diff --git a/xCAT/postscripts/xcatlib.sh b/xCAT/postscripts/xcatlib.sh
index e5b5da8fd..17a5adf6f 100644
--- a/xCAT/postscripts/xcatlib.sh
+++ b/xCAT/postscripts/xcatlib.sh
@@ -1,17 +1,73 @@
 function hashencode(){
-        local map="$1"
-         echo `echo $map | sed 's/\./xDOTx/g' | sed 's/:/xCOLONx/g' | sed 's/,/:xCOMMAx/g'`
+        local str_map="$1"
+         echo `echo $str_map | sed 's/\./xDOTx/g' | sed 's/:/xCOLONx/g' | sed 's/,/:xCOMMAx/g'`
 }
 
 function hashset(){
-    local hashname="hash${1}${2}"
-    local value=$3
-    hashname=$(hashencode $hashname)
-    eval "${hashname}='${value}'"
+    local str_hashname="hash${1}${2}"
+    local str_value=$3
+    str_hashname=$(hashencode $str_hashname)
+    eval "${str_hashname}='${str_value}'"
 }
 
 function hashget(){
-    local hashname="hash${1}${2}"
-    hashname=$(hashencode $hashname)
-    eval echo "\$${hashname}"
+    local str_hashname="hash${1}${2}"
+    str_hashname=$(hashencode $str_hashname)
+    eval echo "\$${str_hashname}"
 }
+
+function debianpreconf(){
+    #create the config sub dir
+    if [ ! -d "/etc/network/interfaces.d" ];then
+        mkdir -p "/etc/network/interfaces.d"
+    fi
+    #search xcat flag
+    `grep "#XCAT_CONFIG" /etc/network/interfaces`
+    if [ $? -eq 0 ];then
+        return
+    fi
+
+    #back up the old interface configure
+    if [ ! -e "/etc/network/interfaces.bak" ];then
+        mv /etc/network/interfaces /etc/network/interfaces.bak
+    fi
+
+    #create the new config file
+    echo "#XCAT_CONFIG" > /etc/network/interfaces
+    echo "source /etc/network/interfaces.d/*" >> /etc/network/interfaces
+
+    local str_conf_file=''
+
+    #read the backfile
+    cat /etc/network/interfaces.bak | while read str_line
+    do
+        if [ ! "$str_line" ];then
+            continue
+        fi
+        local str_first_char=${str_line:0:1}
+        if [ $str_first_char = '#' ];then
+            continue
+        fi
+
+        local str_conf_type=`echo $str_line | cut -d" " -f1`
+        if [ $str_conf_type = 'auto' -o $str_conf_type = 'allow-hotplug' ];then
+            str_line=${str_line#$str_conf_type}
+            for str_nic_name in $str_line; do
+                echo "$str_conf_type $str_nic_name" > "/etc/network/interfaces.d/$str_nic_name"
+            done
+        elif [ $str_conf_type = 'iface' -o $str_conf_type = 'mapping' ];then
+            #find out the nic name, should think about the eth0:1
+            str_nic_name=`echo $str_line | cut -d" " -f 2 | cut -d":" -f 1`
+            str_conf_file="/etc/network/interfaces.d/$str_nic_name"
+            if [ ! -e $str_conf_file ];then
+                echo "auto $str_nic_name" > $str_conf_file
+            fi
+
+            #write lines into the conffile
+            echo $str_line >> $str_conf_file
+        else
+            echo $str_line >> $str_conf_file
+        fi
+    done
+}
+