add netcup ipv6 fbsd post

ponderings/my-battles-with-netcup-ipv6-on-freebsd/index.html

@@ -146,14 +146,14 @@ they have provided, but they also sent one via email, so I'll just use that for
 Reboot the VPS again... oh, it's back. Great. Wait a few minutes, it goes again. Reboot, back, wait, gone. And so on.</p>
 <h3 id="tests-and-research">Tests and Research</h3>
 <p>Obviously the first thing I'm thinking is firewall. So I disable <code>pf</code> and reboot and wait again - no difference, IPv6 just stops working after a few minutes.</p>
-<p>In my fairly inexperienced IPv6 knowledge (it's not big in the UK... yet), using <code>fe80::1</code> as a gateway feels weird, so I try a <code>traceroute6 anyaddress.com</code> to see what the first hope on the route is (it must be my actual gateway, right?) and pop that address into my <code>ipv6_defaultrouter=</code> config in <code>rc.conf</code>.<br />
+<p>In my fairly inexperienced IPv6 knowledge (it's not big in the UK... yet), using <code>fe80::1</code> as a gateway feels weird, so I try a <code>traceroute6 anyaddress.com</code> to see what the first hop on the route is (it must be my actual gateway, right?) and pop that address into my <code>ipv6_defaultrouter=</code> config in <code>rc.conf</code>.<br />
 Reboot... no joy, no IPv6 connectivity at all. OK, I set that back.</p>
 <p>I browse the netcup forums a bit, find a handful of posts of people experiencing the same issue. Some refer to people leasing an additional IPv6 lease from Netcup and using that instead which allegedly works for them. I did this, it did not work for me - the IPv6 worked, for about 10 minutes again, then dropped off as before.<br />
 FreeBSD forums is the same sort of thing, articles from a few years ago.</p>
 <p>Both forums seem to have posts saying the issue lies in the fact the IPv6 address and [actual] gateway exist in different subnets.
 My simple understanding of this is: the gateway may have address <code>2a03:4000:AAAA::2</code> which is in a /48 subnet, and my VPS may have IPv6 address <code>2a03:4000:AAAA:BBBB::1234</code> which is a /64 subnet. Because they do not exist on the same subnet, <em>something</em> happens at some point to stop them being able to communicate. I believe this "<em>something</em>" is to do with Netcup's switching (rather than routing).</p>
 <p>Of the people experiencing this, some have had the IPv6 Connectivity come back and drop off again on its own. I haven't experienced this, but perhaps I'm just impatient.</p>
-<p>So, <a href="https://forums.freebsd.org/threads/netcup-ipv6-intermittant.96489/">I write a post on the FreeBSD forums</a> with a bit of information of things I've tried asking for help. I like this to a <a href="https://notnull.space/@paul/statuses/01JHZK2YK2JXJ49NW1V1CV2Y1F">Fediverse post</a> and wait for responses. It doesn't take long.</p>
+<p>So, <a href="https://forums.freebsd.org/threads/netcup-ipv6-intermittant.96489/">I write a post on the FreeBSD forums</a> with a bit of information of things I've tried asking for help. I link this to a <a href="https://notnull.space/@paul/statuses/01JHZK2YK2JXJ49NW1V1CV2Y1F">Fediverse post</a> and wait for responses. It doesn't take long.</p>
 <h3 id="switching-the-subnet">Switching the subnet</h3>
 <p><code>@fab</code> responds with the idea of using a /48 prefix instead of /64.
 Given what I have learned up to this point, this could make sense - the gateway is in a /48 of the same first 48 bits of my /64 subnet (<code>2a03:4000:AAAA</code>)
@@ -237,6 +237,19 @@ Outgoing <code>ping6</code>s still seem OK though... let's switch that default r
 In the meantime, I welcome any comments about things that I could do further to help, or, indeed, comments for reasons why I should not have done any of the above. I'm familiar with networks, but with IPv6 being ignored in the UK my knowledge of it is a little lacking.</p>
 <p>If you want to send any comments, please do so either on <a href="https://forums.freebsd.org/threads/netcup-ipv6-intermittant.96489/#post-686757">this FreeBSD Forum thread</a> or on <a href="https://notnull.space/@paul/statuses/01JHZK2YK2JXJ49NW1V1CV2Y1F">this Fediverse thread</a>.</p>
 <p>EDIT: I guess I should have found <a href="https://forums.freebsd.org/threads/how-to-set-ipv6-gateway.68568/post-408655">this post on the FreeBSD forums</a> earlier, which alludes to the same thing.</p>
+<h3 id="updates">Updates</h3>
+<p>After a while of the above, <code>ndp -a</code> is showing something like the below:</p>
+<pre data-lang="sh" style="background-color:#212121;color:#eeffff;" class="language-sh "><code class="language-sh" data-lang="sh"><span style="color:#82aaff;">Neighbor                             Linklayer Address  Netif Expire    S Flags
+</span><span style="color:#82aaff;">fe80::1</span><span style="color:#89ddff;">%</span><span>vtnet0                       </span><span style="color:#89ddff;">**</span><span style="color:#82aaff;">:</span><span style="color:#89ddff;">**</span><span style="color:#82aaff;">:</span><span style="color:#89ddff;">**</span><span style="color:#82aaff;">:</span><span style="color:#89ddff;">**</span><span style="color:#82aaff;">:</span><span style="color:#89ddff;">**</span><span style="color:#82aaff;">:</span><span style="color:#89ddff;">**</span><span style="color:#82aaff;"> vtnet0 20h12m4s  S R
+</span><span style="color:#82aaff;">2a03:4000:AAAA::2                    </span><span style="color:#89ddff;">**</span><span style="color:#82aaff;">:</span><span style="color:#89ddff;">**</span><span style="color:#82aaff;">:</span><span style="color:#89ddff;">**</span><span style="color:#82aaff;">:</span><span style="color:#89ddff;">**</span><span style="color:#82aaff;">:</span><span style="color:#89ddff;">**</span><span style="color:#82aaff;">:</span><span style="color:#89ddff;">**</span><span style="color:#82aaff;"> vtnet0 23h59m52s S R
+</span><span style="color:#82aaff;">2a03:4000:AAAA::3                    </span><span style="color:#89ddff;">**</span><span style="color:#82aaff;">:</span><span style="color:#89ddff;">**</span><span style="color:#82aaff;">:</span><span style="color:#89ddff;">**</span><span style="color:#82aaff;">:</span><span style="color:#89ddff;">**</span><span style="color:#82aaff;">:</span><span style="color:#89ddff;">**</span><span style="color:#82aaff;">:</span><span style="color:#89ddff;">**</span><span style="color:#82aaff;"> vtnet0 12s       R R
+</span></code></pre>
+<p>So perhaps both gateways are in use? That's good I guess.<br />
+I've seen, a few times but rarely, my remote <code>ping6</code>s to my Netcup VPS become unreachable
+but after a shortwhile it starts working again without any interactions. I'm <em>hoping</em> this
+"self-repair" is something to do with having both routes set up,
+meaning I don't have to worry about it any more - I just need to set the second gateway
+up in my <code>rc.conf</code> as well.</p>
 
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