Link Aggregation (LAG)

The Linux bonding driver provides a method for aggregating multiple network interfaces into a single logical "bonded" interface. The current version of the bonding driver is available in the “drivers/net/bonding” subdirectory of the most recent kernel source. It is recommended to configure bonding via iproute2 (netlink) or sysfs. The "ifenslave" control utility is no longer supported.

Bonding Method

• To create a LAG bond device:
  $ ip link add name bond1 type bond mode 802.3ad
$ ip link add name bond1 type bond mode balance-xor miimon 1000
$ ip link add name bond1 type bond mode active-backup miimon 1000
  NOTE: These options are supported: 802.3ad (LACP), balance-xor, active-backup
  NOTE: providing MII polling interval with miimon is mandatory for balance-xor, and active-backup to work properly.
• To remove a LAG bond device:
  $ ip link del dev bond1
• To set operational mode:
  In general, the bond device can support different operational modes. The operational mode can be set using following command:
  $ ip link set dev bond1 type bond mode 802.3ad
• To add a member to a LAG:
  $ ip link set dev sw1p1 master bond1
• To remove a member from a LAG:
  $ ip link set dev sw1p1 nomaster
• To show LAG information:
  $ cat /proc/net/bonding/bond1

Enabling a Member in a LAG

To enable a specific member in a LAG, the appropriate net_dev interface should be enabled:
$ ip link set sw1p1 up

Disabling a Member in a LAG

In order to disable a specific member in a LAG, enable the appropriate net_dev interface:
$ ip link set sw1p1 down

Administrative Status of a LAG Interface

In order to bring up/down the LAG interface, run the following command:
$ ip link set [bond1] [up|down]

MAC Address Setting on a LAG Interface

The MAC address of LAG interface is the address of first member of this LAG.
In order to change it, run the following command:
$ ip link set [bond1] address [XX:XX:XX:XX:XX:XX]

MTU Setting on a LAG Interface

In order to set MTU on the LAG interface, run the following command:
$ ip link set [bond1] mtu [XX]

Speed and Auto-Negotiation Setting on a LAG Interface

The speed and auto-negotiation setting are not supported for bond interface.
In order to configure the speed or auto-negotiation, complete the following actions:

1. Disable LAG interface (ip link set [bond1] down)
2. Disable LAG members (ip link set [sw1pX] down)
3. Configure speed or auto-negotiation for every LAG member
4. Enable LAG members (ip link set [sw1pX] up)
5. Enable LAG interface (ip link set [bond1] up)

Adding a LAG Interface to a Bridge

To add a LAG interface to a bridge, run the following command:
$ ip link set [bond1] master br0

Adding a LAG Interface to a VLAN

To configure a VLAN on the LAG interface, run the following command:
$ bridge vlan add vid [XX] pvid dev [bond1]

Setting Bridge LAG Interface Attributes

To configure bridge port attributes for a LAG, run the following command:
$ bridge link set dev [bond1] learning off flood off

Add an IP Address to a LAG

To configure an IP address for a LAG, run the following command:
$ ip addr add [192.168.1.2/24] dev [bond1]

VRF

To set a bond interface as a part of virtual router, run the following command:
$ ip link set dev [bond1] master [vrf_name]

NOTES

• Up to 62 LAGs are supported.
• Up to 8 port members per LAG.
• Only the bond configuration mechanism is supported.
• These options are supported: 802.3ad (LACP), balance-xor,active-backup.
• The switchport sw1pX must have admin down state in order to add it to LAG (Linux limitation)
• Binding a port to the LAG device that already has an upper device is not supported.
• Changing speed/auto-negotiation on a LAG interface is not supported. The speed should be manually changed on all members. (Linux limitation)
• LAG ACL is not supported.
• Changing the MTU of a port which is part of LAG affects (rewrites) the LAG MTU setting for this port.