IPv6: Router Preference (RFC 4191) support

configname: CONFIG_IPV6_ROUTER_PREF

Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>The IPv6 protocol
└─>IPv6: Router Preference (RFC 4191) support
In linux kernel since version 2.6.17 (release Date: 2006-06-17)  
Router Preference is an optional extension to the Router
Advertisement message which improves the ability of hosts
to pick an appropriate router, especially when the hosts
are placed in a multi-homed network.

If unsure, say N.