On 01/15/2017 09:11 AM, Gregory P. Ennis wrote: > All I can say is that when I looked at the dhcpd.conf examples and read > the man pages as well as the explanations of how dhcpd works, we should > be able to use dhcpd for more than one subnet : You can, provided they're on different physical interfaces. I'm mostly certain you can have two DHCP scopes on one physical interface, provided that the DHCP server itself only has addresses on one of them. That is, if eth0 has 192.168.1.9 and only that address, you should be able to offer addresses for 192.168.1.0/24 and also 192.168.2.0/24 on that interface. Any host you want to assign an address in 192.168.2.0/24 will have to be manually added to that subnet with a "host" entry in dhcpd.conf. Otherwise, imagine that you have an Ethernet LAN that includes a WAP. When the DHCP server gets a request from a new host, how does it know whether that client is on Ethernet or WiFi? There's no indication in the request the server receives that indicates which media the client is using. However, attaching two IP subnets to the same broadcast domain is usually a bad idea. Networks are typically segregated for one of two reasons: either to establish access controls or to reduce traffic to improve service. You'll accomplish neither. Hosts on each subnet won't be able to communicate with each other directly, but they will all see all of the address discovery traffic broadcast on the network. A host that wanted to communicate with a host in another subnet could simply add a new address manually and bypass any access controls that the router had in place. Worse, because any communication you *do* want to allow has to pass to the router and then be sent back out the same network interface, you've actually doubled the amount of traffic on your LAN. Having multiple subnets on a single broadcast domain can be an interesting, inexpensive way to experiment with access control or simulate multihosting, but you don't want to do it for any longer than is necessary for experimental purposes.