IP: FOU encapsulation of IP tunnels

configname: CONFIG_NET_FOU_IP_TUNNELS

Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>IP: FOU encapsulation of IP tunnels
In linux kernel since version 3.19 (release Date: 2015-02-08)  
Allow configuration of FOU or GUE encapsulation for IP tunnels.
When this option is enabled IP tunnels can be configured to use
FOU or GUE encapsulation.