Force DHCP expiry

Alex Moen alexm at
Mon Apr 4 15:54:27 UTC 2011

Hi all,

I know this question has been asked in the past, but no real  
resolutions were posted to the questions.  So, I will try again, since  
the only referenced I can find were from 5 years ago.

Here is a snippet of my config:

shared-network MY-TEST {
subnet netmask {}
subnet netmask {
         option routers;
         option subnet-mask;
	option broadcast-address;
         default-lease-time 43200;
         max-lease-time 43200;
         min-lease-time 43200;

class "DSLAM1-INT_0.0-VLAN_3100" {
         match if ( option agent.remote-id="DSLAM1" ) and
                  ( binary-to-ascii (10, 8, ".", substring( option  
agent.circuit-id, 0, 2)) = "0.0" ) and
                  ( binary-to-ascii (10, 16, "", substring( option  
agent.circuit-id, 2, 2)) = "3100" );
pool {
         allow members of "DSLAM1-INT_0.0-VLAN_3100";

So, I am defining a single IP address pool for each interface that an  
ONT or modem is using.  The problem comes in when changing out ONTs or  
modems (with a different MAC address), when the lease has not yet  

What is the proper way to clear the lease so that the new device can  
be OFFERED the same ip address as the old device?  Is this able to be  
automated inside of the pool or subnet statement itself?

Thanks for any advice...

Alex Moen

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