<h4>Description</h4>
<p>When using the GNRC_IPV6_NIB_CONF_SLAAC option a network connection to a riot node doesn't recover to a working state after a router reboot.<br>
Actually this doesn't seem to be a real bug in riot but more an iterop problem between riot and linux.<br>
After offline discussion with <a class="user-mention" data-hovercard-type="user" data-hovercard-url="/hovercards?user_id=10532675" data-octo-click="hovercard-link-click" data-octo-dimensions="link_type:self" href="https://github.com/smlng">@smlng</a> I'm adding it here mostly for documentation and discussion with more people.<br>
Since linux-wpan is basically the goto-solution when setting up a linux based border router it would be nice if we could somehow avoid/improve/workaround this problem, any opinions on that?</p>

<h4>Steps to reproduce the issue</h4>

<p>Requirements: a riot board with radio and a border router (e.g. raspi) with ssh access.<br>
Use examples/gnrc_networking replace <code>USEMODULE += gnrc_ipv6_router_default</code> with <code>USEMODULE += gnrc_ipv6_default</code>.</p>
<p>Compile with <code>CFLAGS=-DGNRC_IPV6_NIB_CONF_SLAAC BOARD=whatever make all flash term</code></p>
<p>After that reboot the riot board and observe that everything looks ok with <code>ip neigh show dev lowpan0</code> on your border router.<br>
Then perform a router reboot (or run <code>sudo ip neigh flush dev lowpan0</code> on it to get the same effect) and then try to ping the global address of the board -> this will fail with destination unreachable.</p>
<p>Only way to get it back to a working state is to reboot the riot board.</p>
<p>This problem does not appear if either:<br>
a) NOT using <code>CFLAGS=-DGNRC_IPV6_NIB_CONF_SLAAC</code><br>
b) using <code>USEMODULE += gnrc_ipv6_router_default</code></p>
<p>The reason seems to be that the router is sending the Neighbor Solicitation to the solicited node multicast address but riot is not handling it in this specific configuration.</p>
<h4>Expected results</h4>

<p>Riot node is reachable via it's global address after a router reboot.</p>
<h4>Actual results</h4>

<p>Riot node is unreachable via it's global address after a router reboot.</p>
<h4>Versions</h4>

<p>current master<br>
Related: <a class="issue-link js-issue-link" data-error-text="Failed to load issue title" data-id="119191560" data-permission-text="Issue title is private" data-url="https://github.com/RIOT-OS/RIOT/issues/4353" data-hovercard-type="issue" data-hovercard-url="/RIOT-OS/RIOT/issues/4353/hovercard" href="https://github.com/RIOT-OS/RIOT/issues/4353">#4353</a></p>


<p style="font-size:small;-webkit-text-size-adjust:none;color:#666;">—<br />You are receiving this because you are subscribed to this thread.<br />Reply to this email directly, <a href="https://github.com/RIOT-OS/RIOT/issues/11038">view it on GitHub</a>, or <a href="https://github.com/notifications/unsubscribe-auth/AEn7YGxR4tt-YB_JVw_T5_sKVOMaYWjKks5vPXGqgaJpZM4bFjol">mute the thread</a>.<img src="https://github.com/notifications/beacon/AEn7YNHqftueuh2UQNe0E1-G4Mzr70-3ks5vPXGqgaJpZM4bFjol.gif" height="1" width="1" alt="" /></p>
<script type="application/json" data-scope="inboxmarkup">{"api_version":"1.0","publisher":{"api_key":"05dde50f1d1a384dd78767c55493e4bb","name":"GitHub"},"entity":{"external_key":"github/RIOT-OS/RIOT","title":"RIOT-OS/RIOT","subtitle":"GitHub repository","main_image_url":"https://github.githubassets.com/images/email/message_cards/header.png","avatar_image_url":"https://github.githubassets.com/images/email/message_cards/avatar.png","action":{"name":"Open in GitHub","url":"https://github.com/RIOT-OS/RIOT"}},"updates":{"snippets":[{"icon":"DESCRIPTION","message":"Neighbor Discovery not working after router reboot when using SLAAC (#11038)"}],"action":{"name":"View Issue","url":"https://github.com/RIOT-OS/RIOT/issues/11038"}}}</script>
<script type="application/ld+json">[
{
"@context": "http://schema.org",
"@type": "EmailMessage",
"potentialAction": {
"@type": "ViewAction",
"target": "https://github.com/RIOT-OS/RIOT/issues/11038",
"url": "https://github.com/RIOT-OS/RIOT/issues/11038",
"name": "View Issue"
},
"description": "View this Issue on GitHub",
"publisher": {
"@type": "Organization",
"name": "GitHub",
"url": "https://github.com"
}
}
]</script>