Link Aggregation

Network bonding joins two or more network interfaces together. Depending on the configuration, you can increase bandwidth, throughput, performance and redundancy.

Linux

There is a bonding kernel module which can bond multiple network interfaces into a virtual bonded network interface. There are a few modes that are supported:

Type	Description
mode=0, mode=balance-rr	Round Robin policy and is the default mode.
mode=1, mode=active-backup	Only one slave is active at one time. All slave interfaces will share the same MAC address.
mode=3, mode=broadcast	Everything is transmitted on all slave interfaces
mode=4, mode=802.3ad	Dynamic Link Aggregation mode on a switch that supports IEEE 802.3ad dynamic link.
mode=5, mode=balance-tlb	Adaptive transmit load balancing. Outgoing traffic is distributed based on load on each slave.
mode=6, mode=balance-alb	Adaptive load balancing.

You can see the current bonding status by reading /proc/net/bonding/bond0:

# cat /proc/net/bonding/bond0
Ethernet Channel Bonding Driver: v3.7.1 (April 27, 2011)
 
Bonding Mode: fault-tolerance (active-backup) (fail_over_mac active)
Primary Slave: None
Currently Active Slave: ib2
MII Status: up
MII Polling Interval (ms): 100
Up Delay (ms): 0
Down Delay (ms): 0
 
Slave Interface: ib0
MII Status: up
Speed: 56000 Mbps
Duplex: full
Link Failure Count: 2
Permanent HW addr: a0:00:00:2a:fe:80
Slave queue ID: 0
 
Slave Interface: ib1
MII Status: up
Speed: 56000 Mbps
Duplex: full
Link Failure Count: 1
Permanent HW addr: a0:00:00:2c:fe:80
Slave queue ID: 0
 
Slave Interface: ib2
MII Status: up
Speed: 56000 Mbps
Duplex: full
Link Failure Count: 0
Permanent HW addr: a0:00:00:2a:fe:80
Slave queue ID: 0
 
Slave Interface: ib3
MII Status: up
Speed: 56000 Mbps
Duplex: full
Link Failure Count: 0
Permanent HW addr: a0:00:00:2c:fe:80
Slave queue ID: 0

See Also

• https://www.interserver.net/tips/kb/network-bonding-types-network-bonding/
• https://wiki.debian.org/Bonding