http://isc-dhcp-users.193.s1.nabble.com/Problem-with-shared-network-tp145p161.html
> On Thu, Jun 4, 2015 at 1:38 PM, <
[hidden email]> wrote:
>
>> <aside>I use ignore rather than deny to keep my logs cleaner. Deny logs
>> every attempt. The ignore just ignores. And yes, I realize mac filtering
>> can be easily defeated by a knowledgeable opponent. A weak attempt at
>> security is not my purpose for using mac lists.</aside>
>>
>> I did not have pools. Now I do. Unfortunately, I still get the same
>> behavior. Just for kicks, I reversed the order of the subnets, and to my
>> surprise, still got the same behavior, except now the 192 subnet still
>> works. So the pools helped. This makes me believe the problem is the 10
>> subnet declaration.
>>
>> I removed the 192 subnet and the shared-network and just left the 10
>> subnet. When I attempted to restart the DHCP server, I got the no subnet
>> declaration for eth0 and it exited. Adding eth0:1 to both the command
>> line
>> and /etc/defaults/isc-dhcp-server did not change the result, only the
>> error message: "No subnet declaration for eth0:1 (No IPv4 addresses)"
>>
>> DHCP needs the 192 subnet to be defined. It does not need to have a
> range, or any options, it can be an empty definition, but if it is not
> defined, it will ignore that interface.
I agree that is the reason for the first error message (the eth0). But on
address. At the time (now changed), ONLY 10.111.111.1 was on eth0:1.