diff --git a/frankenrouter.py b/frankenrouter.py
index f151546..c7434e0 100644
--- a/frankenrouter.py
+++ b/frankenrouter.py
@@ -307,8 +307,8 @@ if __name__ == "__main__":
 python3 frankenrouter.py init --- setup the default firewall
 python3 frankenrouter.py allipsetup --- read the contents of /root/pubip.cache and setup all assigments. for startup.
 
-python3 frankenrouter.py ipadd IP MASK VLAN --- add IP to VLAN
-    example: ipadd 87.120.110.120 24 142
+python3 frankenrouter.py ipadd IP VLAN --- add IP to VLAN
+    example: ipadd 87.120.110.120 142
 
 python3 frankenrouter,py ipdel IP VLAN --- del IP from VLAN
     example: ipdel 87.120.110.120 142
@@ -328,7 +328,7 @@ python3 frankenrouter,py ipdel IP VLAN --- del IP from VLAN
             allipsetup('/root/pubip.cache', ip_mask)
 
         if sys.argv[1] == 'ipadd':
-            bashexec('ipadd-{}-{}-{}'.format(sys.argv[2], ip_mask, sys.argv[3]), assignip(sys.argv[2], ip_mask, sys.argv[3]))
+            bashexec('ipadd-{}-{}'.format(sys.argv[2], sys.argv[3]), assignip(sys.argv[2], ip_mask, sys.argv[3]))
 
         if sys.argv[1] == 'ipdel':
             bashexec('ipdel-{}-{}'.format(sys.argv[2], sys.argv[3]), removeip(sys.argv[2], sys.argv[3]))
diff --git a/updateipcache.py b/updateipcache.py
index 1a2bf0f..3742efb 100644
--- a/updateipcache.py
+++ b/updateipcache.py
@@ -4,12 +4,28 @@ import requests
 import json
 import sys
 import re
+import subprocess
 
-conffile = open('/root/frankenrouter/config.sh', 'r')
-for line in conffile:
-    if re.search('LABEL', line):
-        slave_name = line.split('=', 1)[1].rstrip().replace('"', '')
-conffile.close()
+class DictDiffer(object):
+    """
+    Calculate the difference between two dictionaries as:
+    (1) items added
+    (2) items removed
+    (3) keys same in both but changed values
+    (4) keys same in both and unchanged values
+    """
+    def __init__(self, current_dict, past_dict):
+        self.current_dict, self.past_dict = current_dict, past_dict
+        self.set_current, self.set_past = set(current_dict.keys()), set(past_dict.keys())
+        self.intersect = self.set_current.intersection(self.set_past)
+    def added(self):
+        return self.set_current - self.intersect 
+    def removed(self):
+        return self.set_past - self.intersect 
+    def changed(self):
+        return set(o for o in self.intersect if self.past_dict[o] != self.current_dict[o])
+    def unchanged(self):
+        return set(o for o in self.intersect if self.past_dict[o] == self.current_dict[o])
 
 conffile = open('/root/frankenrouter/config.sh', 'r')
 for line in conffile:
@@ -19,6 +35,12 @@ conffile.close()
 
 api_url = 'https://' + str(api_host) + '/vmanager/slavetables'
 
+conffile = open('/root/frankenrouter/config.sh', 'r')
+for line in conffile:
+    if re.search('LABEL', line):
+        slave_name = line.split('=', 1)[1].rstrip().replace('"', '')
+conffile.close()
+
 ###
 
 try:
@@ -26,15 +48,47 @@ try:
     apireq = requests.post(api_url, headers={'Content-Type': 'application/json'}, data=json.dumps(data), timeout=30)
     result = apireq.json()
 except:
+    print('can not connect')
     sys.exit()
 
 if result['status'] == 'ok':
     del result['status']
-    wr = open('/root/pubip.cache', 'w')
-    #TODO: Sort cache and compare.
-    wr.write(json.dumps(result))
-    wr.close()
-    print('public ip cache updated')
+    new_list = result
+
+    # read cache to load the old values
+    r_ca = open('/root/pubip.cache', 'r')
+    current_list = json.loads(r_ca.read())
+    r_ca.close()
+
+    #compare the current value with the cache
+    newdataflag = False
+    difference = DictDiffer(new_list, current_list)
+    if len(difference.added()) is not 0:
+        for ipkey in difference.added():
+            ip = ipkey
+            vlan = new_list[ipkey]
+            print('added {} to {}'.format(ip, vlan))
+            newdataflag = True
+            subprocess.call('python3 /root/frankenrouter/frankenrouter.py ipadd {} {}'.format(ip, vlan), shell=True)
+    if len(difference.removed()) is not 0:
+        for ipkey in difference.removed():
+            ip = ipkey
+            vlan = current_list[ipkey]
+            print('removed {} from {}'.format(ip, vlan))
+            newdataflag = True
+            subprocess.call('python3 /root/frankenrouter/frankenrouter.py ipdel {} {}'.format(ip, vlan), shell=True)
+
+    if newdataflag:
+        # move the old cache and write the new data
+        subprocess.call('mv /root/pubip.cache /root/pubip.cache.old', shell=True)
+        w_ca = open('/root/pubip.cache', 'w')
+        w_ca.write(json.dumps(new_list))
+        w_ca.close()
+        print('public ip cache updated with the new data')
+    else:
+        pass
 
 else:
-    print('no data')
+    print('no data error')
+
+