- for (j = 0; j < port->n_ifaces; j++) {
- struct iface *iface = port->ifaces[j];
- uint8_t iface_ea[ETH_ADDR_LEN];
+
+ /* Choose the MAC address to represent the port. */
+ iface_ea_u64 = cfg_get_mac(0, "port.%s.mac", port->name);
+ if (iface_ea_u64) {
+ /* User specified explicitly. */
+ eth_addr_from_uint64(iface_ea_u64, iface_ea);
+ } else {
+ /* Choose the interface whose MAC address will represent the port.
+ * The Linux kernel bonding code always chooses the MAC address of
+ * the first slave added to a bond, and the Fedora networking
+ * scripts always add slaves to a bond in alphabetical order, so
+ * for compatibility we choose the interface with the name that is
+ * first in alphabetical order. */
+ iface = port->ifaces[0];
+ for (j = 1; j < port->n_ifaces; j++) {
+ struct iface *candidate = port->ifaces[j];
+ if (strcmp(candidate->name, iface->name) < 0) {
+ iface = candidate;
+ }
+ }
+
+ /* The local port doesn't count (since we're trying to choose its
+ * MAC address anyway). Other internal ports don't count because
+ * we really want a physical MAC if we can get it, and internal
+ * ports typically have randomly generated MACs. */