diff --git a/core/api/src/main/java/org/onosproject/net/PortNumber.java b/core/api/src/main/java/org/onosproject/net/PortNumber.java
index e10695f..9d1d7b7 100644
--- a/core/api/src/main/java/org/onosproject/net/PortNumber.java
+++ b/core/api/src/main/java/org/onosproject/net/PortNumber.java
@@ -49,6 +49,8 @@
     static final long LOCAL_NUMBER = -2L;
     static final long ANY_NUMBER = -1L;
 
+    public static final long NO_DISPLAY_NUMBER = -1L;
+
     /**
      * Logical PortNumbers.
      */
@@ -251,7 +253,11 @@
             return decodeLogicalPort();
         } else if (hasName()) {
             // named port
-            return String.format("[%s](%d)", name, number);
+            if (number == NO_DISPLAY_NUMBER) {
+                return String.format("[%s]", name);
+            } else {
+                return String.format("[%s](%d)", name, number);
+            }
         } else {
             // unsigned decimal string
             return name;