-3.4 Configuring Bonding Manually via Sysfs
-------------------------------------------
-
- Starting with version 3.0, Channel Bonding may be configured
-via the sysfs interface. This interface allows dynamic configuration
-of all bonds in the system without unloading the module. It also
-allows for adding and removing bonds at runtime. Ifenslave is no
-longer required, though it is still supported.
-
- Use of the sysfs interface allows you to use multiple bonds
-with different configurations without having to reload the module.
-It also allows you to use multiple, differently configured bonds when
-bonding is compiled into the kernel.
-
- You must have the sysfs filesystem mounted to configure
-bonding this way. The examples in this document assume that you
-are using the standard mount point for sysfs, e.g. /sys. If your
-sysfs filesystem is mounted elsewhere, you will need to adjust the
-example paths accordingly.
-
-Creating and Destroying Bonds
------------------------------
-To add a new bond foo:
-# echo +foo > /sys/class/net/bonding_masters
-
-To remove an existing bond bar:
-# echo -bar > /sys/class/net/bonding_masters
-
-To show all existing bonds:
-# cat /sys/class/net/bonding_masters
-
-NOTE: due to 4K size limitation of sysfs files, this list may be
-truncated if you have more than a few hundred bonds. This is unlikely
-to occur under normal operating conditions.
-
-Adding and Removing Slaves
---------------------------
- Interfaces may be enslaved to a bond using the file
-/sys/class/net/<bond>/bonding/slaves. The semantics for this file
-are the same as for the bonding_masters file.
-
-To enslave interface eth0 to bond bond0:
-# ifconfig bond0 up
-# echo +eth0 > /sys/class/net/bond0/bonding/slaves
-
-To free slave eth0 from bond bond0:
-# echo -eth0 > /sys/class/net/bond0/bonding/slaves
-
- NOTE: The bond must be up before slaves can be added. All
-slaves are freed when the interface is brought down.
-
- When an interface is enslaved to a bond, symlinks between the
-two are created in the sysfs filesystem. In this case, you would get
-/sys/class/net/bond0/slave_eth0 pointing to /sys/class/net/eth0, and
-/sys/class/net/eth0/master pointing to /sys/class/net/bond0.
-
- This means that you can tell quickly whether or not an
-interface is enslaved by looking for the master symlink. Thus:
-# echo -eth0 > /sys/class/net/eth0/master/bonding/slaves
-will free eth0 from whatever bond it is enslaved to, regardless of
-the name of the bond interface.
-
-Changing a Bond's Configuration
--------------------------------
- Each bond may be configured individually by manipulating the
-files located in /sys/class/net/<bond name>/bonding
-
- The names of these files correspond directly with the command-
-line parameters described elsewhere in in this file, and, with the
-exception of arp_ip_target, they accept the same values. To see the
-current setting, simply cat the appropriate file.
-
- A few examples will be given here; for specific usage
-guidelines for each parameter, see the appropriate section in this
-document.
-
-To configure bond0 for balance-alb mode:
-# ifconfig bond0 down
-# echo 6 > /sys/class/net/bond0/bonding/mode
- - or -
-# echo balance-alb > /sys/class/net/bond0/bonding/mode
- NOTE: The bond interface must be down before the mode can be
-changed.
-
-To enable MII monitoring on bond0 with a 1 second interval:
-# echo 1000 > /sys/class/net/bond0/bonding/miimon
- NOTE: If ARP monitoring is enabled, it will disabled when MII
-monitoring is enabled, and vice-versa.
-
-To add ARP targets:
-# echo +192.168.0.100 > /sys/class/net/bond0/bonding/arp_ip_target
-# echo +192.168.0.101 > /sys/class/net/bond0/bonding/arp_ip_target
- NOTE: up to 10 target addresses may be specified.
-
-To remove an ARP target:
-# echo -192.168.0.100 > /sys/class/net/bond0/bonding/arp_ip_target
-
-Example Configuration
----------------------
- We begin with the same example that is shown in section 3.3,
-executed with sysfs, and without using ifenslave.
-
- To make a simple bond of two e100 devices (presumed to be eth0
-and eth1), and have it persist across reboots, edit the appropriate
-file (/etc/init.d/boot.local or /etc/rc.d/rc.local), and add the
-following:
-
-modprobe bonding
-modprobe e100
-echo balance-alb > /sys/class/net/bond0/bonding/mode
-ifconfig bond0 192.168.1.1 netmask 255.255.255.0 up
-echo 100 > /sys/class/net/bond0/bonding/miimon
-echo +eth0 > /sys/class/net/bond0/bonding/slaves
-echo +eth1 > /sys/class/net/bond0/bonding/slaves
-
- To add a second bond, with two e1000 interfaces in
-active-backup mode, using ARP monitoring, add the following lines to
-your init script:
-
-modprobe e1000
-echo +bond1 > /sys/class/net/bonding_masters
-echo active-backup > /sys/class/net/bond1/bonding/mode
-ifconfig bond1 192.168.2.1 netmask 255.255.255.0 up
-echo +192.168.2.100 /sys/class/net/bond1/bonding/arp_ip_target
-echo 2000 > /sys/class/net/bond1/bonding/arp_interval
-echo +eth2 > /sys/class/net/bond1/bonding/slaves
-echo +eth3 > /sys/class/net/bond1/bonding/slaves
-