[Bridge] Bridge MAC selection

Dietmar Maurer dietmar at proxmox.com
Wed Jun 11 01:27:54 PDT 2008

Hi all,

We provid a management plattform for virtual machines (pve.proxmox.com),
use a bridge access the network.

Currently the system choose the lowest MAC for the purposes of STP 
and also assigns this MAC to the bridge. This is a problem because the 
Bridge MAC changes when we start/stop virtual machines - leading to 
Network outage for several seconds.

Using the first (insteasd of lowest) MAC would avoid the problem. So are

There any side effects with the following patch?

--- br_stp_if.c.org     2008-06-11 09:15:16.000000000 +0200
+++ br_stp_if.c 2008-06-11 09:44:53.000000000 +0200
@@ -217,10 +217,7 @@
        struct net_bridge_port *p;

        list_for_each_entry(p, &br->port_list, list) {
-               if (addr == br_mac_zero ||
-                   memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
-                       addr = p->dev->dev_addr;
+               addr = p->dev->dev_addr;

        if (compare_ether_addr(br->bridge_id.addr, addr))

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