diff --git a/schemas/extensions.yml b/schemas/extensions.yml
index 87e20fd..b726e27 100644
--- a/schemas/extensions.yml
+++ b/schemas/extensions.yml
@@ -85,15 +85,19 @@ nodes:
         kind: Parent
       - name: local_device
         peer: InfraDevice
+        identifier: underlaylink__local_device
         cardinality: one
       - name: local_interface
         peer: InfraInterfaceEthernet
+        identifier: underlaylink__local_interface
         cardinality: one
       - name: remote_device
         peer: InfraDevice
+        identifier: underlaylink__remote_device
         cardinality: one
       - name: remote_interface
         peer: InfraInterfaceEthernet
+        identifier: underlaylink__remote_interface
         cardinality: one
 
   # =============================================================================