Why used DHCPv6 when RA has RDNSS and DNSSL?

[ignatios at cs.uni-bonn.de]

On Tue, Mar 31, 2020 at 02:30:46AM +0200, Roger Wiklund wrote:
>    Hi
>    I played around with IPv6 on my Mac today (Mac OS Catalina) and I noticed
>    that besides the IP from DHCPv6 (dynamic) it's also generating two other
>    addresses.
[...]
>    I don't really know that the "secured" address is used for TBH (both
>    autoconf are randomized and not based on the MAC)
>    The temporary address is used for outgoing connections and is changed
>    every so often.

>    When I read DHCPv6 vs SLAAC it often boils down to "control" but I don't
>    see the need to allocate a dynamic address if the autogenerated are used.
>    For client's you dont really have any inbound connections unless it's a
>    support case.

Ha! Yes, you're arguing from a client perspective. When I am in a bigger
environemnt, a lot of machines need to be addressable (be it for services
outside their local link, be it to secure access to special infrastructure
to a limited set of clients, be it for pulled backups, to name a few.

@work I use lots of dhcpv6 in these cases. We specifically don't
use it on the WLAN where personal devices live; those use the
autoconf'd tmp addresses, and pooled natted DHCP addresses for V4.

Regards,
	-is