DHCP code in 2.0.4+

[Alan DeKok]

Karl Auer wrote:
> Perhaps you've just been unlucky? It's just as good an argument.

  Well-designed systems don't require luck to work.  That's my argument.

>>   See the RELNOTES that is included with ISC for a
>> series of bug fixes to the protocol.  Both the implementation and the
>> protocol design have been changed substantially to avoid issues seen by
>> real-live people in the field.
> 
> Good. That's to be expected and a good thing.

  Umm.... no.  It means they protocol was designed from an incomplete
problem statement, and an incomplete knowledge of the system.  That
isn't good engineering practice.

>>   Yes.  A few quick tests demonstrated that failure.  See earlier
>> messages in this thread.
> 
> Nope - "tests" do not show a theoretical failure.

  See earlier messages in this thread.  I (a) found a theoretical issue
with the protocol, and (b) demonstrated it in a live system.

  It's a fundamental design flaw.

  There are designs which are definitely better.  Database replication,
for one.  Yes, it doesn't implement the various states that the ISC
protocol uses.  However, those states are largely there because of
implementation decisions, rather than theoretical analysis.

  Alan DeKok.