extern const NetDevVTable vti_vtable;
extern const NetDevVTable gre_vtable;
extern const NetDevVTable gretap_vtable;
+extern const NetDevVTable ip6gre_vtable;
+extern const NetDevVTable ip6gretap_vtable;
extern const NetDevVTable ip6tnl_vtable;
const char *ip6tnl_mode_to_string(Ip6TnlMode d) _const_;