diff --git a/crude_engine/schemas/interface.yaml b/crude_engine/schemas/interface.yaml
index d7d4d84..de63e78 100644
--- a/crude_engine/schemas/interface.yaml
+++ b/crude_engine/schemas/interface.yaml
@@ -28,6 +28,7 @@ methods:
     type: dict
     primary_key: name
     key_map: ifindex
+    index_filter: '^\d+/\d+$'
     # SSH identity from show interface counters (ifdescr), not show port ifname
     attributes:
       name: