dhcpd.leases

[Ragnar Wisloff <ragnar@skolelinux.no>]

I'm observing a puzzling problem. On schools with a number of thin 
clients that all use dynamic addresses and the number of clients 
approach the number of dynamic addresses allocated in dhcpd.conf, the 
dhcpd daemon will after some time report "no free leases" and refuse to 
hand out IPs. It seems that the dhcp request sent out by the thin client 
is subtly different the first and second time (two dhcp requests are 
sent during a single boot). The second dhcp request contains more 
information, and the dhcpd server sees this as a different request. Even 
if the mac address is the same, they have different uids and so a 
different IP is handed out. These two stanzas from a leases file shows 
this behaviour:

lease 192.168.199.184 {
  starts 3 2005/05/25 07:57:55;
  ends 4 2005/05/26 07:57:55;
  binding state active;
  next binding state free;
  hardware ethernet 00:50:8b:c9:38:ef;
}
lease 192.168.199.180 {
  starts 3 2005/05/25 07:58:06;
  ends 4 2005/05/26 07:58:06;
  binding state active;
  next binding state free;
  hardware ethernet 00:50:8b:c9:38:ef;
  uid "\001\000P\213\3118\357";
}

I'm wondering if the symptom is seen on other systems. This particular 
school just had a reinstall to sarge, and the problems started then.

The problem is solvable, but I would like to hear if this is just a 
freak problem or one that can be reproduced.


--
Med vennlig hilsen
Ragnar Wisløff
-------------
life is a reach. then you gybe.