Fix DHCP relay command format

Change-Id: I7375fa998fbe9e01c81efefa7f70f1f88a2d6d69
diff --git a/utils/misc/src/main/java/org/onlab/packet/IpPrefix.java b/utils/misc/src/main/java/org/onlab/packet/IpPrefix.java
index 7f50327..07539af 100644
--- a/utils/misc/src/main/java/org/onlab/packet/IpPrefix.java
+++ b/utils/misc/src/main/java/org/onlab/packet/IpPrefix.java
@@ -48,6 +48,14 @@
      * An IpPrefix that contains all IPv6 multicast addresses.
      */
     public static final IpPrefix IPV6_MULTICAST_PREFIX = IpPrefix.valueOf("ff00::/8");
+    /**
+     * An IpPrefix that contains all IPv4 link local addresses.
+     */
+    public static final IpPrefix IPV4_LINK_LOCAL_PREFIX = IpPrefix.valueOf("169.254.0.0/16");
+    /**
+     * An IpPrefix that contains all IPv6 link local addresses.
+     */
+    public static final IpPrefix IPV6_LINK_LOCAL_PREFIX = IpPrefix.valueOf("fe80::/64");
 
     private final IpAddress address;
     private final short prefixLength;