two interfaces, same range

[Glenn Satchell]

>X-Greylist: delayed 1016 seconds by postgrey-1.27 at post.isc.org; Tue, 03 Jul 
2007 22:22:01 UTC
>Date: Tue, 03 Jul 2007 19:04:57 -0300
>From: mateus <mateus at spectra.homelinux.org>
>To: dhcp-users at isc.org
>Subject: two interfaces, same range
>X-archive-position: 4008
>X-ecartis-version: Ecartis v1.0.0
>X-original-sender: mateus at spectra.homelinux.org
>List-software: Ecartis version 1.0.0
>X-List-ID: <dhcp-users.isc.org>
>X-list: dhcp-users
>
>hello,
>
>i have a server with two interfaces, each interface is conected with a 
>different switch, i need to do this:
>eth0 - range 192.168.0.10 192.168.0.100
>eth1 - range 192.168.0.110 192.168.0.200
>
>how can i do this? im using debian 4
>
>regards
>
A little more information is required to understand your requirements.
Could you provide the IP address and subnet mask for each interface
(eth0 and eth1), and the network addresses on each interface. And a
brief description of how the addresses are arranged on the different
switches and subnets.

As a guess, are both interfaces on the server and the switches part of
the same subnet? You want to assign addresses from a different range
depending on which interface the request came in on? If this is not the
case please provide the information as described above and ignore the
rest of the message!

If this is the case, then you cannot really do what that. A dhcp client
sends a broadcast request (called a DHCPDISCOVER) which will be seen by
both interfaces. THe dhcp server will send a response (called a
DHCPOFFER) for each request. The dhcp server doesn't really know or
care which interface the DHCPDISCOVER came in on, so it can't
differentiate the requests that way.

So you can create a single subnet definition to handle the whole range,
eg:

subnet 192.168.0.0 netmask 255.255.255.0 {
  range 192.168.0.10 192.168.0.100;
  range 192.168.0.110 192.168.0.200;
  <other options>
}

and the addresses will be selected from each range.

regards,
-glenn