dhcpcd-discuss

On 2016-06-07 00:28, Neal P. Murphy wrote:
> With my analogy, everyone eats less than they hoped for. (I trust
> you've shared a pizza from time to time. There've been times I get one
> or two slices and the rest is gone by the time I reach for a third.)
> With dhcpcd (a /64 instead of a /60), *one* gets the whole thing and
> the rest starve.

No, that's not right.
dhcpcd can split a 60 across many interfaces if you're wanting a 64 on 
each delegated interface.

Show me your config and what you expect please.

> It's more to do with consistency. PD is supposed to provide
> consistent, repeatable results. Given a consistent DUID, the
> requesting router is supposed to get the same prefix every time from
> the delegating router.

Supposed to yes, but there is no guarantee this will be the case.

> If a business gets a /60 this hour, then gets a
> different /60 the next hour, they have to change all of their DNS
> (private and public), re-address all hosts, and deal with the flood of
> calls to their help desk. When a business asks for a /60, it is
> reasonable that they should expect to receive a /60 for their 12
> internal LANs. Getting a /64 is little different from receiving
> nothing at all; 11/12 of their business is still down (think VoIP
> phones). People don't want the public (or private) addresses on their
> internal LANs changing. (Never mind that the spec says that both the
> old and the new addresses must both be active for some period of time;
> that leads to an operational nightmare, especially where a stateful
> firewall is involved.)

If you get a /64 and want to delegate to >1 interface as /64 AND have 
none zero or default SLA's assigned then dhcpcd will refuse to configure 
it because it will be too big.
If on the other hand the prefix delegation just changes from dead to 
beef then you have two choices - suck it up and re-number or complain to 
your ISP to change it back.
In this scenario your hosts will be able to access the internet, just 
not anyone able to access them by DNS.

But it's not outside the realm of possibility to renumber your hosts in 
DNS. A well formed config file would just change the prefix which should 
be quite straight forward.

This matches the long standing IPv4 practice.

But instead of us debating, I'm happy to add a config option to only 
work with the given prefix and refuse others.
The length option should be fine as is.

Roy