diff --git a/test/test_option_validator.py b/test/test_option_validator.py
index 030a7c0..c26e5f6 100644
--- a/test/test_option_validator.py
+++ b/test/test_option_validator.py
@@ -3,6 +3,7 @@ from py.test import raises
 
 from tiramisu.config import Config
 from tiramisu.option import StrOption, OptionDescription
+from tiramisu.setting import groups
 
 
 def return_true(value, param=None):
@@ -88,3 +89,22 @@ def test_validator_warning():
     assert cfg.cfgimpl_get_values().get_last_warning() == 'invalid value val1 for option opt3: error'
     assert cfg.cfgimpl_get_values().has_warning() is False
     raises(ValueError, "cfg.opt2 = 1")
+
+
+def test_validator_warning_master_slave():
+    ip_admin_eth0 = StrOption('ip_admin_eth0', "ip reseau autorise", multi=True, validator=return_false, only_warning=True)
+    netmask_admin_eth0 = StrOption('netmask_admin_eth0', "masque du sous-reseau", multi=True, validator=return_if_val, only_warning=True)
+    interface1 = OptionDescription('ip_admin_eth0', '', [ip_admin_eth0, netmask_admin_eth0])
+    interface1.impl_set_group_type(groups.master)
+    assert interface1.impl_get_group_type() == groups.master
+    root = OptionDescription('root', '', [interface1])
+    cfg = Config(root)
+    cfg.ip_admin_eth0.ip_admin_eth0.append(None)
+    assert cfg.cfgimpl_get_values().has_warning() is False
+    cfg.ip_admin_eth0.netmask_admin_eth0 = ['val1']
+    assert cfg.ip_admin_eth0.netmask_admin_eth0 == ['val1']
+    assert cfg.cfgimpl_get_values().has_warning() is True
+    assert cfg.cfgimpl_get_values().get_last_warning() == 'invalid value val1 for option netmask_admin_eth0: error'
+    cfg.ip_admin_eth0.ip_admin_eth0 = ['val']
+    assert cfg.ip_admin_eth0.ip_admin_eth0 == ['val']
+    assert cfg.cfgimpl_get_values().get_last_warning() == 'invalid value val for option ip_admin_eth0: error'
diff --git a/tiramisu/option.py b/tiramisu/option.py
index 4112050..c49e5e4 100644
--- a/tiramisu/option.py
+++ b/tiramisu/option.py
@@ -473,7 +473,7 @@ class Option(BaseOption):
 
         def do_validation(_value, _index=None):
             if _value is None:
-                return True
+                return
             ret_validation = None
             try:
                 # valid with self._validator
@@ -481,6 +481,7 @@ class Option(BaseOption):
                 # if not context launch consistency validation
                 if context is not None:
                     descr._valid_consistency(self, _value, context, _index)
+                self._second_level_validation(_value)
             except ValueError as err:
                 msg = _("invalid value {0} for option {1}: {2}").format(
                     _value, self._name, err)
@@ -610,6 +611,9 @@ class Option(BaseOption):
             else:
                 self._state_callback = (callback, cllbck_prms)
 
+    def _second_level_validation(self, value):
+        pass
+
 
 class ChoiceOption(Option):
     """represents a choice out of several objects.
@@ -777,6 +781,9 @@ class IPOption(Option):
                                        only_warning=only_warning)
 
     def _validate(self, value):
+        IP('{0}/32'.format(value))
+
+    def _second_level_validation(self, value):
         ip = IP('{0}/32'.format(value))
         if not self._allow_reserved and ip.iptype() == 'RESERVED':
             raise ValueError(_("IP mustn't not be in reserved class"))
@@ -860,6 +867,9 @@ class NetworkOption(Option):
     _opt_type = 'network'
 
     def _validate(self, value):
+        IP(value)
+
+    def _second_level_validation(self, value):
         ip = IP(value)
         if ip.iptype() == 'RESERVED':
             raise ValueError(_("network shall not be in reserved class"))