diff --git a/gestion/wifi-update.py b/gestion/wifi-update.py
index 3997c7c2..55032904 100755
--- a/gestion/wifi-update.py
+++ b/gestion/wifi-update.py
@@ -37,13 +37,14 @@
 
 # TODO: meilleure gestion des erreurs
 
+import commands,re
+
 # On utilise twisted
 # http://twistedmatrix.com/documents/current/howto/tutorial/intro
 from twisted.internet import protocol, reactor, defer, utils
 from twisted.internet.ssl import ContextFactory
 from twisted.protocols import basic
 from twisted.application import internet, service
-from twisted.names import client
 from twisted.python import log
 
 import sys, resource
@@ -143,10 +144,7 @@ class UpdateFactory(protocol.ServerFactory):
         def reset_host(self, host):
             # ETAPE 1
             # On commence par résoudre "host".
-            d = client.lookupPointer("%s.in-addr.arpa" % '.'.join(host.split('.')[::-1]))
-            d.addCallback(lambda (ans, auth, add), _ : reset_del(self, ans[0].payload.name),
-                          lambda _: reset_del(self, "unknown"))
-            return d
+            return defer.succeed(reset_del(self, RE.get_reverse(host)))
 
         def reset_del(self, host):
             # ETAPE 2
@@ -200,11 +198,7 @@ class UpdateFactory(protocol.ServerFactory):
         def getSAD_host(self, getre, delre, host):
             # ETAPE 1
             # On commence par résoudre "host".
-            d = client.lookupPointer("%s.in-addr.arpa" % '.'.join(host.split('.')[::-1]))
-            d.addCallback(lambda (ans, auth, add), _ : getSAD_lock(self, getre, delre,
-                                                                  ans[0].payload.name),
-                          lambda _: getSAD_lock(self, getre, delre, "unknown"))
-            return d
+            return getSAD_lock(self, getre, delre, RE.get_reverse(host))
 
         def getSAD_lock(self, getre, delre, host):
             # ETAPE 2
@@ -263,7 +257,7 @@ class UpdateFactory(protocol.ServerFactory):
 
                 remove_lock('gen_confs.wifi')
                 if len(result) > 5:
-                    print "We send the following script :"
+                    print "We send the following script to %s :" % host
                     print result
                 return result
             
@@ -274,6 +268,40 @@ class UpdateFactory(protocol.ServerFactory):
 
 # Corps du programme
 
+class ReverseEngine:
+
+    import time
+
+    def __init__(self):
+        self.iphost = None
+        self.lastupdate = 0
+
+    def get_reverse(self,ip):
+    
+        def build_reverse(server="138.231.136.6"):
+            """Construit une correspondance IP -> nom"""
+            pattern = re.compile("^(.*).in-addr.arpa domain name pointer (.*)\.")
+            result = {}
+            for line in commands.getoutput("host -l 148.231.138.in-addr.arpa %s" % server).split("\n"):
+                mo =  pattern.match(line.strip())
+                if mo:
+                    ip = ".".join(mo.group(1).split(".")[::-1])
+                    result[ip] = mo.group(2)
+            return result
+    
+        current = time.time()
+        if not self.iphost or current - self.lastupdate > 60:
+            self.iphost = build_reverse()
+            self.lastupdate = current
+
+        if ip not in self.iphost:
+            return "unknown"
+        else:
+            return self.iphost[ip]
+
+RE = ReverseEngine()
+
+
 # On augmente la limite soft (qui semble arreter python).
 # Sous Open, on peut utiliser fstat pour voir les fichiers ouverts.
 # On a besoin de 3 * nombre de bornes pour le nombre de descripteurs