Prefix delegation to sub nets

[Doug Hardie]

I have been working my way through the RFCs and it appears HNCP might be the solution.  However, both of those implementations require the prefix from the ISP be configured by hand.  That is not viable in situations where a dynamic IP address is provided.  I suspect that HNCP and DHCP6 will need to be integrated for that.  

-- Doug

> On 28 June 2021, at 03:00, Chriztoffer Hansen <ch at ntrv.dk> wrote:
> 
> You could try https://github.com/jech/shncpd or
> https://github.com/sbyx/hnetd/, though the last update to those
> repositories was 2017-2018...
> 
> 
> On Mon, 28 Jun 2021 at 11:10, Brian Carpenter
> <brian.e.carpenter at gmail.com> wrote:
>> 
>> Is HNCP available for the various Linux distros?
>> If not, it has to be PD, I think.
>> 
>> Regards,
>>    Brian Carpenter
>>    (via tiny screen & keyboard)
>> 
>> On Mon, 28 Jun 2021, 20:51 Ole Troan, <otroan at employees.org> wrote:
>>> 
>>> 
>>> 
>>>> On 27 Jun 2021, at 23:07, Brian E Carpenter <brian.e.carpenter at gmail.com> wrote:
>>>> 
>>>> That doesn't work. B needs to get its own /64 prefix(es) from A via DHCPv6-PD (https://www.rfc-editor.org/info/rfc8415). That's what DHCPv6-PD is for. So A will indeed need to be a DHCPv6 server on its downstream interfaces.
>>> 
>>> To the extent it matters, it’s not what DHCP PD was designed for.
>>> 
>>> HNCP does internal prefix assignment in a network.
>>> 
>>> Now, if you were to use DHCP PD for this, I would recommend a single PD server in the network (on A).  DHCP PD clients on all internal routers. Either DHCP relays or more simply each internal router PD client configured with the address of the PD server directly. Then an IGP to advertise prefixes.
>>> 
>>> The PD clients should request individual /64s for each of their downstream interfaces.
>>> 
>>> This scheme does not work great in networks with loops or multiple routers on a link. If using DHCP relays you manually have to make a spanning tree.
>>> And you risk links being assigned multiple prefixes.
>>> 
>>> HNCP solves all of this.
>>> 
>>> Cheers
>>> Ole
> 
> 
> 
> -- 
> Chriztoffer
>