On 07/16/2015 10:30 AM, Ding Tianhong wrote: > 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 <dingtianh...@huawei.com> > --- > drivers/net/bonding/bond_main.c | 20 ++++++++++++++++++++ > 1 file changed, 20 insertions(+) >
This doesn't seem to be true: ~# cat /sys/class/net/bond0/bonding/fail_over_mac follow 2 root@debian:~# ip l sh eth1 3: eth1: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master bond0 state UP mode DEFAULT group default qlen 1000 link/ether 52:54:00:3f:47:69 brd ff:ff:ff:ff:ff:ff root@debian:~# ip l sh eth2 4: eth2: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master bond0 state UP mode DEFAULT group default qlen 1000 link/ether 52:54:00:4f:a5:99 brd ff:ff:ff:ff:ff:ff root@debian:~# ip l sh bond0 26: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default link/ether 52:54:00:3f:47:69 brd ff:ff:ff:ff:ff:ff *eth1 is the first and active slave and bond0 has taken its mac. Now trying your steps: Step 3) (bringing down the active eth1) root@debian:~# ip l set eth1 down root@debian:~# ip l sh bond0 26: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default link/ether 52:54:00:3f:47:69 brd ff:ff:ff:ff:ff:ff root@debian:~# ip l sh eth1 3: eth1: <BROADCAST,MULTICAST,SLAVE> mtu 1500 qdisc pfifo_fast master bond0 state DOWN mode DEFAULT group default qlen 1000 link/ether 52:54:00:4f:a5:99 brd ff:ff:ff:ff:ff:ff root@debian:~# ip l sh eth2 4: eth2: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master bond0 state UP mode DEFAULT group default qlen 1000 link/ether 52:54:00:3f:47:69 brd ff:ff:ff:ff:ff:ff *The mac addresses of eth1 and eth2 are correctly swapped, so far so good. Step 4) (bringing down the active eth2) root@debian:~# ip l set eth2 down 3: eth1: <BROADCAST,MULTICAST,SLAVE> mtu 1500 qdisc pfifo_fast master bond0 state DOWN mode DEFAULT group default qlen 1000 link/ether 52:54:00:4f:a5:99 brd ff:ff:ff:ff:ff:ff 4: eth2: <BROADCAST,MULTICAST,SLAVE> mtu 1500 qdisc pfifo_fast master bond0 state DOWN mode DEFAULT group default qlen 1000 link/ether 52:54:00:3f:47:69 brd ff:ff:ff:ff:ff:ff 26: bond0: <NO-CARRIER,BROADCAST,MULTICAST,MASTER,UP> mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default link/ether 52:54:00:3f:47:69 brd ff:ff:ff:ff:ff:ff *eth2 has kept the mac address of the bond and they're both down now Step 5) (bring eth1 up again and observe the macs) ~# ip l set eth1 up 3: eth1: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master bond0 state UP mode DEFAULT group default qlen 1000 link/ether 52:54:00:3f:47:69 brd ff:ff:ff:ff:ff:ff 4: eth2: <BROADCAST,MULTICAST,SLAVE> mtu 1500 qdisc pfifo_fast master bond0 state DOWN mode DEFAULT group default qlen 1000 link/ether 52:54:00:4f:a5:99 brd ff:ff:ff:ff:ff:ff 26: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default link/ether 52:54:00:3f:47:69 brd ff:ff:ff:ff:ff:ff *The macs are correctly swapped and there's no such bug. Step 6(?) bring eth2 up ~# ip l set eth2 up 3: eth1: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master bond0 state UP mode DEFAULT group default qlen 1000 link/ether 52:54:00:3f:47:69 brd ff:ff:ff:ff:ff:ff 4: eth2: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master bond0 state UP mode DEFAULT group default qlen 1000 link/ether 52:54:00:4f:a5:99 brd ff:ff:ff:ff:ff:ff 26: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default link/ether 52:54:00:3f:47:69 brd ff:ff:ff:ff:ff:ff *Still correct. Also the mac address that gets set is dev_addr which is changed when the swapping is done, if you'd like to get the original mac address you should be using slave->perm_hwaddr. Cheers, Nik -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html