What network bonding is: joining links, methods and names

Bonding is a technique that turns a slow or vulnerable network into a faster and more reliable one. It joins several network links into one. Let us explain how it works, what methods exist and what the same thing is called across different vendors, because there are many names.

What bonding is

Bonding (sometimes also teaming or link aggregation) is joining two or more network links into one logical connection. The goal is either higher throughput, or a backup during a failure, or both at once. This relates to the article on a computer with two network cards.

Imagine it as joining two lanes into one wider road: more cars pass through, and when one lane closes, traffic keeps flowing.

What bonding brings

• Higher throughput. More links means greater total transfer, especially with several simultaneous connections.
• Redundancy. When one link or cable fails, traffic continues over the rest.
• Load balancing across the links.

The main bonding methods

There are several methods, differing in whether switch support is needed and what exactly they do. The most common:

• Active-backup. Only one link works, the other waits and replaces it on failure. The main goal is backup. It requires no special switch support.
• LACP (802.3ad), dynamic aggregation. The links are joined into one bundle and the switch and computer agree on splitting the traffic. It gives both speed and backup, but the switch must support and be configured for it.
• Balance (round-robin and similar). Traffic is spread across links by a rule. It increases throughput, with or without switch support depending on the method.
• Adaptive methods that distribute load according to current traffic.

An important rule: two links do not mean double speed for a single download. Bonding spreads multiple connections, not one stream. It shows the most where there are many simultaneous transfers, for example on a server.

The same thing under different names

This is a common source of confusion. The same principle has a different name with every vendor:

So when you read EtherChannel in one guide and bonding in another, it is often the same thing, just in different words.

Where bonding is used

• Servers and NAS with many simultaneous users.
• Links between switches (uplinks), where one link is not enough.
• Critical connections that must not drop.
• Virtualization host machines, where many systems run at once, related to the article on what a hypervisor is.

What to keep in mind before deploying

• Check the switch support for the chosen method (especially LACP).
• The same configuration on both sides. A mismatch causes problems.
• Test a failure of one link to see whether the backup really works.

Want a faster and more reliable connection on a server or network via bonding? Get in touch, we will design the method and wiring and set it all up and test it.