The kernel sets IN6_IFF_AUTOCONF for autoconf addresses, also make

slaacd(8) do that. At least you can identify them in ifconfig output.
Difference pointed out by & OK naddy

diff --git a/usr.sbin/slaacd/slaacd.c b/usr.sbin/slaacd/slaacd.c
index f1f6388..79575b3 100644 (file)
--- a/usr.sbin/slaacd/slaacd.c
+++ b/usr.sbin/slaacd/slaacd.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: slaacd.c,v 1.19 2017/05/29 08:59:42 florian Exp $     */
+/*     $OpenBSD: slaacd.c,v 1.20 2017/05/29 20:31:31 florian Exp $     */
 
 /*
  * Copyright (c) 2017 Florian Obser <florian@openbsd.org>
@@ -665,6 +665,9 @@ configure_interface(struct imsg_configure_address *address)
 
        in6_addreq.ifra_lifetime.ia6t_preferred = t + address->pltime;
        in6_addreq.ifra_lifetime.ia6t_pltime = address->pltime;
+
+       in6_addreq.ifra_flags |= IN6_IFF_AUTOCONF;
+
        if (address->privacy)
                in6_addreq.ifra_flags |= IN6_IFF_PRIVACY;