Bond operating modes

Bonds combine two or more physical network interfaces into one virtual network interface. The use of bonds can improve the network’s fault tolerance and increase its throughput capacity.

Bonds operate in one of the following modes:

Mode	Name	Work logic	Purpose	Comments
balance-rr	Round-robin policy	Packets are sent from each interface in turn, starting with the first. If one of the interfaces fails, no packets are sent from it.	Load balancing Fault tolerance	May require additional configuration on the switch — static port trunking.
active-backup	Active-standby policy	One interface works in the active mode, the others – in the standby mode. If the active interface fails, control is transferred to one of the standby interfaces.	Fault tolerance	Does not require mode support on the switch.
balance-xor	XOR policy	Packet transmission is distributed between interfaces according to a special formula. The interface through which the packet will be transmitted is calculated through the logical XOR function for the source and destination MAC addresses. In this way, each interface transmits packets to specific recipients.	Load balancing Fault tolerance	May require additional configuration on the switch — static port trunking.
broadcast	Broadcast policy	The packet is transmitted through all interfaces at once.	Fault tolerance	May require additional configuration on the switch — static port trunking.
802.3ad	IEEE 802.3ad channel aggregation.	Aggregated groups of interfaces with the same speed and duplex are created. By default, the interface for transmitting a packet is defined as in balance-xor mode.	Increase of throughput capacity	Requires ethtool support in the interface driver. Requires additional configuration and support for IEEE 802.3ad on the switch.
balance-tlb	Adaptive transmission load balancing policy	Incoming traffic is received only by the active interface, outgoing traffic is distributed depending on the current load of each interface. If an active interface fails, its MAC address is transferred to another interface.	Fault tolerance Load balancing of outgoing traffic	Requires ethtool support in the interface driver. Does not require mode support on the switch.
balance-alb	Adaptive load balancing policy	Incoming traffic is distributed between interfaces as in balance-rr mode. Outgoing traffic is distributed depending on the current load of each interface.	Load balancing	Requires ethtool support in the interface driver. Does not require mode support on the switch. Requires the ability to change device MAC addresses.

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