diff --git a/scripts/inventory_rules.py b/scripts/inventory_rules.py
index d475988..c7fa77d 100644
--- a/scripts/inventory_rules.py
+++ b/scripts/inventory_rules.py
@@ -325,10 +325,20 @@ def deriver_nomenclature(fonction: str, seq: int, nomenclature: dict) -> dict |
     # retro-compatible (instances sans index, bacs a sable). 1 chiffre -> 9 instances
     # prod federables avec un VMID a 5 chiffres ; elargir l'index pour davantage.
     index = nomenclature.get("index", 9)
+    hote = svc * 10 + int(seq)
+    # Schema du VMID. 'ip-miroir' (opt-in) : 9 chiffres mnemotechniques encodant
+    # index + VLAN + octet-hote + sequence -> le VMID contient litteralement l'IP
+    # (10.(10+index).VLAN.hote) et le tenant. 'compact' (defaut, retro-compatible) :
+    # index.categorie.service.sequence (largeur variable, VMID des instances existantes).
+    schema = nomenclature.get("vmid_schema", "compact")
+    if schema == "ip-miroir":
+        vmid = f"{index}{int(c.get('vlan', 0)):03d}{hote:03d}{int(seq):02d}"
+    else:
+        vmid = f"{index}{cat}{svc}{int(seq):02d}"
     return {
-        "vmid": f"{index}{cat}{svc}{int(seq):02d}",
+        "vmid": vmid,
         "vlan": c.get("vlan"),
-        "adresse_ip": f"{base3}.{svc * 10 + int(seq)}",
+        "adresse_ip": f"{base3}.{hote}",
         "passerelle": c.get("passerelle"),
         "cidr": nomenclature.get("cidr_hote", 24),
     }