diff --git a/DebugCmd.c b/DebugCmd.c
index 96bc20a..2495bee 100644
--- a/DebugCmd.c
+++ b/DebugCmd.c
@@ -914,7 +914,7 @@ void DebugCmdRestoreFactory(int argc, char *argv[])
 static void DebugCmdUpload(int argc, char *argv[])
 {
 	DBG_LOG("\r\n");
-	if(strcmp(argv[1], "?") == 0) {
+	if(argc > 1 && strcmp(argv[1], "?") == 0) {
 		DBG_LOG("Debug Cmd: up\r\n");
 		DBG_LOG("  brief --> Upload current gateway status to server.\r\n\r\n");
 		return;
@@ -953,7 +953,7 @@ static void DebugCmdUpload(int argc, char *argv[])
 static void DebugCmdRegister(int argc, char *argv[])
 {
 	DBG_LOG("\r\n");
-	if(strcmp(argv[1], "?") == 0) {
+	if(argc > 1 && strcmp(argv[1], "?") == 0) {
 		DBG_LOG("Debug Cmd: reg\r\n");
 		DBG_LOG("  brief --> Re-register to the server.\r\n\r\n");
 		return;
@@ -1336,8 +1336,8 @@ static void DebugCmdEthNet(int argc, char *argv[])
 			DBG_LOG("Please switch to ETH mode first using 'comm eth' command.\r\n");
 			return;
 		}
+    GateWay->SvrRegFlag = false;
 		ETHReset();
-		ETHResetEx();
 		DBG_LOG("EthNet parameters saved and ETH module restarting...\r\n");
 		return;
 	}
@@ -1363,6 +1363,10 @@ static void DebugCmdEthNet(int argc, char *argv[])
 	}
 
 	if(strcmp(argv[1], "ip") == 0) {
+		if(argc < 3) {
+			DBG_LOG("EthCmd: Missing IP address\r\n");
+			return;
+		}
 		int ret = sscanf(argv[2], "%d.%d.%d.%d", &IP[0], &IP[1], &IP[2], &IP[3]);
 		if(ret != 4) {
 			DBG_LOG("EthCmd: Invalid IP format, use x.x.x.x\r\n");
@@ -1381,6 +1385,10 @@ static void DebugCmdEthNet(int argc, char *argv[])
 	}
 
 	if(strcmp(argv[1], "port") == 0) {
+		if(argc < 3) {
+			DBG_LOG("EthCmd: Missing port number\r\n");
+			return;
+		}
 		int port = atoi(argv[2]);
 		if(port <= 0 || port > 65535) {
 			DBG_LOG("EthCmd: Port out of range (1-65535).\r\n");
@@ -1392,6 +1400,10 @@ static void DebugCmdEthNet(int argc, char *argv[])
 	}
 
 	if(strcmp(argv[1], "wmode") == 0) {
+		if(argc < 3) {
+			DBG_LOG("EthCmd: Missing work mode (tcp/udp)\r\n");
+			return;
+		}
 		if(strcmp(argv[2], "tcp") == 0) {
 			GateWay->ConfigPara.EthNet.WorkMode = ETH_MODE_TCP_CLIENT;
 			DBG_LOG("WorkMode set to TCP_CLIENT.\r\n");
@@ -1407,6 +1419,10 @@ static void DebugCmdEthNet(int argc, char *argv[])
 	}
 
 	if(strcmp(argv[1], "mask") == 0) {
+		if(argc < 3) {
+			DBG_LOG("EthCmd: Missing subnet mask\r\n");
+			return;
+		}
 		int ret = sscanf(argv[2], "%d.%d.%d.%d", &IP[0], &IP[1], &IP[2], &IP[3]);
 		if(ret != 4) {
 			DBG_LOG("EthCmd: Invalid mask format, use x.x.x.x\r\n");
@@ -1425,6 +1441,10 @@ static void DebugCmdEthNet(int argc, char *argv[])
 	}
 
 	if(strcmp(argv[1], "gw") == 0) {
+		if(argc < 3) {
+			DBG_LOG("EthCmd: Missing gateway address\r\n");
+			return;
+		}
 		int ret = sscanf(argv[2], "%d.%d.%d.%d", &IP[0], &IP[1], &IP[2], &IP[3]);
 		if(ret != 4) {
 			DBG_LOG("EthCmd: Invalid gateway format, use x.x.x.x\r\n");
@@ -1443,6 +1463,10 @@ static void DebugCmdEthNet(int argc, char *argv[])
 	}
 
 	if(strcmp(argv[1], "dip") == 0) {
+		if(argc < 3) {
+			DBG_LOG("EthCmd: Missing destination IP address\r\n");
+			return;
+		}
 		int ret = sscanf(argv[2], "%d.%d.%d.%d", &IP[0], &IP[1], &IP[2], &IP[3]);
 		if(ret != 4) {
 			DBG_LOG("EthCmd: Invalid destination IP format, use x.x.x.x\r\n");
@@ -1461,6 +1485,10 @@ static void DebugCmdEthNet(int argc, char *argv[])
 	}
 
 	if(strcmp(argv[1], "dport") == 0) {
+		if(argc < 3) {
+			DBG_LOG("EthCmd: Missing destination port\r\n");
+			return;
+		}
 		int port = atoi(argv[2]);
 		if(port <= 0 || port > 65535) {
 			DBG_LOG("EthCmd: DestPort out of range (1-65535).\r\n");