<div dir="ltr"><br><div class="gmail_extra"><div class="gmail_extra">Hi Tomek,</div><div class="gmail_extra"><span class="" style="white-space:pre"> </span>We are considering to support several CMTSs, so as you recommend us, we’re going to start assigning IA_NA as management address (side WAN) and IAPREFIX at the side LAN within the same subnet. Additionally, below I’m presenting another scenario where I found a problem and I would like to know your opinion:</div><div class="gmail_extra"><br></div><div class="gmail_extra">-<span class="" style="white-space:pre"> </span>Knowing that CMTS already supports route injection to update the prefixes assigned to eRouters according to RFC 4779 (Section 5.2.2.5 ), it could be possible to keep the prefix to a client which I need moving from one to other CMTS. In this case, if I have associated relay-agent, IA_NA pool and pd-pools altogether at the same subnet, it’s impossible to keep the same IAPREFIX because the subnet and the relay-agent changes when the client is moved to another CMTS. In this way, personally I think that I would be great, if Kea can support associate a same pd-pool with different subnets. </div><div class="gmail_extra"><br></div><div class="gmail_extra">What do you think?</div><div class="gmail_extra"><br></div><div class="gmail_extra">Regards,</div><div class="gmail_extra">Sebastian</div><div><br></div><div><div dir="ltr"><br></div></div>
<br><div class="gmail_quote">2014-09-24 15:08 GMT-03:00 Tomek Mrugalski <span dir="ltr"><<a href="mailto:tomasz@isc.org" target="_blank">tomasz@isc.org</a>></span>:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">On 23.09.2014 22:26, Sebastián Fritz wrote:<br>
> Hi Tomek,<br>
> Thank you for your help. I believe that, there is not<br>
> any problem in assign an IA_NA at the DOCSIS eRouter’s WAN side and a<br>
> different range prefix IAPREFIX at the DOCSIS eRouter’s LAN side. In<br>
> this way, I could have an smaller prefix to only assign IA_NA at the<br>
> WAN side and a bigger subnet to assign IAPREFIX at the LAN side.<br>
In a typical network, you would put both addresses (IA_NA + IAADDR) and<br>
prefixes (IA_PD + IAPREFIX) in the same subnet. That is important,<br>
because otherwise you can't aggregate routing configuration and for X<br>
clients you'd have to have X routing entries.<br>
<br>
Does that scale if you X goes into thousands clients? I honestly don't<br>
know. And I have very limited experience with cable modems.<br>
<br>
> Knowing that DOCSIS Spec suggests to do the<br>
> assignment (IA_NA) and DHCPv6 prefix delegation (IA_PD) in a single<br>
> DHCPv6 session. Do you plan to support it in the future?.<br>
Yes, we support responding to IA_NA and IA_PD in a single session already.<br>
<br>
> Below, there<br>
> is the references with this recommendation.<br>
><br>
> “CM-SP-eRouter-I13-140729” -( Section 8.3 - Obtain IPv6 address and<br>
> other configuration parameters),<br>
> (<a href="http://www.cablelabs.com/wp-content/uploads/specdocs/CM-SP-eRouter-I13-140729.pdf" target="_blank">http://www.cablelabs.com/wp-content/uploads/specdocs/CM-SP-eRouter-I13-140729.pdf</a>):<br>
><br>
><br>
> “...DHCPv6 address assignment (IA_NA) and DHCPv6 prefix delegation<br>
> (IA_PD) SHOULD be done as a single DHCPv6 session....”<br>
As stated above, we fully support that. I just read the whole section<br>
8.3. There is nothing in there that says that addresses and prefixes<br>
should belong to different subnets.<br>
<br>
What we don't support is the ability you are requesting: to send<br>
prefixes and addresses that belong to disjoint subnets.<br>
<br>
How many CTMSes you need to support? Here's something you may consider.<br>
If you need to provide arbitrary addresses and arbitrary prefixes, maybe<br>
subnet ::/0 would work for you?<br>
<br>
Hope that helps,<br>
Tomek<br>
<br>
p.s.<br>
Oh, and we don't support SOLMAXRT option mentioned in the docsis specs<br>
you linked. Fortunately, you can define custom option format and start<br>
sending this particular option. See section 6.2.7 of Kea ARM.<br>
<br>
</blockquote></div><br></div></div>