diff --git a/vl.c b/vl.c
--- a/vl.c
+++ b/vl.c
@@ -1665,7 +1665,7 @@ static int net_tun_init(NetDriverState *
         if (pid == 0) {
             char MAC[24];
             memset(MAC,0,24);
-            sprintf(MAC, "%X.%X.%X.%X.%X.%X",  nd->macaddr[0],nd->macaddr[1], nd->macaddr[2], nd->macaddr[3],nd->macaddr[4],nd->macaddr[5]);
+            sprintf(MAC, "%X:%X:%X:%X:%X:%X",  nd->macaddr[0],nd->macaddr[1], nd->macaddr[2], nd->macaddr[3],nd->macaddr[4],nd->macaddr[5]);
             parg = args;
             *parg++ = network_script;
             *parg++ = nd->ifname;
@@ -3233,7 +3233,6 @@ int main(int argc, char **argv)
                  }
                  /* set the defaults */
                   while (j++ < nb_nics-1) {
-                     printf("setting default for NIC %d",j);
                      for(i = 0; i < 6; i++) {
                          if (i == 5)
                              macaddrs[j][i] = macaddr[i]+j;