Warning: subnet overlaps subnet

Simon Hobson dhcp1 at thehobsons.co.uk
Wed Mar 19 07:43:39 UTC 2008

I wrote:

>I 'think' you can do :
>Make the server authoritative AND remove (comment out) all 
>pools/range declarations.
>From man dhcpd.conf :
>Another option is to firewall packets.

How strange, it's left out the bit I copied from a terminal window. 
The bit I was quoting should have said :

>If the server finds the address the client is requesting, and that 
>address is available to the client, the server will send a DHCPACK. 
>If the address is no longer available, or the client isn't permitted 
>to have it, the  server will send a DHCPNAK. If the server knows 
>nothing about the address, it will remain silent, unless the address 
>is incorrect for the network segment to which the client has  been 
>attached  and  the  server  is authoritative  for  that  network 
>segment, in which case the server will send a DHCPNAK even though it 
>doesn't know about the address.

The key bit there is "If the server knows nothing about the address, 
it will remain silent", so simply commenting out any range statements 
should be sufficient for the server to silently ignore any requests.

It will still respond to requests from hosts with fixed addresses, 
and it will still NAK requests for addresses outside the subnet.

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