diff --git a/staticlibs/device/com/android/net/module/util/structs/IaPrefixOption.java b/staticlibs/device/com/android/net/module/util/structs/IaPrefixOption.java
index 59d655c..176b7bc 100644
--- a/staticlibs/device/com/android/net/module/util/structs/IaPrefixOption.java
+++ b/staticlibs/device/com/android/net/module/util/structs/IaPrefixOption.java
@@ -18,6 +18,8 @@
 
 import static com.android.net.module.util.NetworkStackConstants.DHCP6_OPTION_IAPREFIX;
 
+import android.util.Log;
+
 import com.android.net.module.util.Struct;
 import com.android.net.module.util.Struct.Field;
 import com.android.net.module.util.Struct.Type;
@@ -52,6 +54,7 @@
  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  */
 public class IaPrefixOption extends Struct {
+    private static final String TAG = IaPrefixOption.class.getSimpleName();
     public static final int LENGTH = 25; // option length excluding IAprefix-options
 
     @Field(order = 0, type = Type.S16)
@@ -78,6 +81,33 @@
     }
 
     /**
+     * Check whether or not IA Prefix option in IA_PD option is valid per RFC8415#section-21.22.
+     */
+    public boolean isValid(int t2) {
+        if (preferred < 0 || valid < 0) {
+            Log.w(TAG, "IA_PD option with invalid lifetime, preferred lifetime " + preferred
+                    + ", valid lifetime " + valid);
+            return false;
+        }
+        if (preferred > valid) {
+            Log.w(TAG, "IA_PD option with preferred lifetime " + preferred
+                    + " greater than valid lifetime " + valid);
+            return false;
+        }
+        if (prefixLen > 64) {
+            Log.w(TAG, "IA_PD option with prefix length " + prefixLen
+                    + " longer than 64");
+            return false;
+        }
+        // Either preferred lifetime or t2 might be 0 which is valid, then ignore it.
+        if (preferred != 0 && t2 != 0 && preferred < t2) {
+            Log.w(TAG, "preferred lifetime " + preferred + " is smaller than T2 " + t2);
+            return false;
+        }
+        return true;
+    }
+
+    /**
      * Build an IA_PD prefix option with given specific parameters.
      */
     public static ByteBuffer build(final short length, final long preferred, final long valid,