diff -rupN libvirt-0.4.1.orig/src/bridge.c libvirt-0.4.1.new/src/bridge.c
--- libvirt-0.4.1.orig/src/bridge.c	2008-02-28 06:16:21.000000000 -0500
+++ libvirt-0.4.1.new/src/bridge.c	2008-03-13 11:25:12.000000000 -0400
@@ -313,7 +313,6 @@ brDeleteInterface(brControl *ctl ATTRIBU
 int
 brAddTap(brControl *ctl,
          const char *bridge,
-         unsigned char *macaddr,
          char *ifname,
          int maxlen,
          int *tapfd)
@@ -357,18 +356,6 @@ brAddTap(brControl *ctl,
         }
 
         if (ioctl(fd, TUNSETIFF, &try) == 0) {
-            struct ifreq addr;
-            memset(&addr, 0, sizeof(addr));
-            memcpy(addr.ifr_hwaddr.sa_data, macaddr, 6);
-            addr.ifr_hwaddr.sa_family = ARPHRD_ETHER;
-
-            /* Device actually starts in 'UP' state, but it
-             * needs to be down to set the MAC addr
-             */
-            if ((errno = brSetInterfaceUp(ctl, try.ifr_name, 0)))
-                goto error;
-            if (ioctl(fd, SIOCSIFHWADDR, &addr) != 0)
-                goto error;
             if ((errno = brAddInterface(ctl, bridge, try.ifr_name)))
                 goto error;
             if ((errno = brSetInterfaceUp(ctl, try.ifr_name, 1)))
diff -rupN libvirt-0.4.1.orig/src/bridge.h libvirt-0.4.1.new/src/bridge.h
--- libvirt-0.4.1.orig/src/bridge.h	2008-02-28 06:16:21.000000000 -0500
+++ libvirt-0.4.1.new/src/bridge.h	2008-03-13 11:25:12.000000000 -0400
@@ -62,7 +62,6 @@ int     brDeleteInterface       (brContr
 
 int     brAddTap                (brControl *ctl,
                                  const char *bridge,
-                                 unsigned char *mac,
                                  char *ifname,
                                  int maxlen,
                                  int *tapfd);
diff -rupN libvirt-0.4.1.orig/src/qemu_conf.c libvirt-0.4.1.new/src/qemu_conf.c
--- libvirt-0.4.1.orig/src/qemu_conf.c	2008-03-13 11:24:39.000000000 -0400
+++ libvirt-0.4.1.new/src/qemu_conf.c	2008-03-13 11:25:12.000000000 -0400
@@ -1540,7 +1540,6 @@ qemudNetworkIfaceConnect(virConnectPtr c
     }
 
     if ((err = brAddTap(driver->brctl, brname,
-                        net->mac,
                         ifname, BR_IFNAME_MAXLEN, &tapfd))) {
         qemudReportError(conn, NULL, NULL, VIR_ERR_INTERNAL_ERROR,
                          "Failed to add tap interface '%s' to bridge '%s' : %s",
@@ -1548,7 +1547,9 @@ qemudNetworkIfaceConnect(virConnectPtr c
         goto error;
     }
 
-    snprintf(tapfdstr, sizeof(tapfdstr), "tap,fd=%d,script=,vlan=%d", tapfd, vlan);
+    snprintf(tapfdstr, sizeof(tapfdstr),
+             "tap,fd=%d,script=,vlan=%d,ifname=%s",
+             tapfd, vlan, ifname);
 
     if (!(retval = strdup(tapfdstr)))
         goto no_memory;