extern bool ip6_link_is_enabled (u32 sw_if_index);
extern int ip6_link_disable (u32 sw_if_index);
extern const ip6_address_t *ip6_get_link_local_address (u32 sw_if_index);
extern bool ip6_link_is_enabled (u32 sw_if_index);
extern int ip6_link_disable (u32 sw_if_index);
extern const ip6_address_t *ip6_get_link_local_address (u32 sw_if_index);