diff --git a/client/test/maxadmin_test.sh b/client/test/maxadmin_test.sh
old mode 100644
new mode 100755
index 5540fc380..dd3acaaa9
--- a/client/test/maxadmin_test.sh
+++ b/client/test/maxadmin_test.sh
@@ -26,6 +26,76 @@ else
 	echo "Auth test (long option):		Passed"
 fi
 
+#
+# Test enable|disable heartbeat|root without, with invalid and with long invalid argument
+#
+for op in enable disable
+do
+for cmd in heartbeat root
+do
+	maxadmin -pskysql $op $cmd >& /dev/null
+	if [ $? -eq "1" ]; then
+	        echo "$op $cmd (missing arg):        	Failed"
+	        failure=`expr $failure + 1`
+	else
+	        passed=`expr $passed + 1`
+	        echo "$op $cmd (missing arg):		Passed"
+	fi
+
+	maxadmin -pskysql $op $cmd qwerty >& /dev/null
+	if [ $? -eq "1" ]; then
+	        echo "$op $cmd (invalid arg):		Failed"
+	        failure=`expr $failure + 1`
+	else
+	        passed=`expr $passed + 1`
+	        echo "$op $cmd (invalied arg): 		Passed"
+	fi
+
+	maxadmin -pskysql $op $cmd xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx >& /dev/null
+	if [ $? -eq "1" ]; then
+	        echo "$op $cmd (long invalid arg):	Failed"
+	        failure=`expr $failure + 1`
+	else
+	        passed=`expr $passed + 1`
+	        echo "$op $cmd (long invalid arg):	Passed"
+	fi
+done
+done
+
+#
+# Test reload dbusers with short, and long garbage and without argument
+#
+maxadmin -pskysql reload dbusers qwerty >& /dev/null
+if [ $? -eq "1" ]; then
+        echo "Reload dbusers (invalid arg):		Failed"
+        failure=`expr $failure + 1`
+else
+        passed=`expr $passed + 1`
+        echo "Reload dbusers (invalid arg):             Passed"
+fi
+
+maxadmin -pskysql reload dbusers xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx >& /dev/null
+if [ $? -eq "1" ]; then
+        echo "Reload dbusers (long invalid arg):        Failed"
+        failure=`expr $failure + 1`
+else
+        passed=`expr $passed + 1`
+        echo "Reload dbusers (long invalid arg):	Passed"
+fi
+
+
+maxadmin -pskysql reload dbusers >& /dev/null
+if [ $? -eq "1" ]; then
+        echo "Reload dbusers (missing arg):             Failed"
+        failure=`expr $failure + 1`
+else
+        passed=`expr $passed + 1`
+        echo "Reload dbusers (missing arg):         	Passed"
+fi      
+
+#
+# Test enable|disable log debug|trace|message|error
+#
 maxadmin -pskysql enable log debug >& /dev/null
 if [ $? -eq "1" ]; then
 	echo "Enable debug log:			Failed"
@@ -44,6 +114,26 @@ else
 	echo "Enable trace log:			Passed"
 fi
 
+maxadmin -pskysql enable log message >& /dev/null
+if [ $? -eq "1" ]; then
+        echo "Enable message log:                 Failed"
+        failure=`expr $failure + 1`
+else
+        passed=`expr $passed + 1`
+        echo "Enable message log:                 Passed"
+fi
+
+maxadmin -pskysql enable log error >& /dev/null
+if [ $? -eq "1" ]; then
+        echo "Enable error log:                 Failed"
+        failure=`expr $failure + 1`
+else
+        passed=`expr $passed + 1`
+        echo "Enable error log:                 Passed"
+fi
+
+
+
 maxadmin -pskysql disable log debug >& /dev/null
 if [ $? -eq "1" ]; then
 	echo "Disable debug log:			Failed"
@@ -62,6 +152,70 @@ else
 	echo "Disable trace log:			Passed"
 fi
 
+#
+# Test restart monitor|service without, with invalid and with long invalid argument
+#
+for cmd in monitor service
+do
+	maxadmin -pskysql restart $cmd >& /dev/null
+	if [ $? -eq "1" ]; then
+        	echo "Restart $cmd (missing arg):      	Failed"
+       		failure=`expr $failure + 1`
+	else
+        	passed=`expr $passed + 1`
+	        echo "Restart $cmd (missing arg):	Passed"
+	fi
+
+	maxadmin -pskysql restart $cmd xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx >& /dev/null
+	if [ $? -eq "1" ]; then
+        	echo "Restart $cmd (long invalid arg):	Failed"
+        	failure=`expr $failure + 1`
+		else
+        	passed=`expr $passed + 1`
+        	echo "Restart $cmd (long invalid arg):	Passed"
+	fi
+
+	maxadmin -pskysql restart $cmd qwerty >& /dev/null
+	if [ $? -eq "1" ]; then
+        	echo "Restart $cmd (invalid arg): 	Failed"
+        	failure=`expr $failure + 1`
+	else
+        	passed=`expr $passed + 1`
+        	echo "Restart $cmd (invalid arg):	Passed"
+	fi
+done
+
+#
+# Test set server qwerty master withaout, with invalid and with long invalid arg
+#
+maxadmin -pskysql set server qwerty >& /dev/null
+if [ $? -eq "1" ]; then
+        echo "Set server qwerty (missing arg):		Failed"
+        failure=`expr $failure + 1`
+else
+        passed=`expr $passed + 1`
+        echo "Set server (missing arg):                 Passed"
+fi
+
+maxadmin -pskysql set server qwerty mamaster >& /dev/null
+if [ $? -eq "1" ]; then
+        echo "Set server qwerty (invalid arg):		Failed"
+        failure=`expr $failure + 1`
+else
+        passed=`expr $passed + 1`
+        echo "Set server qwerty (invalid arg):		Passed"
+fi
+
+maxadmin -pskysql set server qwerty xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx >& /dev/null
+if [ $? -eq "1" ]; then
+        echo "Set server qwerty (long invalid arg):	Failed"
+        failure=`expr $failure + 1`
+else
+        passed=`expr $passed + 1`
+        echo "Set server qwerty (long invalid arg):	Passed"
+fi
+
+
 for cmd in clients dcbs filters listeners modules monitors services servers sessions threads
 do
 	maxadmin -pskysql list $cmd | grep -s '-' >& /dev/null
@@ -112,13 +266,14 @@ fi
 
 maxadmin -pskysql set server $master maint >& /dev/null
 if [ $? -eq "1" ]; then
-	echo "set server:				Failed"
+	echo "set server $master maint:			Failed"
 	failure=`expr $failure + 1`
 else
 	passed=`expr $passed + 1`
-	echo "set server:				Passed"
+	echo "set server $master maint:			Passed"
 fi
-maxadmin -pskysql list servers | grep $master | grep -s Maint >& /dev/null
+
+maxadmin -pskysql list servers | grep $master | grep -s 'Maint' >& /dev/null
 if [ $? -eq "1" ]; then
 	echo "set maintenance mode:			Failed"
 	failure=`expr $failure + 1`
@@ -126,6 +281,7 @@ else
 	passed=`expr $passed + 1`
 	echo "set maintenance mode:			Passed"
 fi
+
 maxadmin -pskysql clear server $master maint >& /dev/null
 if [ $? -eq "1" ]; then
 	echo "clear server:				Failed"
@@ -134,7 +290,7 @@ else
 	passed=`expr $passed + 1`
 	echo "clear server:				Passed"
 fi
-maxadmin -pskysql list servers | grep $master | grep -s Maint >& /dev/null
+maxadmin -pskysql list servers | grep $master | grep -s 'Maint' >& /dev/null
 if [ $? -eq "0" ]; then
 	echo "clear maintenance mode:			Failed"
 	failure=`expr $failure + 1`
@@ -156,14 +312,45 @@ for i in $dcbs
 do
 	maxadmin -pskysql show dcb $i | grep -s 'listening' >& /dev/null
 	if [ $? -eq "1" ]; then
-		echo "show dcb listeners:			Failed"
+		echo "show dcb listeners:		Failed"
 		failure=`expr $failure + 1`
 	else
 		passed=`expr $passed + 1`
-		echo "show dcb listeners:			Passed"
+		echo "show dcb listeners:		Passed"
 	fi
 done
 
+#
+# Test show dcb|eventq|eventstats|filter|monitor|server|service|session with invalid arg
+#
+for cmd in dcb eventq filter monitor server service sessions
+do
+        maxadmin -pskysql show $cmd qwerty | grep -s '-' >& /dev/null
+        if [ $? -eq "0" ]; then
+                echo "show $cmd (invalid arg):		Failed"
+                failure=`expr $failure + 1`
+        else
+                passed=`expr $passed + 1`
+                echo "show $cmd (invalid arg):		Passed"
+        fi
+done
+
+#
+# Test shutdown monitor|service with invalid extra argument
+#
+for cmd in monitor service 
+do
+        maxadmin -pskysql shutdown $cmd qwerty | grep -s '-' >& /dev/null
+        if [ $? -eq "0" ]; then
+                echo "Shutdown $cmd (invalid extra arg):Failed"
+                failure=`expr $failure + 1`
+        else
+                passed=`expr $passed + 1`
+                echo "Shutdown $cmd (invalid extra arg):Passed"
+        fi
+done
+
+
 sessions=`maxadmin -pskysql list sessions | awk -F\| '/Listener/ { if ( NF > 1 )  print $1 }'`
 if [ $? -eq "1" ]; then
 	echo "Get listener sessions:			Failed"
diff --git a/server/core/service.c b/server/core/service.c
index e0a378647..1bfa80177 100644
--- a/server/core/service.c
+++ b/server/core/service.c
@@ -1020,7 +1020,10 @@ SERV_PROTOCOL	*lptr;
 				ptr->name, lptr->protocol, 
 				(lptr && lptr->address) ? lptr->address : "*",
 				lptr->port,
-				(lptr->listener->session->state == SESSION_STATE_LISTENER_STOPPED) ? "Stopped" : "Running"
+				(!lptr->listener || 
+				!lptr->listener->session ||
+				lptr->listener->session->state == SESSION_STATE_LISTENER_STOPPED) ? 
+				"Stopped" : "Running"
 			);
 
 			lptr = lptr->next;
diff --git a/server/modules/include/debugcli.h b/server/modules/include/debugcli.h
index 0f01da519..ed650e135 100644
--- a/server/modules/include/debugcli.h
+++ b/server/modules/include/debugcli.h
@@ -52,12 +52,14 @@ typedef struct cli_instance {
  * The CLI_SESSION structure. As CLI_SESSION is created for each user that logs into
  * the DEBUG CLI.
  */
+enum { cmdbuflen=80 };
+
 typedef struct cli_session {
-	char		cmdbuf[80];	/*< The command buffer used to build up user commands */
-	int		mode;		/*< The CLI Mode for this session */
-	SESSION		*session;	/*< The gateway session */
+	char		cmdbuf[cmdbuflen]; /*< The command buffer used to build up user commands */
+	int		mode;		   /*< The CLI Mode for this session */
+	SESSION		*session;	   /*< The gateway session */
 	struct cli_session
-			*next;		/*< The next pointer for the list of sessions */
+			*next;		   /*< The next pointer for the list of sessions */
 } CLI_SESSION;
 
 /* Command line interface modes */
diff --git a/server/modules/routing/cli.c b/server/modules/routing/cli.c
index bd054f5a3..5f927cd3c 100644
--- a/server/modules/routing/cli.c
+++ b/server/modules/routing/cli.c
@@ -272,7 +272,7 @@ CLI_SESSION	*session = (CLI_SESSION *)router_session;
 	/* Extract the characters */
 	while (queue)
 	{
-		strncat(session->cmdbuf, GWBUF_DATA(queue), GWBUF_LENGTH(queue));
+		strncat(session->cmdbuf, GWBUF_DATA(queue), MIN(GWBUF_LENGTH(queue),cmdbuflen-1));
 		queue = gwbuf_consume(queue, GWBUF_LENGTH(queue));
 	}
 
diff --git a/server/modules/routing/debugcmd.c b/server/modules/routing/debugcmd.c
index 1b2da40c1..409d627dd 100644
--- a/server/modules/routing/debugcmd.c
+++ b/server/modules/routing/debugcmd.c
@@ -666,19 +666,13 @@ SERVICE		*service;
 	case ARG_TYPE_SERVICE:
 		if (mode == CLIM_USER || (rval = (unsigned long)strtol(arg, NULL, 0)) == 0)
 			rval = (unsigned long)service_find(arg);
-		
-		if (rval)
-			return rval;
-		else
-			return 0x1; /*< invalid argument */
+
+		return rval;
 	case ARG_TYPE_SERVER:
 		if (mode == CLIM_USER || (rval = (unsigned long)strtol(arg, NULL, 0)) == 0)
 			rval = (unsigned long)server_find_by_unique_name(arg);
 		
-		if (rval)
-			return rval;
-		else
-			return 0x1; /*< invalid argument */
+		return rval;
 	case ARG_TYPE_DBUSERS:
 		if (mode == CLIM_USER || (rval = (unsigned long)strtol(arg, NULL, 0)) == 0)
 		{
@@ -686,39 +680,30 @@ SERVICE		*service;
 			if (service)
 				return (unsigned long)(service->users);
 			else
-				return 1; /*< invalid argument */
+				return 0;
 		}
 		return rval;
 	case ARG_TYPE_DCB:
 		rval = (unsigned long)strtol(arg, NULL, 0);
 		if (mode == CLIM_USER && dcb_isvalid((DCB *)rval) == 0)
-			rval = 0x1; /*< invalid argument */
+			rval = 0;
 		return rval;
 	case ARG_TYPE_SESSION:
 		rval = (unsigned long)strtol(arg, NULL, 0);
 		if (mode == CLIM_USER && session_isvalid((SESSION *)rval) == 0)
 			rval = 0;
 
-		if (rval)
-			return rval;
-		else
-			return 0x1; /*< invalid argument */
+		return rval;
 	case ARG_TYPE_MONITOR:
 		if (mode == CLIM_USER || (rval = (unsigned long)strtol(arg, NULL, 0)) == 0)
 			rval = (unsigned long)monitor_find(arg);
 
-		if (rval)
-			return rval;
-		else
-			return 0x1; /*< invalid argument */
+		return rval;
 	case ARG_TYPE_FILTER:
 		if (mode == CLIM_USER || (rval = (unsigned long)strtol(arg, NULL, 0)) == 0)
 			rval = (unsigned long)filter_find(arg);
 
-		if (rval)
-			return rval;
-		else
-			return 0x1; /*< invalid argument */
+		return rval;
 	case ARG_TYPE_NUMERIC:
 		{
 			int i;
@@ -906,15 +891,12 @@ bool in_space = false;
 								break;
 							case 1:
 								arg1 = convert_arg(cli->mode, args[2],cmds[i].options[j].arg_types[0]);
-								if (arg1 == 0x1)
-								{
+
+								if (arg1)
+									cmds[i].options[j].fn(dcb, arg1);
+								else
 									dcb_printf(dcb, "Invalid argument: %s\n",
 										   args[2]);
-								}
-								else
-								{
-									cmds[i].options[j].fn(dcb, arg1);
-								}
 								break;
 							case 2:
 								arg1 = convert_arg(cli->mode, args[2],cmds[i].options[j].arg_types[0]);
@@ -971,7 +953,7 @@ bool in_space = false;
 	if (!found)
 		dcb_printf(dcb,
 			"Command '%s' not known, type help for a list of available commands\n", args[0]);
-	memset(cli->cmdbuf, 0, 80);
+	memset(cli->cmdbuf, 0, cmdbuflen);
 
 	return 1;
 }