dhcp ( & cisco related ) question

[Ken Roberts]

On Tue, 2006-08-08 at 14:36, Petre Bandac wrote:
> > The pertinent configuration for the Cisco gear (assuming a 3550 layer
> > 3 switch) is:
> > ip dhcp relay information option
> > no ip dhcp relay information check
> > 
> > and then, for each VLAN:
> > ip helper-address 192.168.3.12
> > ip helper-address 192.168.3.13
> > 
> > For your dhcp configuration, create your subnets the way you would
> > think.  The router will send along enough information so that dhcpd
> > can figure out which subnet you're on.
> 
> ok here too, with the observation that the 3560 router will act as a
> gateway with the ip put on the vlan; however, this observation becomes a
> nonsense if the interface which relays does not have to be "unnumbered"


I don't understand what you're saying here.  I'm not an expert, but I
did get my Cisco gear to work with dhcpd.  You're suggesting a DHCP
request for which there is no defined network information?  Assuming
your router is configured, how would that even work?

My 3550 stack acts as the router for each VLAN.  The way I understand
it, for each VLAN where the switch acts as a router, the router must
have at least one IP address on that VLAN.

Is this a correct statement?  Or maybe I completely missed what you're
trying to say?