vim /var/lib/dhcpd/dhcpd.leases

lease 163.17.209.175 {
  starts 1 2013/05/27 00:02:01;
  ends 1 2013/05/27 00:32:26;
  tstp 1 2013/05/27 00:29:46;
  cltt 1 2013/05/27 00:02:01;
  binding state free;
}