what is the subtil difference between max-lease-time and default-lease-time ?

[Sébastien CRAMATTE]

Hello

Does anyone could explain me what is the subtil difference between  
max-lease-time and default-lease-time ?
To test purpose I've put the same value for  twice in my "dhcpd.conf"

My problem is that I don't understand why state is always active and  
why starts time of the current lease is inferior to  ends  time of the 
previous ?

Any ideas and some explications ?
Thanks for your help

Regards

Sebastien
---------------- dhcpd.conf ------------------

default-lease-time 3600;
max-lease-time 3600;

ddns-update-style none;

log-facility local7;

subnet 192.168.1.0 netmask 255.255.254.0 {
         option routers 192.168.1.1;
         option domain-name "cpe.telelorca.com";
         option ntp-servers ntp.telelorca.com;
         option domain-name-servers 192.168.1.2,192.168.1.3;

         one-lease-per-client on;

         pool {
           deny dynamic bootp clients;
           default-lease-time 300;
           max-lease-time 300;
           range 192.168.1.50 192.168.1.254;
         }



--------------- /var/lib/dhcp3/dhcpd.leases ---------------


# All times in this file are in UTC (GMT), not your local timezone.   
This is
# not a bug, so please don't ask about it.   There is no portable way to
# store leases in the local timezone, so please don't request this as a
# feature.   If this is inconvenient or confusing to you, we sincerely
# apologize.   Seriously, though - don't ask.
# The format of this file is documented in the dhcpd.leases(5) manual page.
# This lease file was written by isc-dhcp-V3.0.4

lease 192.168.1.50 {
  starts 1 2006/07/10 10:53:15;
  ends 1 2006/07/10 10:56:35;
  tstp 1 2006/07/10 10:56:35;
  binding state active;
  next binding state free;
  hardware ethernet 00:00:00:00:00:00;
  uid "\001\000\017 #U\200";
  client-hostname "tv";
}
lease 192.168.1.50 {
  starts 1 2006/07/10 10:54:55;
  ends 1 2006/07/10 10:55:45;
  binding state active;
  next binding state free;
  hardware ethernet 00:00:00:00:00:00;
  uid "\001\000\017 #U\200";
  client-hostname "tv";
}
lease 192.168.1.50 {
  starts 1 2006/07/10 10:55:20;
  ends 1 2006/07/10 10:56:10;
  binding state active;
  next binding state free;
  hardware ethernet 00:00:00:00:00:00;
  uid "\001\000\017 #U\200";
  client-hostname "tv";
}
....