[En-Nut-Discussion] DHCP on multiple interfaces?

[Ulrich Prinz]

Bernd Walter schrieb:
> On Sat, Dec 12, 2009 at 12:48:22AM +0100, Ulrich Prinz wrote:
>> Hi!
>>
  > If you need to configure for your network DHCP gets pretty much
> useless.
> you can still setup the remaining parameters, but there is not much
> left.

Besides auto-config of the network part left, assignement of bootp/tftp, 
ntp-server and some others, yes. But that's pretty much on top that 
still qualifies DHCP half-configuration for use.
> 
 > [...]
> Beside from fixed setting by MAC you can also group by MAC range and
> system type.
> Ethernut client for example identifies themself as being ethernut.
> You can't do this with a cheap DSL router's DHCPd, but with such a beast
> you will not run complex network setup anyway.

Yes, that's what I said / meant. With a real dhcpd you have a lot of 
options normally no one knows about.
> 
>> ***... And then *** 
 >> we may have a 255.255.255.255 problem. I would not write a
> 
> Sure, but this can't work for DHCP, because it's a chicken-egg problem.
> DHCP runs without IP being configured for the required interface.

Hm, read the text again...
With IP-Layer not configured you cannot route anything, not even 
255.255.255.255. But you can do DHCP, as it works on MAC layer.
**After** you've done DHCP, IP-layer is up and you can handle such packets.

:) Best regards, Ulrich