On 30/07/2023 14:28, Darren Ankney wrote:
I have not tested this, but you could use the 'v6-only-preferred' setting in the subnet (see: https://kea.readthedocs.io/en/kea-2.4.0/arm/dhcp4-srv.html#ipv6-only-preferred-networks).
As the config I included in my original mail shows, I'm already using that option. Yes it works. But I still end up *offering* clients an IPv4 address from the pool, even those which request the v6-only-preferred option and will actually not request the offered address; and RFC 8925 says the server should set yiaddr 0.0.0.0 in this situation.
If I'm understanding what you are saying ... DON'T allocate v4 to clients who DON'T send v6 only option? Won't that result in a bunch of clients with no IP at all?
No, because those clients will still be able to get an IPv6 address (via either SLAAC or DHCPv6, depending on what I set up on the network)
Kea does not appear to offer native support for RFC 2563. I must not be understanding what you are saying. You also want the clients that didn't receive any ip address (v4 or v6) to not auto-configure a 169.254 address?
Correct. Clients which don't understand RFC 8925 will still try to obtain an IPv4 address. However, if they support RFC 2563 then I can detect this, and use this option to control whether or not they assign a link-local IPv4 address. Again: if I'm not offering them a real IPv4 address, then the RFC says the yiaddr should be 0.0.0.0.
Clients which don't implement either RFC 2563 or RFC 8925, I don't want to respond to. If they choose to assign a link-local IPv4 address, that's up to them.
Regards, Brian. -- ISC funds the development of this software with paid support subscriptions. Contact us at https://www.isc.org/contact/ for more information. To unsubscribe visit https://lists.isc.org/mailman/listinfo/kea-users. Kea-users mailing list Kea-users@lists.isc.org https://lists.isc.org/mailman/listinfo/kea-users
