linux/drivers/net/bonding
dingtianhong a951bc1e6b bonding: correct the MAC address for "follow" fail_over_mac policy
The "follow" fail_over_mac policy is useful for multiport devices that
either become confused or incur a performance penalty when multiple
ports are programmed with the same MAC address, but the same MAC
address still may happened by this steps for this policy:

1) echo +eth0 > /sys/class/net/bond0/bonding/slaves
   bond0 has the same mac address with eth0, it is MAC1.

2) echo +eth1 > /sys/class/net/bond0/bonding/slaves
   eth1 is backup, eth1 has MAC2.

3) ifconfig eth0 down
   eth1 became active slave, bond will swap MAC for eth0 and eth1,
   so eth1 has MAC1, and eth0 has MAC2.

4) ifconfig eth1 down
   there is no active slave, and eth1 still has MAC1, eth2 has MAC2.

5) ifconfig eth0 up
   the eth0 became active slave again, the bond set eth0 to MAC1.

Something wrong here, then if you set eth1 up, the eth0 and eth1 will have the same
MAC address, it will break this policy for ACTIVE_BACKUP mode.

This patch will fix this problem by finding the old active slave and
swap them MAC address before change active slave.

Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Tested-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-20 20:29:40 -07:00
..
Makefile bonding: add sysfs /slave dir for bond slave devices. 2014-01-17 18:51:58 -08:00
bond_3ad.c bonding: Implement user key part of port_key in an AD system. 2015-05-11 10:59:32 -04:00
bond_alb.c vlan: kill vlan_put_tag helper 2014-11-21 14:20:17 -05:00
bond_debugfs.c net: Move bonding headers under include/net 2014-11-10 13:27:49 -05:00
bond_main.c bonding: correct the MAC address for "follow" fail_over_mac policy 2015-07-20 20:29:40 -07:00
bond_netlink.c bonding: Display LACP info only to CAP_NET_ADMIN capable user 2015-06-23 03:11:52 -07:00
bond_options.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-05-23 01:22:35 -04:00
bond_procfs.c bonding: Display LACP info only to CAP_NET_ADMIN capable user 2015-06-23 03:11:52 -07:00
bond_sysfs.c bonding: Display LACP info only to CAP_NET_ADMIN capable user 2015-06-23 03:11:52 -07:00
bond_sysfs_slave.c bonding: export slave's partner_oper_port_state via sysfs and netlink 2015-06-15 16:40:24 -07:00
bonding_priv.h net/bonding: Make DRV macros private 2015-04-26 22:59:53 -04:00