diff --git a/mfwd/src/main/java/org/onosproject/mfwd/cli/McastJoinCommand.java b/mfwd/src/main/java/org/onosproject/mfwd/cli/McastJoinCommand.java
index 5c78cbd..5172691 100644
--- a/mfwd/src/main/java/org/onosproject/mfwd/cli/McastJoinCommand.java
+++ b/mfwd/src/main/java/org/onosproject/mfwd/cli/McastJoinCommand.java
@@ -17,6 +17,7 @@
 
 import org.apache.karaf.shell.commands.Argument;
 import org.apache.karaf.shell.commands.Command;
+import org.onlab.packet.IpPrefix;
 import org.onosproject.cli.AbstractShellCommand;
 
 import org.onosproject.mfwd.impl.McastRouteBase;
@@ -52,7 +53,24 @@
     @Override
     protected void execute() {
         McastRouteTable mrib = McastRouteTable.getInstance();
+        IpPrefix mcast = IpPrefix.valueOf("224.0.0.0/4");
+        IpPrefix saddr = IpPrefix.valueOf(sAddr);
+        if (mcast.contains(saddr)) {
+            print("Error: the source address " + sAddr + " must be an IPv4 unicast address");
+            return;
+        }
+
+        IpPrefix gaddr = IpPrefix.valueOf(gAddr);
+        if (!mcast.contains(gaddr)) {
+            print("Error: " + gAddr + " must be a multicast group address");
+            return;
+        }
+
         McastRouteBase mr = mrib.addRoute(sAddr, gAddr);
+        if (mr == null) {
+            print("Error: unable to save the multicast state");
+            return;
+        }
 
         // Port format "of:0000000000000023/4"
         if (ingressPort != null) {
@@ -60,6 +78,12 @@
             log.debug("Ingress port provided: " + inCP);
             String [] cp = inCP.split("/");
             mr.addIngressPoint(cp[0], Long.parseLong(cp[1]));
+        } else {
+            return;
+        }
+
+        if (ports == null) {
+            return;
         }
 
         for (int i = 0; i < ports.length; i++) {