diff --git a/topologie/models.py b/topologie/models.py
index e469eefb..441a9f78 100644
--- a/topologie/models.py
+++ b/topologie/models.py
@@ -1,7 +1,17 @@
 from django.db import models
 from django.contrib.contenttypes.models import ContentType
 from django.contrib.contenttypes.fields import GenericForeignKey
+from django.core.exceptions import ValidationError
 
+def make_port_related(port):
+    related_port = port.related
+    related_port.related = port
+    related_port.save()
+    
+def clean_port_related(port):
+    related_port = port.related_port
+    related_port.related = None
+    related_port.save()
 
 class Switch(models.Model):
     building = models.CharField(max_length=10)
@@ -20,22 +30,23 @@ class Port(models.Model):
     details = models.CharField(max_length=255, blank=True)
     room = models.ForeignKey('Room', on_delete=models.PROTECT, blank=True, null=True)
     machine_interface = models.OneToOneField('machines.Interface', on_delete=models.PROTECT, blank=True, null=True)
+    related = models.OneToOneField('self', null=True, blank=True, related_name='related_port')
 
     class Meta:
-        unique_together = ('_content_type', '_object_id')
+        unique_together = ('switch', 'port')
 
-    _content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE, blank=True, null=True)
-    _object_id = models.PositiveIntegerField(blank=True, null=True)
-    goto = GenericForeignKey('_content_type', '_object_id')
-
-    @property
-    def comefrom(self):
-        ctype = ContentType.objects.get_for_model(self.__class__)
-        try:
-            event = Port.objects.get(_content_type__pk=ctype.id, _object_id=self.id)
-        except:
-            return None
-        return event
+    def clean(self):
+        if self.room and self.machine_interface or self.room and self.related or self.machine_interface and self.related:
+            raise ValidationError("Chambre, interface et related_port sont mutuellement exclusifs")
+        if self.related==self:
+            raise ValidationError("On ne peut relier un port à lui même")
+        if self.related and not self.related.related:
+            if self.related.machine_interface or self.related.room:
+                raise ValidationError("Le port relié est déjà occupé, veuillez le libérer avant de créer une relation")
+            else:
+                make_port_related(self)
+        elif hasattr(self, 'related_port'):
+            clean_port_related(self)
 
     def __str__(self):
         return str(self.switch) + " - " + str(self.port)