Failover driver

modulename: net_failover.ko

configname: CONFIG_NET_FAILOVER

Linux Kernel Configuration
└─>Device Drivers
└─>Network device support
└─>Failover driver
In linux kernel since version 4.2 (release Date: 2015-08-30)  
This provides an automated failover mechanism via APIs to create
and destroy a failover master netdev and manages a primary and
standby slave netdevs that get registered via the generic failover
infrastructure. This can be used by paravirtual drivers to enable
an alternate low latency datapath. It also enables live migration of
a VM with direct attached VF by failing over to the paravirtual
datapath when the VF is unplugged.

source code: