dhcpcd-discuss

On 21/04/2017 19:24, Harald Dunkel wrote:
> You are lucky. Deutsche Telekom wants to see extra money for a
> "Geschaeftskundenanschluss" to give me the same /56 prefix.
>
> IMHO DT violates rfc 3633: "During renumbering it is expected that
> the old and the new prefix co-exist for some time." Maybe the rfc is
> too vague here.

The RFC is fine, and strictly speaking so is DT because it does
co-exist, it's just not managed by DHCPv6 any longer.

It could be argues that "co-exist" means "included in the DHCP 
transaction with a pltime of 0".

> rfc 3633 also mentions explicitly (section 12.1) a "Rebind/Reply
> message" for the case that the router is rebooted or that the
> connection is reset on a lower level. Is this missing or
> misconfigured in my setup somehow? Anything I could fix in my config
> file?

No, the rebind message is fine according to wireshark on your prior
capture. This is something strictly with DT.
It could be argued that dhcpcd should still remember existing 
delegations that are no longer leased but that's a lot of work for very 
little gain. It could also be argued that if you want to clear 
everything then rebooting the router is also fine.

> > What you describe is different to the usual "deprecated" case as
> > the address is expected to _not_ work any more. Maybe in the
> > "failed to rebind" case it would make sense to just remove the
> > address, or maybe keep it but reset pltime to 0 to allow local
> > connections to the old address to stay working. This would be under
> > dhcpcd's control rather than the kernel.
>
> Roy mentioned this, too. This sounds like a new feature. I wonder if
> this could be included in dhcpcd 6.x?

Definitely not in dhcpcd-6 - development there is now halted unless 
something like a security issue arises.
It's also too late for dhcpcd-7.0.0 as that should be entering the final 
RC process soon, once that's complete new features will then be considered.
The feature itself is non trivial and there's other more pressing 
features that need being added.

If it's something you really want I suggest creating a new task here:
https://dev.marples.name/maniphest/

Roy