Linux bond mode 4 (802.3ad) - 2 switch - 4 NIC

Question

I know that you can use bonding mode 4 with 1 servers with 2 nic using 2 switch.

Bond 0 made of : Nic 1 port 1 -> switch A Nic 2 port 1 -> switch B

In this case I can loose a switch or a nic or a cable and still have my network working, if everything is working I will have link aggregation on the top of high availability .

My question is can you do the same but with 4 NIC to have more speed and still play it safe.

Bond 0 made of : Nic 1 port 1 -> switch A Nic 1 port 2 -> switch B Nic 2 port 1 -> switch A Nic 2 port 2 -> switch B

The switch will probably be CISCO.

Cheers

Answer 1

Bear in mind that with 802.3ad all of the links in your bond need to be connected to the same switch, unless the switch supports sharing the 802.3ad information with other switches through a stack/virtual switch type configuration.

That said, you could still achieve your configuration with 4 nics and two switches by just making a bond to each switch, for instance:

NIC1/port1 -> bond0 -> switch1
NIC1/port2 -> bond1 -> switch2
NIC2/port1 -> bond0 -> switch1
NIC2/port2 -> bond1 -> switch2

That way you get redundancy against a single NIC or switch failure, and increased bandwidth while the switches are working, but you'll have to manage the IP failover yourself.

Alternatively you could switch to bonding mode 6, drop the requirement for 802.3ad and run the configuration you suggested in your question.