DHCP for multiple subnets (was: Re: Routing and bandwidth problem)

[Luciano Miguel Ferreira Rocha]

On Sun, Jun 13, 2004 at 05:04:47PM -0600, Rodolfo J. Paiz wrote:
> At 13:41 6/13/2004, Luciano Miguel Ferreira Rocha wrote:
> >On Sun, Jun 13, 2004 at 01:08:32PM -0600, Rodolfo J. Paiz wrote:
> >>         1. You *should* configure your dhcpd.conf for every subnet on
> >> which your server has an interface even if the DHCP server does not 
> >assign
> >> addresses (i.e. the subnet block does not include a range statement).
> >
> >No need, you can specify the interfaces that the dhcp server will listen
> >on in /etc/sysconfig/dhcpd:
> >DHCPDARGS="eth1 eth2"
> 
> Entirely separate and different topics, even though you are correct. In my 
> case I have eth0 to the Internet and eth1-eth4 to the local networks. I 
> *do* have dhcpd set to listen on every interface *except* eth0. Wouldn't 
> want to attempt to serve DHCP to my Internet Service Provider.
> 
> However, what I said above refers to the fact that dhcpd *must* know about 
> every subnet configured on the box even if it does not assign addresses on 
> that subnet or listen on that interface. Why? Apparently (according to its 
> maintainers) matching the subnet with the interface is how it determines 
> with certainty which address to assign.

No, there's no need to have a subnet configured for an interface that
the server isn't listening on.

It would be a nightmare otherwise, in my case, as the eth2 interface is
connected to the internet with a dynamic ip, and it often changes
networks.

Regards,
Luciano Rocha