It's time to switch to rad(8); tested by many.

Remove rtadvd(8) from rc(8).
OK deraadt, phessler

src/etc/rc

@@ -1,4 +1,4 @@
-#	$OpenBSD: rc,v 1.528 2018/07/12 08:20:36 florian Exp $
+#	$OpenBSD: rc,v 1.529 2018/07/23 11:54:49 florian Exp $
 
 # System startup script run by init on autoboot or after single-user.
 # Output and error are redirected to console by init, and the console is the
@@ -581,7 +581,7 @@ run_upgrade_script sysmerge
 
 echo -n 'starting network daemons:'
 start_daemon ldomd sshd switchd snmpd ldpd ripd ospfd ospf6d bgpd ifstated
-start_daemon relayd dhcpd dhcrelay mrouted dvmrpd radiusd eigrpd route6d rtadvd
+start_daemon relayd dhcpd dhcrelay mrouted dvmrpd radiusd eigrpd route6d
 start_daemon rad hostapd lpd smtpd slowcgi httpd ftpd
 start_daemon ftpproxy ftpproxy6 tftpd tftpproxy identd inetd rarpd bootparamd
 start_daemon rbootd mopd vmd spamd spamlogd sndiod

src/etc/rc.conf

@@ -1,4 +1,4 @@
-#	$OpenBSD: rc.conf,v 1.217 2018/07/12 08:20:36 florian Exp $
+#	$OpenBSD: rc.conf,v 1.218 2018/07/23 11:54:49 florian Exp $
 
 # DO NOT EDIT THIS FILE!!
 #
@@ -54,8 +54,6 @@ relayd_flags=NO
 rebound_flags=NO
 ripd_flags=NO
 route6d_flags=NO	# be sure to set net.inet6.ip6.forwarding=1
-rtadvd_flags=NO		# for normal use: list of interfaces
-			# be sure to set net.inet6.ip6.forwarding=1
 sasyncd_flags=NO
 sensorsd_flags=NO
 slaacd_flags=