diff --git a/lcpng_interface.c b/lcpng_interface.c
index c27fb70..4e61f08 100644
--- a/lcpng_interface.c
+++ b/lcpng_interface.c
@@ -782,6 +782,14 @@ lcp_itf_pair_create (u32 phy_sw_if_index, u8 *host_if_name,
   const vnet_sw_interface_t *sw;
   const vnet_hw_interface_t *hw;
   lcp_itf_pair_t *lip;
+  index_t lipi;
+
+  lipi = lcp_itf_pair_find_by_phy (phy_sw_if_index);
+  if (lipi != INDEX_INVALID)
+    {
+      LCP_IF_ERROR ("pair_create: already created");
+      return VNET_API_ERROR_VALUE_EXIST;
+    }
 
   if (!vnet_sw_if_index_is_api_valid (phy_sw_if_index))
     {