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<p>Hi Ron,</p>
<p>See inline:<br>
</p>
<div class="moz-cite-prefix">On 10/16/23 16:58, BCLUG wrote:<br>
</div>
<blockquote type="cite"
cite="mid:033787a1-309f-406e-aac8-5744514bf52a@bclug.ca">Craig
Miller wrote on 2023-10-16 16:48:
<br>
<br>
<blockquote type="cite">Typically a /64 is assigned to a VPS,
which will give you more IP addresses than you need.
<br>
</blockquote>
<br>
I requested "a couple, or a /64, what ever is easiest for you
guys", so I guess I got what I asked for.
<br>
</blockquote>
Yes, they gave you what was easiest for them. Still it looks like
IPv4 thinking to me.<br>
<blockquote type="cite"
cite="mid:033787a1-309f-406e-aac8-5744514bf52a@bclug.ca">
<br>
Having 5 * /112 should give me quite a few? Or just 5?
<br>
</blockquote>
Having 5 /112s means you will have 5 blocks of 65k addresses.
However, based on your example below, it looks like they just gave
you 5 addresses.<br>
<blockquote type="cite"
cite="mid:033787a1-309f-406e-aac8-5744514bf52a@bclug.ca">
<br>
When I run `ip addr show` I get:
<br>
<br>
inet6 2607:5300:203:b716::1:2/112 scope global
<br>
valid_lft forever preferred_lft forever
<br>
inet6 2607:5300:203:b716::1:3/112 scope global
<br>
valid_lft forever preferred_lft forever
<br>
inet6 2607:5300:203:b716::1:4/112 scope global
<br>
valid_lft forever preferred_lft forever
<br>
inet6 2607:5300:203:b716::1:5/112 scope global
<br>
valid_lft forever preferred_lft forever
<br>
inet6 2607:5300:203:b716::1:6/112 scope global
<br>
valid_lft forever preferred_lft forever
<br>
</blockquote>
However, what you listed is just 5 addresses in a single /112 block,
which may be all you need.<br>
<blockquote type="cite"
cite="mid:033787a1-309f-406e-aac8-5744514bf52a@bclug.ca">
<br>
Is that somehow equivalent to a /64, being contiguous?
<br>
</blockquote>
No, it is _far_ from the same. 5*2^16 is NOT equal to 2^64. Punch
that into a calculator and you will see the difference.<br>
<blockquote type="cite"
cite="mid:033787a1-309f-406e-aac8-5744514bf52a@bclug.ca">
<br>
Sorry, my brain isn't up to trying to calculate this myself at the
moment...
<br>
</blockquote>
<p>Even the IETF (the folks who create standards for the Internet
say less than /64 allocations is a bad idea</p>
<p><a class="moz-txt-link-freetext" href="https://www.rfc-editor.org/rfc/rfc7421#page-10">https://www.rfc-editor.org/rfc/rfc7421#page-10</a><br>
</p>
<blockquote type="cite"
cite="mid:033787a1-309f-406e-aac8-5744514bf52a@bclug.ca">
<br>
<br>
<blockquote type="cite">To answer your question, since there are
128 bits in an IPv6 address, 128-112=16 or 2^16 hosts in a /112
block.
<br>
</blockquote>
<br>
That's... 65536 addresses * 5 = 327680 addresses. "!"
<br>
<br>
<br>
And, how would I extract, say, 1 single IPv6 from
2607:5300:203:b716::1:6/112 -- what would that even look like?
<br>
<br>
I can ping the bare 2607:5300:203:b716::1:6 from another host,
which leads me to think it's a single IP, but I'm unclear.
<br>
</blockquote>
<p>Host addresses are made up of an address and a mask. You may want
to look at the last NetSIG preso for more info:</p>
<p><a class="moz-txt-link-freetext" href="http://www.makikiweb.com/netsig/2023_09_network_basics_addressing.html">http://www.makikiweb.com/netsig/2023_09_network_basics_addressing.html</a><br>
</p>
<p>But the real problem is that because you are using IPv6 in
compressed representation, the /112 doesn't make sense. Let me
expand it out for you, and it will make more sense. In your
example above: 2607:5300:203:b716::1:6/112 <br>
</p>
<pre>2607:5300:0203:b716:0000:0000:0001:0006/112
----------------------------------|
</pre>
<p>The mask takes up the first 112 bits (as indicated by the dashes
above)</p>
<p>The remaining 16 bits or '0006' is the host portion of the
address. Addresses should be dealt with on a nibble (or 4 bit)
basis in IPv6. Giving you 5 means they haven't divided your space
on nibble boundaries. Or perhaps they have only given you 5
addresses from a single /112. Again they are making it harder than
it needs to be, and they should just be handing out /64s (as
recommended by RFC 7421).</p>
<p>The beauty of IPv6, is you can do fun stuff with the address, and
give them "extra" meaning. For example, I run 2 servers, one is
dual stack, and the other is IPv6 only</p>
<pre>$ host <a class="moz-txt-link-abbreviated" href="http://www.makikiweb.com">www.makikiweb.com</a>
<a class="moz-txt-link-abbreviated" href="http://www.makikiweb.com">www.makikiweb.com</a> has address 46.235.225.189
<a class="moz-txt-link-abbreviated" href="http://www.makikiweb.com">www.makikiweb.com</a> has address 93.93.129.174
<a class="moz-txt-link-abbreviated" href="http://www.makikiweb.com">www.makikiweb.com</a> has IPv6 address 2a00:1098:8:78::f02
cvmiller@hala:~$ host <a class="moz-txt-link-abbreviated" href="http://www.makiki.ca">www.makiki.ca</a>
<a class="moz-txt-link-abbreviated" href="http://www.makiki.ca">www.makiki.ca</a> has IPv6 address 2a00:1098:8:78::f03
</pre>
<p>You can see that I have decided to use the digit "F" to indicate
that the request came into the server on IPv6 (e.g. ...:f02 and
...:f03). The V4 requests are via a proxy (the host is IPv6-only
with Mythic Beasts) and they come in as ...:002). So it is easy to
figure out if the traffic came in from the proxy or not.<br>
</p>
<p>I hope this helps,</p>
<p>Craig...<br>
</p>
<blockquote type="cite"
cite="mid:033787a1-309f-406e-aac8-5744514bf52a@bclug.ca">
<br>
<br>
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<br>
</blockquote>
<div class="moz-signature">-- <br>
IPv6 is the future, the future is here<br>
<a href="ipv6hawaii.org" class="moz-txt-link-freetext">ipv6hawaii.org</a></div>
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