--- a/src/plugins/plugin_misc_ip.py	Mon Nov 02 22:02:41 2015 +0100
+++ b/src/plugins/plugin_misc_ip.py	Mon Nov 02 22:02:41 2015 +0100
@@ -27,6 +27,7 @@
 from twisted.internet import reactor
 from twisted.internet import protocol
 from twisted.internet import endpoints
+from twisted.internet import error as internet_error
 import urlparse
 try:
     import netifaces
@@ -92,11 +93,13 @@
 
         # XXX: cache is kept until SàT is restarted
         #      if IP may have changed, use self.refreshIP
-        self._ip_cache = None
+        self._external_ip_cache = None
+        self._local_ip_cache = None
 
     def refreshIP(self):
         # FIXME: use a trigger instead ?
-        self._ip_cache = None
+        self._external_ip_cache = None
+        self._local_ip_cache = None
 
     def _externalAllowed(self, profile):
         """Return value of parameter with autorisation of user to do external requests
@@ -112,7 +115,7 @@
             def setParam(allowed):
                 # FIXME: we need to use boolConst as setParam only manage str/unicode
                 #        need to be fixed when params will be refactored
-                self.host.memory.setParam(GET_IP_NAME, C.boolConst(allow_get_ip), GET_IP_CATEGORY)
+                self.host.memory.setParam(GET_IP_NAME, C.boolConst(allowed), GET_IP_CATEGORY)
                 return allowed
             d = xml_tools.deferConfirm(self.host, _(GET_IP_CONFIRM), _(GET_IP_CONFIRM_TITLE), profile=profile)
             d.addCallback(setParam)
@@ -146,7 +149,7 @@
         """Get local IP by doing a connection on an external url
 
         @param ext_utl(str): url to connect to
-        @return (defer.Deferred): return local IP
+        @return (D(str)): return local IP
         """
         url = urlparse.urlparse(ext_url)
         port = url.port
@@ -182,6 +185,8 @@
             if there are several addresses, the one used with the server is put first
         """
         # TODO: manage permission requesting (e.g. for UMTS link)
+        if self._local_ip_cache is not None:
+            defer.returnValue(self._local_ip_cache)
         client = self.host.getClient(profile)
         addresses = []
 
@@ -221,7 +226,11 @@
             if not allow_get_ip:
                 defer.returnValue(addresses)
 
-        ip_tuple = yield self._getIPFromExternal(GET_IP_PAGE)
+        try:
+            ip_tuple = yield self._getIPFromExternal(GET_IP_PAGE)
+        except Exception as internet_error.DNSLookupError:
+            log.warning(u"Can't access Domain Name System")
+            defer.returnValue(addresses)
         self._insertFirst(addresses, ip_tuple.local)
         defer.returnValue(addresses)
 
@@ -233,16 +242,23 @@
         @param profile: %(doc_profile)s
         @return (deferred): external IP address or None if it can't be discovered
         """
-        if self._ip_cache is not None:
-            defer.returnValue(self._ip_cache)
+        if self._external_ip_cache is not None:
+            defer.returnValue(self._external_ip_cache)
 
         # we first try with NAT-Port
         if self._nat is not None:
             nat_ip = yield self._nat.getIP()
             if nat_ip is not None:
+                self._external_ip_cache = nat_ip
                 defer.returnValue(nat_ip)
 
         # then by requesting external website
         allow_get_ip = yield self._externalAllowed(profile)
-        ip = webclient.getPage(GET_IP_PAGE) if allow_get_ip else None
+        try:
+            ip = (yield webclient.getPage(GET_IP_PAGE)) if allow_get_ip else None
+        except internet_error.DNSLookupError:
+            log.warning(u"Can't access Domain Name System")
+            ip = None
+        else:
+            self._external_ip_cache = ip
         defer.returnValue(ip)