diff --git a/api/serializers.py b/api/serializers.py
index 4605b79b..f06e1b92 100644
--- a/api/serializers.py
+++ b/api/serializers.py
@@ -696,7 +696,7 @@ class RoleSerializer(NamespacedHMSerializer):
 
     class Meta:
         model = machines.Role
-        fields = ('role_type', 'servers')
+        fields = ('role_type', 'servers', 'specific_role')
 
 
 class VlanPortSerializer(NamespacedHMSerializer):
diff --git a/machines/migrations/0094_role_specific_role.py b/machines/migrations/0094_role_specific_role.py
new file mode 100644
index 00000000..73cade7b
--- /dev/null
+++ b/machines/migrations/0094_role_specific_role.py
@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.7 on 2018-07-11 16:49
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('machines', '0093_merge_20180710_0226'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='role',
+            name='specific_role',
+            field=models.CharField(blank=True, choices=[('dhcp-server', 'dhcp-server'), ('switch-conf-server', 'switch-conf-server'), ('dns-recursif-server', 'dns-recursif-server'), ('ntp-server', 'ntp-server'), ('radius-server', 'radius-server'), ('ntp-server', 'ntp-server'), ('log-server', 'log-server'), ('ldap-master-server', 'ldap-master-server'), ('ldap-backup-server', 'ldap-backup-server'), ('smtp-server', 'smtp-server'), ('postgresql-server', 'postgresql-server'), ('mysql-server', 'mysql-server'), ('sql-client', 'sql-client'), ('gateway', 'gateway')], max_length=32, null=True),
+        ),
+    ]
diff --git a/machines/models.py b/machines/models.py
index 212d65e8..d5cdc5a1 100644
--- a/machines/models.py
+++ b/machines/models.py
@@ -1652,6 +1652,19 @@ class Role(RevMixin, AclMixin, models.Model):
             machine__interface__role=cls.objects.filter(specific_role=roletype)
         )
 
+    @classmethod
+    def get_instance(cls, machineid, *_args, **_kwargs):
+        """Get the Machine instance with machineid.
+        :param userid: The id
+        :return: The user
+        """
+        return cls.objects.get(pk=machineid)
+
+    @classmethod
+    def interface_for_roletype(cls, roletype):
+        """Return interfaces for a roletype"""
+        return Interface.objects.filter(role=cls.objects.filter(specific_role=roletype))
+
     def save(self, *args, **kwargs):
         super(Role, self).save(*args, **kwargs)
 
diff --git a/preferences/models.py b/preferences/models.py
index 65db5d97..c1d19a23 100644
--- a/preferences/models.py
+++ b/preferences/models.py
@@ -231,11 +231,27 @@ class OptionalTopologie(AclMixin, PreferencesModel):
         from topologie.models import Switch
         return Switch.objects.filter(automatic_provision=True)
 
+    @cached_property   
+    def switchs_management_interface(self):
+        """Return the ip of the interface that the switch have to contact to get it's config"""
+        if self.switchs_ip_type:
+            from machines.models import Role, Interface
+            return Interface.objects.filter(machine__interface__in=Role.interface_for_roletype("switch-conf-server")).filter(type__ip_type=self.switchs_ip_type).first()
+        else:
+            return None
+
+    @cached_property   
+    def switchs_management_interface_ip(self):
+        """Same, but return the ipv4"""
+        if not self.switchs_management_interface:
+            return None
+        return self.switchs_management_interface.ipv4
+
     @cached_property
     def provision_switchs_enabled(self):
         """Return true if all settings are ok : switchs on automatic provision,
         ip_type"""
-        return bool(self.provisioned_switchs and self.switchs_ip_type and SwitchManagementCred.objects.filter(default_switch=True).exists())
+        return bool(self.provisioned_switchs and self.switchs_ip_type and SwitchManagementCred.objects.filter(default_switch=True).exists() and self.switchs_management_interface_ip)
 
     class Meta:
         permissions = (
diff --git a/preferences/templates/preferences/display_preferences.html b/preferences/templates/preferences/display_preferences.html
index 85c4c5cd..5ea1f0e6 100644
--- a/preferences/templates/preferences/display_preferences.html
+++ b/preferences/templates/preferences/display_preferences.html
@@ -152,6 +152,10 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 	    <th>Plage d'ip de management des switchs</th>
 	    <td>{{ topologieoptions.switchs_ip_type }} {% if topologieoptions.switchs_ip_type %}<span class="label label-success"> OK{% else %}<span class="label label-danger">Manquant{% endif %}</span></td>
 	</tr>
+	<tr>	
+            <th>Serveur des config des switchs</th>
+	    <td>{{ topologieoptions.switchs_management_interface }} {% if topologieoptions.switchs_management_interface %} - {{ topologieoptions.switchs_management_interface_ip }}  <span class="label label-success"> OK{% else %}<span class="label label-danger">Manquant{% endif %}</span></td>
+	</tr>
     </table>
 
        <h6>Creds de management des switchs</h6>