MPLS label selector and treatment

Change-Id: Id1fba1e04155e6d97de4c8fd95573641537f1b7a
diff --git a/utils/misc/src/main/java/org/onlab/packet/Ethernet.java b/utils/misc/src/main/java/org/onlab/packet/Ethernet.java
index 3519338..0058e16 100644
--- a/utils/misc/src/main/java/org/onlab/packet/Ethernet.java
+++ b/utils/misc/src/main/java/org/onlab/packet/Ethernet.java
@@ -37,6 +37,8 @@
     public static final short TYPE_LLDP = (short) 0x88cc;
     public static final short TYPE_BSN = (short) 0x8942;
     public static final short VLAN_UNTAGGED = (short) 0xffff;
+    public static final short MPLS_UNICAST = (short) 0x8847;
+    public static final short MPLS_MULTICAST = (short) 0x8848;
     public static final short DATALAYER_ADDRESS_LENGTH = 6; // bytes
     public static Map<Short, Class<? extends IPacket>> etherTypeClassMap;