Fix DHCP relay command format

Change-Id: I7375fa998fbe9e01c81efefa7f70f1f88a2d6d69
diff --git a/utils/misc/src/main/java/org/onlab/packet/IpAddress.java b/utils/misc/src/main/java/org/onlab/packet/IpAddress.java
index 75b5b2f..3725573 100644
--- a/utils/misc/src/main/java/org/onlab/packet/IpAddress.java
+++ b/utils/misc/src/main/java/org/onlab/packet/IpAddress.java
@@ -341,7 +341,7 @@
     /**
      * Check if this IP address is a multicast address.
      *
-     * @return true if this address a multicast address
+     * @return true if this address is a multicast address
      */
     public boolean isMulticast() {
         return isIp4() ?
@@ -349,6 +349,17 @@
                 Ip6Prefix.IPV6_MULTICAST_PREFIX.contains(this.getIp6Address());
     }
 
+    /**
+     * Check if this IP address is a link-local address.
+     *
+     * @return true if this address is a link-local address
+     */
+    public boolean isLinkLocal() {
+        return isIp4() ?
+                Ip4Prefix.IPV4_LINK_LOCAL_PREFIX.contains(this.getIp4Address()) :
+                Ip6Prefix.IPV6_LINK_LOCAL_PREFIX.contains(this.getIp6Address());
+    }
+
     @Override
     public int compareTo(IpAddress o) {
         // Compare first the version
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;