Index: common/cmd_net.c
===================================================================
RCS file: /home/cvsroot/Projects/u-boot/common/cmd_net.c,v
retrieving revision 1.1.1.1
retrieving revision 1.2
diff -p -u -r1.1.1.1 -r1.2
--- common/cmd_net.c	28 Jun 2005 17:32:26 -0000	1.1.1.1
+++ common/cmd_net.c	24 Oct 2005 17:21:39 -0000	1.2
@@ -151,6 +151,17 @@ static void netboot_update_env (void)
 #endif
 }
 
+static int 
+net_check_device(void) 
+{
+	if(eth_get_dev() == NULL) {
+		printf("No network device available.\n");
+		return -1;
+	} else {
+		return 0;
+	}
+}
+
 static int
 netboot_common (proto_t proto, cmd_tbl_t *cmdtp, int argc, char *argv[])
 {
@@ -158,6 +169,9 @@ netboot_common (proto_t proto, cmd_tbl_t
 	int   rcode = 0;
 	int   size;
 
+	if (net_check_device() < 0)
+		return -1;
+
 	/* pre-set load_addr */
 	if ((s = getenv("loadaddr")) != NULL) {
 		load_addr = simple_strtoul(s, NULL, 16);
@@ -226,6 +240,9 @@ int do_ping (cmd_tbl_t *cmdtp, int flag,
 	if (argc < 2)
 		return -1;
 
+	if(net_check_device() < 0)
+		return -1;
+
 	NetPingIP = string_to_ip(argv[1]);
 	if (NetPingIP == 0) {
 		printf ("Usage:\n%s\n", cmdtp->usage);
@@ -275,6 +292,9 @@ int do_cdp (cmd_tbl_t *cmdtp, int flag, 
 {
 	int r;
 
+	if(net_check_device() < 0)
+		return -1;
+
 	r = NetLoop(CDP);
 	if (r < 0) {
 		printf("cdp failed; perhaps not a CISCO switch?\n");
@@ -296,6 +316,9 @@ U_BOOT_CMD(
 int do_sntp (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
 {
 	char *toff;
+
+	if(net_check_device() < 0)
+		return -1;
 
 	if (argc < 2) {
 		NetNtpServerIP = getenv_IPaddr ("ntpserverip");