// Module included in the following assemblies:
//
// * networking/advanced_networking/network-bonding-considerations.adoc

:_mod-docs-content-type: CONCEPT
[id="nw-kernel-bonding_{context}"]
= Kernel bonding

[role="_abstract"]
You can use kernel bonding, which is a built-in Linux kernel function where link aggregation can exist among many Ethernet interfaces, to create a single logical physical interface. Kernel bonding allows multiple network interfaces to be combined into a single logical interface, which can enhance network performance by increasing bandwidth and providing redundancy in case of a link failure. 

Kernel bonding is the default mode if no bond interfaces depend on OVS bonds. This bonding type does not give the same level of customization as supported OVS bonding.

For `kernel-bonding` mode, the bond interfaces exist outside, which means they are not in the data path, of the bridge interface. Network traffic in this mode is not sent or received on the bond interface port but instead requires additional bridging capabilities for MAC address assignment at the kernel level. 

If you enabled `kernel-bonding` mode on network controller interfaces (NICs) for your nodes, you must specify a Media Access Control (MAC) address failover. This configuration prevents node communication issues with the bond interfaces, such as `eno1f0` and `eno2f0`.

Red{nbsp}Hat supports only the following value for the `fail_over_mac` parameter:

* `0`: Specifies the `none` value, which disables MAC address failover so that all interfaces receive the same MAC address as the bond interface. This is the default value.

Red{nbsp}Hat does not support the following values for the `fail_over_mac` parameter:

* `1`: Specifies the `active` value and sets the MAC address of the primary bond interface to always remain the same as active interfaces. If during a failover, the MAC address of an interface changes, the MAC address of the bond interface changes to match the new MAC address of the interface.

* `2`: Specifies the `follow` value so that during a failover, an active interface gets the MAC address of the bond interface and a formerly active interface receives the MAC address of the newly active interface.

