Ethernet Bonding

Giriş

Bazı bonding modları şöyle

broadcast

balance-alb

balance-xor

balance-rr

broadcast

Açıklaması şöyle

broadcast mode largely exists just to provide a bonding mode that can handle the loss of a bound interface without any disruption whatsoever (active-backup mode, which provides similar fault-tolerance, will show a small latency spike if the active bound interface goes down because it has to reroute traffic and force updates of external ARP caches). It’s realistically only usable on layer 2 point-to-point links between systems that are both using the bonding driver (possibly even the same mode), and gives you no performance benefits.

balance-rr

Açıklaması şöyle

balance-rr mode is instead designed to have minimal overhead, irrespective of whatever other constraints exist, and it actually does translate to evenly balancing the load across all bound interfaces. The problem is that if there is more than one hop below layer 3, this mode cannot provide packet ordering guarantees, which in turn causes all kinds of issues with congestion control algorithms, functionally capping effective bandwidth. It is also, in practice, only usable on layer 2 point-to-point links between systems that are both using the bonding driver.

Bir soru ve cevap şöyle

Q : Linux is capable of bonding NICs together. The interesting policy for this is Round-robin, which alternates outgoing packets between each NIC.

A : For the single flow, any bandwidth gain in the direction from the switch to the client is highly unlikely.

...

So any bandwidth gain for single flow is HIGHLY unlikely. You may see some gain using multiple flows, depending on hashing policy the switch uses and the server configured (see xmit_hash_policy for what's available, you will need policy policy which includes L4 information to gain anything between two specific hosts).

balance-alb

Açıklaması şöyle

Assuming your switch plays nice with it, you probably want balance-alb mode, as it will give you the best overall link utilization spread across the links. However, some network hardware does not like how that mode handles receive load balancing, in which case you almost certainly instead want 802.3ad mode (if your switch supports it, and all the bound interfaces are connected to the same switch) or balance-xor (does the same thing, but the switch has to infer what’s going on, so does not work as well in all cases).