IPv6: Segment Routing Header encapsulation support

configname: CONFIG_IPV6_SEG6_LWTUNNEL

Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>The IPv6 protocol
└─>IPv6: Segment Routing Header encapsulation support
In linux kernel since version 4.1 (release Date: 2015-06-21)  
Support for encapsulation of packets within an outer IPv6
header and a Segment Routing Header using the lightweight
tunnels mechanism.

If unsure, say N.