Two different IP addresses leased out to the same device

[Markus Zuercher]

i list

I have one device which constantly receives different IP addresses
given out from a single DHCPD 4.1.0 server.

For a better understanding, this is the lease database of the server:

lease 10.10.0.2 {
  starts 3 2009/09/09 14:24:53;
  ends 4 2009/09/10 14:24:53;
  tstp 4 2009/09/10 14:24:53;
  cltt 3 2009/09/09 14:24:53;
  binding state active;
  next binding state free;
  hardware ethernet xx:xx:xx:xx:xx:xx;
  uid "\001\000\011k\007\346z";
  option agent.circuit-id 0:96:0:41;
  option agent.remote-id 0:1e:69:xx:xx:xx;
  client-hostname "privat";
}
lease 10.10.0.238 {
  starts 3 2009/09/09 14:28:14;
  ends 4 2009/09/10 14:28:14;
  tstp 4 2009/09/10 14:28:14;
  cltt 3 2009/09/09 14:28:14;
  binding state active;
  next binding state free;
  hardware ethernet xx:xx:xx:xx:xx:xx;
  option agent.circuit-id 0:8a:0:41;
  option agent.remote-id 0:18:9b:xx:xx:xx;
  client-hostname "support-laptop";
}

As you can see, the MAC address of the second lease is the same as in
the first lease, but a different IP address. However, the first one
was active at this time.

In my understanding, this can not happen, the server would reassign
the same IP or deny any other IP.

Only difference is the agent.remote-id (and agent.circuit-id,
respectively). This is a problem in our environment because I cannot
assume that the agent.remote-id is never changed.

Thanks for any information about this issue.