Comment 10 for bug 1447715

This is fixed in debian ifupdown 0.8.11 by this patch:
--- ifupdown-0.8.10/wait-for-ll6.sh 2015-12-01 16:50:26.000000000 -0500
+++ ifupdown-0.8.11/wait-for-ll6.sh 2016-04-20 08:57:37.000000000 -0400
@@ -4,7 +4,7 @@
 delay=${IF_LL_INTERVAL:-0.1}

 for attempt in $(seq 1 $attempts); do
- lladdress=$(ip -6 -o a s dev "$IFACE" scope link)
+ lladdress=$(ip -6 -o a s dev "$IFACE" scope link -tentative)
  if [ -n "$lladdress" ]; then
   attempt=0
   break