bridge-utils";fi
+cmd:if grep -E "Red Hat|CentOS" /etc/*release;then xdsh $$CN "if yum -q list bridge-utils ; then yum -y install bridge-utils; fi";fi
 cmd:cnip=__GETNODEATTR($$CN,ip)__;echo $cnip;var3=100.;var4=`echo $cnip |awk -F. '{print $2}'`;var5=.0.0;secondnet=$var3$var4$var5;mkdef -t network -o confignetworks_test1 net=$secondnet mask=255.255.0.0 mgtifname=$$SECONDNIC
 check:rc==0
 cmd:cnip=__GETNODEATTR($$CN,ip)__;echo $cnip;var1=100;var2=`echo $cnip |sed -r 's/[^\.]{1,3}(\..*)/\1/'`;second1ip=$var1$var2;chdef $$CN nicips.$$SECONDNIC=$second1ip nictypes.$$SECONDNIC=Ethernet nicnetworks.$$SECONDNIC=confignetworks_test1
@@ -663,7 +663,7 @@ cmd:xdsh $$CN "rm -rf /tmp/backupnet/"
 cmd:xdsh $$CN "mkdir -p /tmp/backupnet/"
 check:rc==0
 cmd:if grep SUSE /etc/*release;then xdsh $$CN "cp -f /etc/sysconfig/network/ifcfg-* /tmp/backupnet/"; elif grep -E "Red Hat|CentOS" /etc/*release;then xdsh $$CN "cp -f /etc/sysconfig/network-scripts/ifcfg-* /tmp/backupnet/"; elif grep Ubuntu /etc/*release;then xdsh $$CN "cp -f /etc/network/interfaces.d/* /tmp/backupnet/";else echo "Sorry,this is not supported os"; fi
-cmd:if grep -E "Red Hat|CentOS" /etc/*release | grep "release 7";then xdsh $$CN "yum -y install bridge-utils";fi
+cmd:if grep -E "Red Hat|CentOS" /etc/*release;then xdsh $$CN "if yum -q list bridge-utils ; then yum -y install bridge-utils; fi";fi
 cmd:cnip=__GETNODEATTR($$CN,ip)__;echo $cnip;var3=100.;var4=`echo $cnip |awk -F. '{print $2}'`;var5=.0.0;secondnet=$var3$var4$var5;mkdef -t network -o confignetworks_test1 net=$secondnet mask=255.255.0.0 mgtifname=$$SECONDNIC
 check:rc==0
 cmd:cnip=__GETNODEATTR($$CN,ip)__;echo $cnip;var1=100;var2=`echo $cnip |sed -r 's/[^\.]{1,3}(\..*)/\1/'`;second1ip=$var1$var2;chdef $$CN nicips.$$SECONDNIC=$second1ip nictypes.$$SECONDNIC=Ethernet nicnetworks.$$SECONDNIC=confignetworks_test1
@@ -712,7 +712,7 @@ cmd:xdsh $$CN "rm -rf /tmp/backupnet/"
 cmd:xdsh $$CN "mkdir -p /tmp/backupnet/"
 check:rc==0
 cmd:if grep SUSE /etc/*release;then xdsh $$CN "cp -f /etc/sysconfig/network/ifcfg-* /tmp/backupnet/"; elif grep -E "Red Hat|CentOS" /etc/*release;then xdsh $$CN "cp -rf /etc/sysconfig/network-scripts /tmp/backupnet/"; elif grep Ubuntu /etc/*release;then xdsh $$CN "cp -f /etc/network/interfaces.d/* /tmp/backupnet/;cp -f /etc/network/interfaces /tmp";else echo "Sorry,this is not supported os"; fi
-cmd:if grep -E "Red Hat|CentOS" /etc/*release | grep "release 7";then xdsh $$CN "yum -y install bridge-utils";fi
+cmd:if grep -E "Red Hat|CentOS" /etc/*release;then xdsh $$CN "if yum -q list bridge-utils ; then yum -y install bridge-utils; fi";fi
 cmd:cnip=__GETNODEATTR($$CN,ip)__;echo $cnip;var3=100.;var4=`echo $cnip |awk -F. '{print $2}'`;var5=.0.0;secondnet=$var3$var4$var5;mkdef -t network -o confignetworks_test1 net=$secondnet mask=255.255.0.0 mgtifname=$$SECONDNIC mtu=1500
 check:rc==0
 cmd:cnip=__GETNODEATTR($$CN,ip)__;echo $cnip;var1=100;var2=`echo $cnip |sed -r 's/[^\.]{1,3}(\..*)/\1/'`;second1ip=$var1$var2;chdef $$CN nicips.$$SECONDNIC=$second1ip nictypes.$$SECONDNIC=Ethernet nicnetworks.$$SECONDNIC=confignetworks_test1
@@ -780,7 +780,7 @@ cmd:xdsh $$CN "rm -rf /tmp/backupnet/"
 cmd:xdsh $$CN "mkdir -p /tmp/backupnet/"
 check:rc==0
 cmd:if grep SUSE /etc/*release;then xdsh $$CN "cp -f /etc/sysconfig/network/ifcfg-* /tmp/backupnet/"; elif grep -E "Red Hat|CentOS" /etc/*release;then xdsh $$CN "cp -rf /etc/sysconfig/network-scripts /tmp/backupnet/"; elif grep Ubuntu /etc/*release;then xdsh $$CN "cp -f /etc/network/interfaces.d/* /tmp/backupnet/";else echo "Sorry,this is not supported os"; fi
-cmd:if grep -E "Red Hat|CentOS" /etc/*release | grep "release 7";then xdsh $$CN "yum -y install bridge-utils";fi
+cmd:if grep -E "Red Hat|CentOS" /etc/*release;then xdsh $$CN "if yum -q list bridge-utils ; then yum -y install bridge-utils; fi";fi
 cmd:cnip=__GETNODEATTR($$CN,ip)__;echo $cnip;var3=100.;var4=`echo $cnip |awk -F. '{print $2}'`;var5=.0.0;secondnet=$var3$var4$var5;mkdef -t network -o confignetworks_test1 net=$secondnet mask=255.255.0.0 mgtifname=$$SECONDNIC
 check:rc==0
 cmd:cnip=__GETNODEATTR($$CN,ip)__;echo $cnip;var1=100;var2=`echo $cnip |sed -r 's/[^\.]{1,3}(\..*)/\1/'`;second1ip=$var1$var2;chdef $$CN nicips.$$SECONDNIC=$second1ip nictypes.$$SECONDNIC=Ethernet nicnetworks.$$SECONDNIC=confignetworks_test1
@@ -835,7 +835,7 @@ cmd:xdsh $$CN "rm -rf /tmp/backupnet/"
 cmd:xdsh $$CN "mkdir -p /tmp/backupnet/"
 check:rc==0
 cmd:if grep SUSE /etc/*release;then xdsh $$CN "cp -f /etc/sysconfig/network/ifcfg-* /tmp/backupnet/"; elif grep -E "Red Hat|CentOS" /etc/*release;then xdsh $$CN "cp -rf /etc/sysconfig/network-scripts /tmp/backupnet/"; elif grep Ubuntu /etc/*release;then xdsh $$CN "cp -f /etc/network/interfaces.d/* /tmp/backupnet/;cp -f /etc/network/interfaces /tmp";else echo "Sorry,this is not supported os"; fi
-cmd:if grep -E "Red Hat|CentOS" /etc/*release | grep "release 7";then xdsh $$CN "yum -y install bridge-utils";fi
+cmd:if grep -E "Red Hat|CentOS" /etc/*release;then xdsh $$CN "if yum -q list bridge-utils ; then yum -y install bridge-utils; fi";fi
 cmd:cnip=__GETNODEATTR($$CN,ip)__;echo $cnip;var3=100.;var4=`echo $cnip |awk -F. '{print $2}'`;var5=.0.0;secondnet=$var3$var4$var5;mkdef -t network -o confignetworks_test1 net=$secondnet mask=255.255.0.0 mgtifname=$$SECONDNIC
 check:rc==0
 cmd:cnip=__GETNODEATTR($$CN,ip)__;echo $cnip;var1=100;var2=`echo $cnip |sed -r 's/[^\.]{1,3}(\..*)/\1/'`;second1ip=$var1$var2;chdef $$CN nicips.$$SECONDNIC=$second1ip nictypes.$$SECONDNIC=Ethernet nicnetworks.$$SECONDNIC=confignetworks_test1
@@ -902,7 +902,7 @@ cmd:xdsh $$CN "rm -rf /tmp/backupnet/"
 cmd:xdsh $$CN "mkdir -p /tmp/backupnet/"
 check:rc==0
 cmd:if grep SUSE /etc/*release;then xdsh $$CN "cp -f /etc/sysconfig/network/ifcfg-* /tmp/backupnet/"; elif grep -E "Red Hat|CentOS" /etc/*release;then xdsh $$CN "cp -rf /etc/sysconfig/network-scripts /tmp/backupnet/"; elif grep Ubuntu /etc/*release;then xdsh $$CN "cp -f /etc/network/interfaces.d/* /tmp/backupnet/;cp -f /etc/network/interfaces /tmp";else echo "Sorry,this is not supported os"; fi
-cmd:if grep -E "Red Hat|CentOS" /etc/*release | grep "release 7";then xdsh $$CN "yum -y install bridge-utils";fi
+cmd:if grep -E "Red Hat|CentOS" /etc/*release;then xdsh $$CN "if yum -q list bridge-utils ; then yum -y install bridge-utils; fi";fi
 cmd:mkdef -t network -o 11_1_0_0-255_255_0_0 net=11.1.0.0 mask=255.255.0.0 mgtifname=$$SECONDNIC
 check:rc==0
 cmd:chdef $$CN nicips.$$SECONDNIC=11.1.0.100 nictypes.$$SECONDNIC=Ethernet nicnetworks.$$SECONDNIC=11_1_0_0-255_255_0_0
@@ -968,7 +968,7 @@ cmd:xdsh $$CN "rm -rf /tmp/backupnet/"
 cmd:xdsh $$CN "mkdir -p /tmp/backupnet/"
 check:rc==0
 cmd:if grep SUSE /etc/*release;then xdsh $$CN "cp -f /etc/sysconfig/network/ifcfg-* /tmp/backupnet/"; elif grep -E "Red Hat|CentOS" /etc/*release;then xdsh $$CN "cp -f /etc/sysconfig/network-scripts/ifcfg-* /tmp/backupnet/"; elif grep Ubuntu /etc/*release;then xdsh $$CN "cp -f /etc/network/interfaces.d/* /tmp/backupnet/";else echo "Sorry,this is not supported os"; fi
-cmd:if grep -E "Red Hat|CentOS" /etc/*release | grep "release 7";then xdsh $$CN "yum -y install bridge-utils";fi
+cmd:if grep -E "Red Hat|CentOS" /etc/*release;then xdsh $$CN "if yum -q list bridge-utils ; then yum -y install bridge-utils; fi";fi
 cmd:mkdef -t network -o 30_5_0_0-255_255_0_0 net=30.5.0.0 mask=255.255.0.0
 check:rc==0
 cmd:mkdef -t network -o 40_5_0_0-255_255_0_0 net=40.5.0.0 mask=255.255.0.0