Two consecutive lease entries for same MAC address

[Reissom Beshir]

Simon Hobson wrote:

>>Can anyone please tell me why dhcpd ( ancient V3.0rc4 ) give two different 
>>IP addresses even if the MAC is the same ?
>
> It's a classic "dual boot" problem where one client does not provide a UID 
> (aka Client-ID) and another does. The standard *requires* that the DHCP 
> server use the supplied Client-ID as the primary key, and the MAC address 
> only if no Client-ID is supplied.
>
> Thus the two clients ARE DIFFERNET devices as far as the DHCP server is 
> concerned, and so they get different addresses.

Have you considered using the MAC address as the UID when the UID is not 
provided by the client.  That way the client receives the same address when 
the UID happens to be the same value as the MAC address as the case here.

>>lease 10.53.39.212 {
> <...>
>>   hardware ethernet 00:d0:b7:40:9d:aa;
>>   set vendor-string = "PXEClient:Arch:00000:UNDI:002001";
>>}
>>lease 10.53.39.247 {
> <...>
>>   hardware ethernet 00:d0:b7:40:9d:aa;
>>   uid "\001\000\320\267@\235\252";
>>   set vendor-string = "udhcp 0.9.9-pre";
>>   set ddns-fwd-name = "derma-vormerk.sb-brixen.it";
>>   set ddns-rev-name = "247.39.53.10.in-addr.arpa.";
>>   client-hostname "derma-vormerk";
> <...>
>>}