diff --git a/arch/sim/nuse-config.c b/arch/sim/nuse-config.c
index 34500ed45dcd..1d1f5a872cfe 100644
--- a/arch/sim/nuse-config.c
+++ b/arch/sim/nuse-config.c
@@ -40,6 +40,7 @@ nuse_config_parse_interface(char *line, FILE *fp, struct nuse_config *cf)
 
 	memset(vifcf, 0, sizeof(struct nuse_vif_config));
 	vifcf->type = NUSE_VIF_RAWSOCK; /* default */
+	strcpy(vifcf->macaddr, "00:00:00:00:00:00"); /* means random */
 
 	strsplit(line, args, sizeof(args));
 
diff --git a/arch/sim/nuse.c b/arch/sim/nuse.c
index 3b10044f49af..bdd4b010d0ad 100644
--- a/arch/sim/nuse.c
+++ b/arch/sim/nuse.c
@@ -4,6 +4,7 @@
 #include <linux/sched.h>        /* struct task_struct */
 #include <uapi/linux/route.h>   /* struct rtentry */
 #include <linux/netdevice.h>
+#include <linux/etherdevice.h>	/* eth_random_addr() */
 #include <linux/inetdevice.h>
 #include <net/route.h>
 #include <net/ipconfig.h>       /* ip_route_iotcl() */
@@ -288,6 +289,15 @@ nuse_netdev_create(struct nuse_vif_config *vifcf)
 	struct SimDevice *dev = sim_dev_create(vifcf->ifname, vif, 0);
 
 	/* assign new hw address */
+	if (vifcf->mac[0] == 0 && vifcf->mac[1] == 0 && vifcf->mac[2] == 0 &&
+	    vifcf->mac[3] == 0 && vifcf->mac[4] == 0 && vifcf->mac[5] == 0) {
+		eth_random_addr(vifcf->mac);
+		((struct net_device *)dev)->addr_assign_type = NET_ADDR_RANDOM;
+		printf("mac address for %s is randomized ", vifcf->ifname);
+		printf("%02x:%02x:%02x:%02x:%02x:%02x\n",
+		       vifcf->mac[0], vifcf->mac[1], vifcf->mac[2],
+		       vifcf->mac[3], vifcf->mac[4], vifcf->mac[5]);
+	}
 	sim_dev_set_address(dev, vifcf->mac);
 	ether_setup((struct net_device *)dev);
 
diff --git a/nuse.conf b/nuse.conf
index 9a15056781fc..282462735621 100644
--- a/nuse.conf
+++ b/nuse.conf
@@ -3,13 +3,14 @@
 interface eth0
 	address 192.168.0.10
 	netmask 255.255.255.0
-	macaddr 00:01:01:01:01:01
+#	if macaddr is not specified, random mac addr is used.
 	viftype TAP
 
 interface p1p1
 	address 172.16.0.1
 	netmask 255.255.255.0
-	macaddr 00:01:01:01:01:02
+	macaddr 00:01:01:01:01:01
+#	if viftype is not specified, defualt raw socket is used.
 
 route
 	network 172.16.1.0