title: ipv6 neigh entries getting failed
body: <p>I have bunch of ipv6 neigh entries which are failed:</p>
  
  <pre><code>6000::2828:2802 dev eth2 lladdr 00:1f:a0:02:0e:b2 STALE
  7000::1e1e:1e01 dev eth1  FAILED
  8000::1e1e:1e01 dev eth1  FAILED
  4000::1414:149e dev eth2 lladdr 00:03:00:04:00:09 PERMANENT
  5000::1e1e:1e01 dev eth1  FAILED
  3000::a0a:a3a dev eth1 lladdr 00:03:00:03:00:09 PERMANENT
  </code></pre>
  
  <p>Now, When I use flush to remove these entries, it says nothing to flush. Do you guys know how to flush or remove these entries, If I delete the entry, it goes in the failed state. Can I change the time for these values, so it automatically gets removed in say 10 seconds.</p>